Prospective Validation of First-Trimester Screening for Preterm Preeclampsia in Nulliparous Women (PREDICTION Study).

BACKGROUND: Fetal Medicine Foundation (FMF) studies suggest that preterm preeclampsia can be predicted in the first trimester by combining biophysical, biochemical, and ultrasound markers and prevented using aspirin. We aimed to evaluate the FMF preterm preeclampsia screening test in nulliparous women. METHODS: We conducted a prospective multicenter cohort study of nulliparous women recruited at 11 to 14 weeks. Maternal characteristics, mean arterial blood pressure, PAPP-A (pregnancy-associated plasma protein A), PlGF (placental growth factor) in maternal blood, and uterine artery pulsatility index were collected at recruitment. The risk of preterm preeclampsia was calculated by a third party blinded to pregnancy outcomes. Receiver operating characteristic curves were used to estimate the detection rate (sensitivity) and the false-positive rate (1-specificity) for preterm (<37 weeks) and for early-onset (<34 weeks) preeclampsia according to the FMF screening test and according to the American College of Obstetricians and Gynecologists criteria. RESULTS: We recruited 7554 participants including 7325 (97%) who remained eligible after 20 weeks of which 65 (0.9%) developed preterm preeclampsia, and 22 (0.3%) developed early-onset preeclampsia. Using the FMF algorithm (cutoff of ≥1 in 110 for preterm preeclampsia), the detection rate was 63.1% for preterm preeclampsia and 77.3% for early-onset preeclampsia at a false-positive rate of 15.8%. Using the American College of Obstetricians and Gynecologists criteria, the equivalent detection rates would have been 61.5% and 59.1%, respectively, for a false-positive rate of 34.3%. CONCLUSIONS: The first-trimester FMF preeclampsia screening test predicts two-thirds of preterm preeclampsia and three-quarters of early-onset preeclampsia in nulliparous women, with a false-positive rate of ≈16%. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT02189148.

Fetal Cardiology Bioethics: An Innovative New Curriculum for Cardiology Trainees.

Decision-making in fetal cardiology is fraught with ethical issues yet education in bioethics for trainees is limited or nonexistent. In this innovation report, we describe the development of a fetal cardiology bioethics curriculum designed to address this gap. The curriculum was developed to supplement the core curriculum for cardiology fellows and fetal cardiology subspecialty trainees. The series combines didactic and interactive teaching modalities and contains 5 key components: (1) introduction to bioethics and its role in fetal cardiology, (2) counseling and pathways for compassionate terminal care, (3) case vignette-based ethical analysis and discussion cases, (4) fetal counseling considerations for shared decision-making and recommendations, (5) facilitated communications role play. The curriculum was refined using session evaluations from end users. This report describes the innovative curriculum as a starting point for further incorporation and study of bioethical education in pediatric cardiology and fetal training programs.

Implementation of Multiple Marker Screening for Preterm Preeclampsia in a Single Tertiary Obstetric Centre.

OBJECTIVES: Early assessment of pregnant individuals for risk of preterm preeclampsia (PE) is possible at the 11-14 week ultrasound visit using a validated multiple marker algorithm, allowing timely use of preventative low-dose acetylsalicylic acid (LDA) in high-risk patients. With no established early screening program for preterm PE in Canada, our objectives were to assess the acceptability and operational impact of routine screening for preterm PE during the 11-14 week ultrasound visit, evaluate uptake and adherence to LDA when recommended, and assess screening performance. METHODS: A prospective implementation study of preterm PE screening among pregnant patients at the ultrasound unit of a tertiary obstetric centre in Toronto, Canada. RESULTS: A total of 1057 patients were screened, with an acceptance rate of 87.1%. First-trimester ultrasound appointment time increased by a median time of 7 minutes (Interquartile range 6-9). By 16 weeks gestation, 88.7% of high-risk patients had started LDA, with adherence of 88.7%‒94.6% from 16‒36 weeks. Satisfaction with counselling was ≥7/10 in more than 95% of patients. There were 7 cases of preterm PE (0.73%), 3 in the low-risk group (0.35%), and 4 in the high-risk group (4.1%). When accounting for LDA use, the treatment-adjusted detection rate was 78.6%. CONCLUSIONS: We demonstrate successful implementation of a validated, effective screening and prevention program for preterm PE as a first step in the implementation of a broader program adaptable for cultural, access/equity considerations, and marker availability.

Maternal First-Trimester Alpha-Fetoprotein and Placenta-Mediated Pregnancy Complications.

BACKGROUND: Maternal serum markers used for trisomy 21 screening are associated with placenta-mediated complications. Recently, there has been a transition from the traditional first-trimester screening (FTS) that included PAPP-A (pregnancy-associated plasma protein-A) and beta-hCG (human chorionic gonadotropin), to the enhanced FTS test, which added first-trimester AFP (alpha-fetoprotein) and PlGF (placental growth factor). However, whether elevated first-trimester AFP has a similar association with placenta-mediated complications to that observed for elevated second-trimester AFP remains unclear. Our objective was to estimate the association of first-trimester AFP with placenta-mediated complications and compare it with the corresponding associations of second-trimester AFP and other first-trimester serum markers. METHODS: Retrospective population-based cohort study of women who underwent trisomy 21 screening in Ontario, Canada (2013-2019). The association of first-trimester AFP with placenta-mediated complications was estimated and compared with that of the traditional serum markers. The primary outcome was a composite of stillbirth or preterm placental complications (preeclampsia, birthweight less than third centile, or placental abruption). RESULTS: A total of 244 990 and 96 167 women underwent FTS and enhanced FTS test screening, respectively. All markers were associated with the primary outcome, but the association for elevated first-trimester AFP (adjusted relative risk [aRR], 1.57 [95% CI, 1.37-1.81]) was weaker than that observed for low PAPP-A (aRR, 2.48 [95% CI, 2.2-2.8]), low PlGF (aRR, 2.28 [95% CI, 1.97-2.64]), and elevated second-trimester AFP (aRR, 1.97 [95% CI, 1.81-2.15]). When the models were adjusted for all 4 enhanced FTS test markers, elevated first-trimester AFP was no longer associated with the primary outcome (aRR, 0.77 [95% CI, 0.58-1.02]). CONCLUSIONS: Unlike second-trimester AFP, elevated first-trimester AFP is not an independent risk factor for placenta-mediated complications.

The Implementation of Preeclampsia Screening and Prevention (IMPRESS) Study.

BACKGROUND: Preeclampsia affects between 2% and 5% of pregnancies and is one of the leading causes of perinatal morbidity and mortality worldwide. Despite strong evidence that the combination of systematic preeclampsia screening based on the Fetal Medicine Foundation preeclampsia risk calculation algorithm with treatment of high-risk patients with low-dose aspirin reduces the incidence of preterm preeclampsia more than currently used risk-factor-based screening, real-world implementation studies have not yet been done in Canada. OBJECTIVE: This study aimed to assess the operational feasibility of implementing first-trimester screening and prevention of preterm preeclampsia (<37 weeks) alongside a publicly funded first-trimester combined screening program for aneuploidies. STUDY DESIGN: This was a prospective implementation study. Consecutive pregnant patients referred for first-trimester combined screening (11-13+6 weeks) were offered screening for preeclampsia based on the Fetal Medicine Foundation algorithm concomitantly with their aneuploidy screen. Consenting participants were screened using maternal risk factors, mean arterial pressure, uterine artery Doppler pulsatility index, pregnancy-associated plasma protein-A, and placental growth factor. Risk for preterm preeclampsia (<37 weeks) was calculated using the Fetal Medicine Foundation algorithm, and individuals with a risk score ≥1 per 100 were recommended to use aspirin (162 mg once daily at bedtime, <16-36 weeks). Implementation metrics assessed included: acceptability, operational impact, proportion of aspirin initiation, quality and safety measures, and screen performance. RESULTS: Between December 1, 2020 and April 23, 2021, 1124 patients consented to preeclampsia screening (98.3% uptake), and 92 (8.2%) screened positive. Appointments for patients receiving first-trimester combined screening aneuploidy and preeclampsia screening averaged 6 minutes longer than first-trimester combined screening alone, and adding uterine artery Doppler pulsatility index averaged 2 minutes. Of the 92 patients who screened as high-risk for preeclampsia, 72 (78.3%) were successfully contacted before 16 weeks' gestation. Of these, 62 (86.1%) initiated aspirin, and 10 (13.9%) did not. Performance audit identified a consistent negative bias with mean arterial pressure measurements (median multiple of the median <1 in 10%); other variables were satisfactory. There were 7 cases of preterm preeclampsia (0.69%): 5 and 2 in the high- and low-risk groups, respectively. Screening detected 5 of 7 (71.4 %) preterm preeclampsia cases, with improved performance after adjustment for aspirin treatment effect. CONCLUSION: This study confirms the operational feasibility of implementing an evidence-based preeclampsia screening and prevention program in a publicly funded Canadian setting. This will facilitate implementation into clinical service and the scaling up of this program at a regional and provincial level.

Cost-effectiveness of noninvasive fetal RhD blood group genotyping in nonalloimmunized and alloimmunized pregnancies.

BACKGROUND: We sought to determine the cost-effectiveness of noninvasive fetal RhD blood group genotyping in nonalloimmunized and alloimmunized pregnancies in Canada. STUDY DESIGN AND METHODS: We developed two probabilistic state-transition (Markov) microsimulation models to compare fetal genotyping followed by targeted management versus usual care (i.e., universal Rh immunoglobulin [RhIG] prophylaxis in nonalloimmunized RhD-negative pregnancies, or universal intensive monitoring in alloimmunized pregnancies). The reference case considered a healthcare payer perspective and a 10-year time horizon. Sensitivity analysis examined assumptions related to test cost, paternal screening, subsequent pregnancies, other alloantibodies (e.g., K, Rh c/C/E), societal perspective, and lifetime horizon. RESULTS: Fetal genotyping in nonalloimmunized pregnancies (at per-sample test cost of C$247/US$311) was associated with a slightly higher probability of maternal alloimmunization (22 vs. 21 per 10,000) and a reduced number of RhIG injections (1.427 vs. 1.795) than usual care. It was more expensive (C$154/US$194, 95% Credible Interval [CrI]: C$139/US$175-C$169/US$213) and had little impact on QALYs (0.0007, 95%CrI: -0.01-0.01). These results were sensitive to the test cost (threshold achieved at C$88/US$111), and inclusion of paternal screening. Fetal genotyping in alloimmunized pregnancies (at test cost of C$328/US$413) was less expensive (-C$6280/US$7903, 95% CrI: -C$6325/US$7959 to -C$6229/US$7838) and more effective (0.19 QALYs, 95% CrI 0.17-0.20) than usual care. These cost savings remained robust in sensitivity analyses. DISCUSSION: Noninvasive fetal RhD genotyping saves resources and represents good value for the management of alloimmunized pregnancies. If the cost of genotyping is substantially decreased, the targeted intervention can become a viable option for nonalloimmunized pregnancies.

Noninvasive Fetal RhD Blood Group Genotyping: A Systematic Review of Economic Evaluations.

OBJECTIVE: Noninvasive fetal rhesus D (RhD) blood group genotyping may prevent unnecessary use of anti-D immunoglobulin (RhIG) in non-alloimmunized RhD-negative pregnancies and can guide management of alloimmunized pregnancies. We conducted a systematic review of the economic literature to determine the cost-effectiveness of this intervention over usual care. DATA SOURCES: Systematic literature searches of bibliographic databases (Ovid MEDLINE, Embase, and Cochrane) until February 26, 2019, and auto-alerts until October 30, 2020, and of grey literature sources were performed to retrieve all English-language studies. STUDY SELECTION: We included studies done in serologically confirmed non-alloimmunized or alloimmunized RhD-negative pregnancies, comparing costs and effectiveness of the intervention versus usual care. DATA EXTRACTION AND SYNTHESIS: Two reviewers extracted data from the eligible studies and assessed their methodological quality (risk of bias) using the Quality of Health Economic Studies (QHES) and Drummond tools. We narratively synthesized findings. Our review included 8 economic studies that evaluated non-invasive fetal RhD genotyping followed by targeted RhIG prophylaxis in non-alloimmunized pregnancies. Five studies further considered a subsequent alloimmunized pregnancy. The cost-effectiveness of the intervention versus usual care (e.g., universal RhIG or prophylaxis conditional on results of paternal testing) for non-alloiummunized pregnancies was inconsistent. Two studies indicated greater benefits and lower costs for the intervention, and another 2 suggested a trade-off. In 4 studies, the intervention was less effective and costlier than alternatives. Three studies were determined to be of high quality by both tools. Two of these studies favoured the intervention, and one assessed benefits in quality-adjusted life-years. No study clearly examined the cost-effectiveness of repetitive use of fetal genotyping in multiple non-alloimmunized or alloimmunized pregnancies. The cost of genotyping was the most influential parameter. CONCLUSION: The cost-effectiveness of noninvasive fetal RhD genotyping for non-alloimmunized pregnancies varies between studies. Potential savings from targeted management of alloimmunized pregnancies requires further research.

Prevalence of Rheumatic Heart Disease and Other Cardiac Conditions in Low-Risk Pregnancies in Kenya: A Prospective Echocardiography Screening Study.

Background: Rheumatic heart disease (RHD) in sub-Saharan Africa contributes to significant cardiac morbidity and mortality, yet prevalence estimates of RHD lesions in pregnancy are lacking. Objectives: Our first aim was to evaluate women using echocardiography to estimate the prevalence of RHD and other cardiac lesions in low-risk pregnancies. Our second aim was to assess the feasibility of screening echocardiography and its acceptability to patients. Methods: We prospectively recruited 601 pregnant women from a low-risk antenatal clinic at a tertiary care maternity centre in Western Kenya. Women completed a questionnaire about past medical history and cardiac symptoms. They underwent standardized screening echocardiography to evaluate RHD and non-RHD associated cardiac lesions. Our primary outcome was RHD-associated cardiac lesions and our secondary outcome was a composite of any clinically-relevant cardiac lesion or echocardiography finding. We also recorded duration of screening echocardiography and its acceptability among pregnant women in this sample. Results: The point prevalence of RHD-associated cardiac lesions was 5.0/1,000 (95% confidence interval: 1.0-14.5), and the point prevalence of all clinically significant lesions/findings was 21.6/1,000 (11.6-36.7). Mean screening time was seven minutes (SD 1.7, range: 4-17) for women without cardiac abnormalities and 13 minutes (SD 4.6, range: 6-23) for women with abnormal findings. Echocardiography was acceptable to women with 74.2% agreeing to participate. Conclusions: The prevalence of clinically-relevant cardiac lesions was moderately high in a low-risk population of pregnant women in Western Kenya.

Comparing Maternal Serum Screening Markers Among IVF and Spontaneous Conceptions in Ontario Through Registry Data.

OBJECTIVE: The objectives of this study were as follows: (1) to investigate the accuracy of IVF identification on the prenatal screening record from prenatal screening laboratories; (2) to compare the screening markers in IVF and non-IVF pregnancies in the population of Ontario; and (3) to propose more appropriate IVF adjustment factors for the Ontario population. METHODS: Two years of IVF treatment, data from all fertility clinics in Ontario were merged with the corresponding prenatal screening data from all five prenatal screening labs. New adjustment factors for IVF were developed for each maternal serum screening marker and nuchal translucency measurement. Means and SDs and linear regression models were reported for all prenatal screening records, as well as for records that had IVF identified through the prenatal screening requisition and records that were identified through the Canadian Assisted Reproductive Technologies Register (CARTR) Plus database. RESULTS: Significant differences between IVF and non-IVF groups on the basis of the prenatal screening requisition information and CARTR Plus information were found among the ethnicity-adjusted mean multiple of the medians for alpha fetoprotein, first trimester pregnancy-associated plasma protein A, second trimester unconjugated estradiol, first trimester human chorionic gonadotropin, total human chorionic gonadotropin, and dimeric inhibin A. CONCLUSION: This study proposed alternate IVF adjustment factors that will produce more accurate screening results within the population of Ontario.

No. 348-Joint SOGC-CCMG Guideline: Update on Prenatal Screening for Fetal Aneuploidy, Fetal Anomalies, and Adverse Pregnancy Outcomes.

OBJECTIVE: To review the available prenatal screening options in light of the recent technical advances and to provide an update of previous guidelines in the field of prenatal screening. INTENDED USERS: Health care providers involved in prenatal screening, including general practitioners, obstetricians, midwives, maternal fetal medicine specialists, geneticists, and radiologists. TARGET POPULATION: All pregnant women receiving counselling and providing informed consent for prenatal screening. EVIDENCE: Published literature was retrieved through searches of Medline, PubMed, and the Cochrane Library in and prior to March 2016 using an appropriate controlled vocabulary (prenatal diagnosis, amniocentesis, chorionic villi sampling, non-invasive prenatal screening) and key words (prenatal screening, prenatal genetic counselling). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies written in English and published from January 1985 to May 2016. Searches were updated on a regular basis and incorporated in the guideline. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical speciality societies. GUIDELINE UPDATE: Evidence will be reviewed 5 years after publication to determine whether all or part of the guideline should be updated. However, if important new evidence is published prior to the 5-year cycle, the review process may be accelerated for a more rapid update of some recommendations.

Clinical outcomes after assisted reproductive technology in twin pregnancies: chorionicity-based comparison.

The chorionicity-based evaluation of the perinatal risk in twin pregnancies after assisted reproductive technology (ART) is lacking. A retrospective review was performed of all twin pregnancies monitored prenatally and delivered at our hospital between 2010 and 2014. Chorionicity was diagnosed by ultrasound examination at first trimester and confirmed by postnatal pathology. Pregnancy and perinatal outcomes were prospectively recorded. Adjusted odds ratios (aOR) with 95% confidence intervals (CI) were calculated in a logistic regression model. A total of 1153 twin pregnancies were analyzed. The occurrence of preterm premature rupture of membranes (PPROM) was 3 times as frequent in monochorionic diamniotic (MCDA) twin pregnancies after ART as in those spontaneous counterparts (aOR 3.0; 95%CI 1.1-3.2). The prevalence of intrahepatic cholestasis of pregnancies (ICP) was significantly higher in dichorionic diamniotic (DCDA) twin pregnancies following ART compared to spontaneous DCDA pregnancies (aOR 3.3; 95%CI 1.3-5.6). Perinatal outcomes did not differ between two conception methods, either in MCDA or DCDA twin pregnancies. Based on differentiation of chorionicity, ART is associated with the increased risk of PPROM in MCDA twin pregnancies and with a higher rate of ICP in DCDA twin gestations. ART does not increase adversity of perinatal outcomes in twin pregnancies.

Pre-conception Folic Acid and Multivitamin Supplementation for the Primary and Secondary Prevention of Neural Tube Defects and Other Folic Acid-Sensitive Congenital Anomalies.

OBJECTIVE: To provide updated information on the pre- and post-conception use of oral folic acid with or without a multivitamin/micronutrient supplement for the prevention of neural tube defects and other congenital anomalies. This will help physicians, midwives, nurses, and other health care workers to assist in the education of women about the proper use and dosage of folic acid/multivitamin supplementation before and during pregnancy. EVIDENCE: Published literature was retrieved through searches of PubMed, Medline, CINAHL, and the Cochrane Library in January 2011 using appropriate controlled vocabulary and key words (e.g., folic acid, prenatal multivitamins, folate sensitive birth defects, congenital anomaly risk reduction, pre-conception counselling). Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies published in English from 1985 and June 2014. Searches were updated on a regular basis and incorporated in the guideline to June 2014 Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Costs, risks, and benefits: The financial costs are those of daily vitamin supplementation and eating a healthy folate-enriched diet. The risks are of a reported association of dietary folic acid supplementation with fetal epigenetic modifications and with an increased likelihood of a twin pregnancy. These associations may require consideration before initiating folic acid supplementation. The benefit of folic acid oral supplementation or dietary folate intake combined with a multivitamin/micronutrient supplement is an associated decrease in neural tube defects and perhaps in other specific birth defects and obstetrical complications. VALUES: The quality of evidence in the document was rated using the criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1). Summary Statement In Canada multivitamin tablets with folic acid are usually available in 3 formats: regular over-the-counter multivitamins with 0.4 to 0.6 mg folic acid, prenatal over-the-counter multivitamins with 1.0 mg folic acid, and prescription multivitamins with 5.0 mg folic acid. (III) Recommendations 1. Women should be advised to maintain a healthy folate-rich diet; however, folic acid/multivitamin supplementation is needed to achieve the red blood cell folate levels associated with maximal protection against neural tube defect. (III-A) 2. All women in the reproductive age group (12-45 years of age) who have preserved fertility (a pregnancy is possible) should be advised about the benefits of folic acid in a multivitamin supplementation during medical wellness visits (birth control renewal, Pap testing, yearly gynaecological examination) whether or not a pregnancy is contemplated. Because so many pregnancies are unplanned, this applies to all women who may become pregnant. (III-A) 3. Folic acid supplementation is unlikely to mask vitamin B12 deficiency (pernicious anemia). Investigations (examination or laboratory) are not required prior to initiating folic acid supplementation for women with a risk for primary or recurrent neural tube or other folic acid-sensitive congenital anomalies who are considering a pregnancy. It is recommended that folic acid be taken in a multivitamin including 2.6 ug/day of vitamin B12 to mitigate even theoretical concerns. (II-2A) 4. Women at HIGH RISK, for whom a folic acid dose greater than 1 mg is indicated, taking a multivitamin tablet containing folic acid, should be advised to follow the product label and not to take more than 1 daily dose of the multivitamin supplement. Additional tablets containing only folic acid should be taken to achieve the desired dose. (II-2A) 5. Women with a LOW RISK for a neural tube defect or other folic acid-sensitive congenital anomaly and a male partner with low risk require a diet of folate-rich foods and a daily oral multivitamin supplement containing 0.4 mg folic acid for at least 2 to 3 months before conception, throughout the pregnancy, and for 4 to 6 weeks postpartum or as long as breast-feeding continues. (II-2A) 6. Women with a MODERATE RISK for a neural tube defect or other folic acid-sensitive congenital anomaly or a male partner with moderate risk require a diet of folate-rich foods and daily oral supplementation with a multivitamin containing 1.0 mg folic acid, beginning at least 3 months before conception. Women should continue this regime until 12 weeks' gestational age. (1-A) From 12 weeks' gestational age, continuing through the pregnancy, and for 4 to 6 weeks postpartum or as long as breast-feeding continues, continued daily supplementation should consist of a multivitamin with 0.4 to 1.0 mg folic acid. (II-2A) 7. Women with an increased or HIGH RISK for a neural tube defect, a male partner with a personal history of neural tube defect, or history of a previous neural tube defect pregnancy in either partner require a diet of folate-rich foods and a daily oral supplement with 4.0 mg folic acid for at least 3 months before conception and until 12 weeks' gestational age. From 12 weeks' gestational age, continuing throughout the pregnancy, and for 4 to 6 weeks postpartum or as long as breast-feeding continues, continued daily supplementation should consist of a multivitamin with 0.4 to 1.0 mg folic acid. (I-A). The same dietary and supplementation regime should be followed if either partner has had a previous pregnancy with a neural tube defect. (II-2A).

Objectif : Offrir des renseignements à jour sur l'utilisation pré et postconceptionnelle d'acide folique par voie orale, avec ou sans supplément de multivitamines / micronutriments, aux fins de la prévention des anomalies du tube neural et d'autres anomalies congénitales. Ces renseignements aideront les médecins, les sages-femmes, les infirmières et les autres professionnels de la santé à contribuer aux efforts de sensibilisation des femmes quant à l'utilisation et aux posologies adéquates de la supplémentation en acide folique / multivitamines, avant et pendant la grossesse. Résultats : La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans PubMed, Medline, CINAHL et la Cochrane Library en janvier 2011 au moyen d'un vocabulaire contrôlé et de mots clés appropriés (p. ex. « folic acid ¼, « prenatal multivitamins ¼, « folate sensitive birth defects ¼, « congenital anomaly risk reduction ¼, « pre-conception counselling ¼). Les résultats ont été restreints aux analyses systématiques, aux études observationnelles et aux essais comparatifs randomisés / essais cliniques comparatifs publiés en anglais entre 1985 et juin 2014. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en juin 2014. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques, et auprès de sociétés de spécialité médicale nationales et internationales. Coûts, risques et avantages : Les coûts financiers sont ceux de la supplémentation quotidienne en vitamines et de la consommation d'un régime alimentaire santé enrichi en folate. Les risques sont ceux qui sont liés à une association signalée entre la supplémentation alimentaire en acide folique et des modifications épigénétiques fœtales / la probabilité accrue d'obtenir une grossesse gémellaire. Ces associations pourraient devoir être prises en considération avant la mise en œuvre d'une supplémentation en acide folique. La supplémentation en acide folique par voie orale (ou l'apport alimentaire en folate combiné à un supplément de multivitamines / micronutriments) a pour avantage de mener à une baisse connexe du taux d'anomalies du tube neural et peut-être même des taux d'autres complications obstétricales et anomalies congénitales particulières. Valeurs : La qualité des résultats est évaluée au moyen des critères décrits par le Groupe d'étude canadien sur les soins de santé préventifs (Tableau). Déclaration sommaire 1. Au Canada, les comprimés de multivitamines comptant de l'acide folique sont habituellement offerts en 3 formats : multivitamines régulières en vente libre comptant de 0,4 à 0,6 mg d'acide folique, multivitamines prénatales en vente libre comptant 1,0 mg d'acide folique et multivitamines d'ordonnance comptant 5,0 mg d'acide folique. (III) Recommandations 1. Les femmes devraient se voir conseiller de maintenir un régime alimentaire santé riche en folate; la mise en œuvre d'une supplémentation en acide folique / multivitamines s'avère cependant requise pour leur assurer l'obtention des taux érythrocytaires de folate qui sont associés à l'octroi d'une protection maximale contre les anomalies du tube neural. (III-A) 2. Toutes les femmes en âge de procréer (12-45 ans) qui sont toujours fertiles (la grossesse demeure possible) devraient se voir offrir, dans le cadre de leurs consultations gynécologiques de dépistage (renouvellement de la contraception, test de Pap, examen gynécologique annuel), des services de counseling au sujet des avantages de l'acide folique administré sous forme d'une supplémentation multivitaminique, et ce, qu'elles envisagent ou non de connaître une grossesse. Puisqu'un si grand nombre de grossesses se manifestent de façon inattendue, cette recommandation s'applique à toutes les femmes qui pourraient devenir enceintes. (III-A) 3. La supplémentation en acide folique est peu susceptible de masquer la carence en vitamine B12 (anémie pernicieuse). La tenue d'explorations (examen ou épreuves de laboratoire) n'est pas requise avant la mise en œuvre d'une supplémentation en acide folique chez les femmes exposées à des risques d'anomalies du tube neural (ou d'autres anomalies congénitales sensibles à l'acide folique) primaires ou récurrentes qui envisagent une grossesse. Il est recommandé que l'acide folique soit administré sous forme de multivitamines comptant également 2,6 µg/jour de vitamine B12, de façon à atténuer toutes les préoccupations (même celles qui sont théoriques). (II-2A) 4. Les femmes exposées à des RISQUES ÉLEVÉS (pour lesquelles une dose d'acide folique supérieure à 1 mg s'avère indiquée) qui prennent des multivitamines contenant de l'acide folique devraient être avisées de respecter les consignes d'utilisation du produit en question et de ne pas prendre plus d'une dose quotidienne de supplément multivitaminique; ces femmes devraient plutôt prendre des comprimés additionnels ne contenant que de l'acide folique pour obtenir la dose requise. (II-2A) 5. Pendant au moins les deux à trois mois précédant la conception, tout au long de la grossesse et pendant de quatre à six semaines à la suite de l'accouchement (ou tant et aussi longtemps que se poursuit l'allaitement), les femmes qui sont exposées à un FAIBLE RISQUE d'anomalie du tube neural ou d'autres anomalies congénitales sensibles à l'acide folique et qui comptent un partenaire masculin également exposé à un faible risque doivent adopter un régime alimentaire composé d'aliments riches en folate et prendre un supplément multivitaminique oral quotidien contenant 0,4 mg d'acide folique. (II-2A) 6. À partir d'au moins trois mois avant la conception, les femmes qui sont exposées à un RISQUE MODÉRÉ d'anomalie du tube neural ou d'autres anomalies congénitales sensibles à l'acide folique et qui comptent un partenaire masculin également exposé à un risque modéré doivent adopter un régime alimentaire composé d'aliments riches en folate et prendre un supplément multivitaminique oral quotidien contenant 1 mg d'acide folique. Ces femmes devraient poursuivre l'utilisation de cette posologie jusqu'à l'atteinte d'un âge gestationnel de 12 semaines. (1-A) À partir de 12 semaines d'âge gestationnel, tout au long du reste de la grossesse et pendant de quatre à six semaines postpartum (ou tant et aussi longtemps que se poursuit l'allaitement), la supplémentation quotidienne utilisée devrait être composée d'une multivitamine contenant de 0,4 à 1,0 mg d'acide folique. (II-2A) 7. Pendant au moins trois mois avant la conception et jusqu'à l'atteinte d'un âge gestationnel de 12 semaines, les femmes qui sont exposées à un RISQUE ÉLEVÉ ou accru d'anomalie du tube neural et qui comptent un partenaire masculin présentant des antécédents personnels d'anomalie du tube neural (ou encore en présence d'antécédents personnels ou familiaux de grossesse affectée par une anomalie du tube neural chez l'un ou l'autre des partenaires) doivent adopter un régime alimentaire composé d'aliments riches en folate et prendre un supplément oral quotidien de 4 mg d'acide folique. À partir de 12 semaines d'âge gestationnel, tout au long du reste de la grossesse et pendant de quatre à six semaines postpartum (ou tant et aussi longtemps que se poursuit l'allaitement), la supplémentation quotidienne utilisée devrait être composée d'une multivitamine contenant de 0,4 à 1,0 mg d'acide folique. (I-A) Le même régime alimentaire et de supplémentation devrait être respecté en présence d'antécédents personnels ou familiaux de grossesse affectée par une anomalie du tube neural chez l'un ou l'autre des partenaires. (II-2A).

RETIRED: Technical Update: Preimplantation Genetic Diagnosis and Screening

This document has been archived because it contains outdated information. It should not be consulted for clinical use, but for historical research only. Please visit the journal website for the most recent guidelines.

Ce document a été archivé, car il contient des informations périmées. Il ne devrait pas être consulté pour un usage clinique, mais uniquement pour des recherches historiques. Veuillez consulter le site web du journal pour les directives les plus récentes.

Current practices in the prediction and prevention of preterm birth in patients with higher-order multiple gestations.

OBJECTIVE: We sought to determine the interventions utilized by maternal-fetal medicine specialists in the prediction and prevention of preterm labor in higher-order multiple (HOM) gestations. STUDY DESIGN: Online questionnaires and email surveys were sent to all the maternal-fetal medicine specialists in Canada (n=122). Questionnaire items included interventions physicians routinely recommended for HOM gestations including: (1) bed rest; (2) cervical length measurement on transvaginal ultrasound; (3) corticosteroids use; (4) cerclage; and (5) tocolytic therapy. RESULTS: Response rate was 66% (81/122), with 68% of respondents in practice for >10 years. Of physicians, 91% did not routinely recommend bed rest (95% confidence interval [CI], 84.7-97.2). In all, 82% (95% CI, 73.63-90.4%) recommended routine cervical length assessment with 32.3% (95% CI, 20.7-43.2) and 37.1% (95% CI, 25.3-48.6) of this group suggesting assessment at 16-18 and 19-21 weeks, respectively. Frequency of assessment varied from biweekly (53.3%; 95% CI, 40.9-65.0), to monthly (23.3%; 95% CI, 12.8-33.1), to a single measurement repeated only if abnormal (12.5%; 95% CI, 4.5-20.8). In all, 28% (95% CI, 18.2-37.8) recommended routine administration of corticosteroids for lung maturation. Timing of administration varied, with 24% initiating steroids between 24-26 weeks, 59% between 27-28 weeks, and 17% after 28 weeks. None reported routine cerclage placement. However, 71% (95% CI, 61.1-80.8) would perform cerclage based on history or ultrasound. Of respondents, 81% (95% CI, 72.4-89.5) would consider using tocolytic agents for threatened preterm labor including calcium channel blockers (94%), nonsteroidal antiinflammatory drugs (5%), and nitroglycerin transdermal patch (24%). CONCLUSION: The variable practice guidelines and paucity of data for management of HOM pregnancy places the onus on individual practitioners to develop their own management schemes. This results in heterogeneous management, which is based on conflicting international guidelines, studies, expert opinion, or past experience.

Prospective study of intracranial translucency and the posterior brain in normal fetuses at the 11- to 13-week scan.

OBJECTIVES: To evaluate the ability of sonographers to prospectively identify intracranial translucency and posterior brain structures at 11 to 13 weeks and to evaluate measurement reproducibility of brain stem and brain stem-occipital bone diameters on stored images. METHODS: After specific training for intracranial translucency visualization, 10 nonphysician sonographers prospectively identified intracranial translucency at the 11- to 13-week scan, noting whether intracranial translucency was present, absent, or uncertain. If absent/uncertain, they documented the reason as spina bifida or an inadequate image (with reasons for the inadequate image). Measurements of brain stem and brain stem-occipital bone diameters were performed on stored images. Fifty randomly selected cases were reviewed for intraobserver and interobserver variability. RESULTS: In 313 singleton pregnancies, the posterior brain including intracranial translucency was evaluated; 293 (93.6%) had known pregnancy outcomes. None had open spina bifida, but 7 had chromosomal or congenital abnormalities. In the remaining 286 normal fetuses, intracranial translucency was seen in 275 (96%) and uncertain in 11 (4%), due to inadequate images (top 3 reasons were fetal position [n = 8], obesity [n = 5], and retroverted uterus [n = 4]). Fetal position and gestational age were significantly associated with intracranial translucency visualization (P < .05). Intraobserver and interobserver agreement rates were moderate for measurements of brain stem diameter (intraclass correlation coefficients, 0.59 and 0.57) and substantial for brain stem-occipital bone diameter (intraclass correlation coefficients, 0.76 and 0.61). Bland-Altman analysis revealed negligible intraobserver and interobserver differences in brain stem and brain stem-occipital bone diameter measurements. CONCLUSIONS: Intracranial translucency can be prospectively identified by trained sonographers in 96% of normal fetuses at 11 to 13 weeks. Measurements of brain stem and brain stem-occipital bone diameters are reproducible.

Pregnancy outcomes after assisted human reproduction.

OBJECTIVE: To review the effect of assisted human reproduction (AHR) on perinatal outcomes, to identify areas requiring further research with regard to birth outcomes and AHR, and to provide guidelines to optimize obstetrical management and counselling of prospective Canadian parents. OUTCOMES: This document compares perinatal outcomes of different types of AHR pregnancies with each other and with those of spontaneously conceived pregnancies. Clinicians will be better informed about the adverse outcomes that have been documented in association with AHR, including obstetrical complications, adverse perinatal outcomes, multiple gestations, structural congenital abnormalities, chromosomal abnormalities, and imprinting disorders. EVIDENCE: Published literature was retrieved through searches of MEDLINE and the Cochrane Library from January 2005 to December 2012 using appropriate controlled vocabulary and key words (assisted reproduction, assisted reproductive technology, ovulation induction, intracytoplasmic sperm injection, embryo transfer, and in vitro fertilization). Results were not restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies; studies of all designs published in English from January 2005 to December 2012 were reviewed, and additional publications were identified from the bibliographies of these articles. Searches were updated on a regular basis and incorporated in the guideline to August 2013. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. VALUES: The quality of evidence in this document was rated using the criteria described in the Report of the Canadian Task Force on Preventive Health Care (Table 1). Summary Statements 1. There is increasing evidence that infertility or subfertility is an independent risk factor for obstetrical complications and adverse perinatal outcomes, even without the addition of assisted human reproduction. (II-2) 2. The relative risk for an imprinting phenotype such as Silver-Russell syndrome, Beckwith-Wiedemann syndrome, or Angelman syndrome is increased in the assisted reproduction population, but the actual risk for one of these phenotypes to occur in an assisted pregnancy is estimated to be low, at less than 1 in 5000. The exact biological etiology for this increased imprinting risk is likely heterogeneous and requires more research. (II-2) Recommendations 1. All men with severe oligozoospermia or azoospermia (sperm count < 5 million/hpf) should be offered genetic/clinical counselling, karyotype assessment for chromosomal abnormalities, and Y-chromosome microdeletion testing prior to in vitro fertilization with intracytoplasmic sperm injection. (II-2A) 2. All men with unexplained obstructive azoospermia should be offered genetic/clinical counselling and genetic testing for cystic fibrosis prior to in vitro fertilization with intracytoplasmic sperm injection. (II-2A) 3. Multiple pregnancy is the most powerful predictive factor for adverse maternal, obstetrical, and perinatal outcomes. Couples should be thoroughly counselled about the significant risks of multiple pregnancies associated with all assisted human reproductive treatments. (II-2A) 4. The benefits and cumulative pregnancy rates of elective single embryo transfer support a policy of using this protocol in couples with good prognosis for success, and elective single embryo transfer should be strongly encouraged in this population. (II-2A) 5. To reduce the incidence of multiple pregnancy, health care policies that support public funding for assisted human reproduction, with regulations promoting best practice regarding elective single embryo transfer, should be strongly encouraged. (II-2A) 6. Among singleton pregnancies, assisted reproductive technology is associated with increased risks of preterm birth and low birth weight infants, and ovulation induction is associated with an increased risk of low birth weight infants. Until sufficient research has clarified the independent roles of infertility and treatment for infertility, couples should be counselled about the risks associated with treatment. (II-2B) There is a role for closer obstetric surveillance of women who conceive with assisted human reproduction. (III-L) 7. There is growing evidence that pregnancy outcomes are better for cryopreserved embryos fertilized in vitro than for fresh embryo transfers. This finding supports a policy of elective single embryo transfer for women with a good prognosis (with subsequent use of cryopreserved embryos as necessary), and may reassure women who are considering in vitro fertilization. (II-2A) 8. Women and couples considering assisted human reproduction and concerned about perinatal outcomes in singleton pregnancies should be advised that (1) intracytoplasmic sperm injection does not appear to confer increased adverse perinatal or maternal risk over standard in vitro fertilization, and (2) the use of donor oocytes increases successful pregnancy rates in selected women, but even when accounting for maternal age, can increase the risks of low birth weight and preeclampsia. (II-2B) 9. Any assisted reproductive technology procedure should be prefaced by a discussion of fetal outcomes and the slight increase in the risk of congenital structural abnormalities, with emphasis on known confounding factors such as infertility and body mass index. (II-2B) 10. In pregnancies achieved by artificial reproductive technology, routine anatomic ultrasound for congenital structural abnormalities is recommended between 18 and 22 weeks. (II-2A) 11. Pregnancies conceived by intracytoplasmic sperm injection may be at increased risk of chromosomal aberrations, including sex chromosome abnormalities. Diagnostic testing should be offered after appropriate counselling. (II-2A) 12. The possible increased risk for late onset cancer due to gene dysregulation for tumour suppression requires more long-term follow-up before the true risk can be determined. (III-A) 13. The clinical application of preimplantation genetic testing in fertile couples must balance the benefits of avoiding disease transmission with the medical risks and financial burden of in vitro fertilization. (III-B) 14. Preimplantation screening for aneuploidy is associated with inconsistent findings for improving pregnancy outcomes. Any discussion of preimplantation genetic screening with patients should clarify that there is no adequate information on the long-term effect of embryo single cell biopsy. (I-C).

Objectif : Analyser l'effet du recours à la procréation assistée (PA) sur les issues périnatales, identifier les aspects propres aux issues de naissance et à la PA qui nécessitent des recherches approfondies, et fournir des lignes directrices permettant l'optimisation de la prise en charge obstétricale et du counseling des parents potentiels canadiens. Issues : Le présent document compare les issues périnatales constatées dans le cadre de différents types de grossesse attribuable à la PA les unes aux autres, ainsi qu'à celles qui sont constatées dans le cadre des grossesses conçues de façon spontanée. Les cliniciens seront mieux renseignés au sujet des issues indésirables associées à la PA qui ont été documentées, y compris les complications obstétricales, les issues périnatales indésirables, les gestations multiples, les anomalies congénitales structurelles, les anomalies chromosomiques et les troubles de l'empreinte génomique. Résultats : La littérature publiée a été récupérée par l'intermédiaire de recherches menées dans MEDLINE et The Cochrane Library entre janvier 2005 et décembre 2012 au moyen d'un vocabulaire contrôlé et de mots clés appropriés (« assisted reproduction ¼, « assisted reproductive technology ¼, « ovulation induction ¼, « intracytoplasmic sperm injection ¼, « embryo transfer ¼ et « in vitro fertilization ¼). Les résultats n'ont pas été restreints aux analyses systématiques, aux essais comparatifs randomisés / essais cliniques comparatifs et aux études observationnelles; les études (tous devis confondus) publiées en anglais entre janvier 2005 et décembre 2012 ont été analysées, et des publications additionnelles ont été identifiées à partir des bibliographies de ces études. Les recherches ont été mises à jour de façon régulière et intégrées à la directive clinique jusqu'en août 2013. La littérature grise (non publiée) a été identifiée par l'intermédiaire de recherches menées dans les sites Web d'organismes s'intéressant à l'évaluation des technologies dans le domaine de la santé et d'organismes connexes, dans des collections de directives cliniques, dans des registres d'essais cliniques et auprès de sociétés de spécialité médicale nationales et internationales. Valeurs : La qualité des résultats est évaluée au moyen des critères décrits dans le rapport du Groupe d'étude canadien sur les soins de santé préventifs (Tableau). Déclarations sommaires 1. De plus en plus de données indiquent que l'infertilité ou l'hypofertilité constitue un facteur de risque indépendant en ce qui concerne les complications obstétricales et les issues périnatales indésirables, même sans l'ajout de la procréation assistée. (II-2) 2. Bien que le risque relatif de voir apparaître un phénotype d'empreinte génomique (comme le syndrome de Silver-Russell, le syndrome de Beckwith-Wiedemann ou le syndrome d'Angelman) soit accru au sein de la population issue de la procréation assistée, on estime que le risque réel de voir apparaître un de ces phénotypes dans le cadre d'une grossesse attribuable à la procréation assistée est faible (inférieur à 1 sur 5 000). L'étiologie biologique exacte de cette hausse du risque lié à l'empreinte génomique est probablement hétérogène et nécessite la tenue d'autres recherches. (II-2) Recommandations 1. Tous les hommes qui présentent une oligozoospermie ou une azoospermie graves (numération de spermatozoïdes < 5 millions/hpf) devraient se voir offrir des services de counseling génétique / clinique, une évaluation du caryotype visant les anomalies chromosomiques et un dépistage des microdélétions du chromosome Y avant la tenue d'une fécondation in vitro-injection intracytoplasmique d'un spermatozoïde. (II-2A) 2. Tous les hommes qui présentent une azoospermie obstructive inexpliquée devraient se voir offrir des services de counseling génétique / clinique et un dépistage génétique visant la fibrose kystique avant la tenue d'une fécondation in vitro-injection intracytoplasmique d'un spermatozoïde. (II-2) 3. La grossesse multiple constitue le facteur prédictif le plus puissant en ce qui concerne les issues indésirables maternelles, obstétricales et périnatales. Les couples devraient bénéficier de services de counseling exhaustifs au sujet des risques importants que posent les grossesses multiples associées aux traitements de procréation assistée, tous types confondus. (II-2A) 4. Les avantages et les taux cumulatifs de grossesse associés au transfert sélectif d'un seul embryon soutiennent la mise en œuvre d'une politique en instaurant l'utilisation chez les couples qui présentent un bon pronostic de réussite; le recours au transfert sélectif d'un seul embryon devrait être fortement encouragé chez cette population. (II-2) 5. Pour réduire l'incidence de la grossesse multiple, la mise en œuvre de politiques de santé soutenant le financement public de la procréation assistée (le tout s'accompagnant de règlements faisant la promotion de l'adoption de pratiques optimales à l'égard du transfert sélectif d'un seul embryon) devrait être fortement encouragée. (II-2A) 6. Dans le cas des grossesses monofœtales, les techniques de procréation assistée sont associées à un risque accru de connaître un accouchement préterme et d'obtenir un enfant présentant un faible poids de naissance, et le déclenchement de l'ovulation est associé à un risque accru d'obtenir un enfant présentant un faible poids de naissance. Jusqu'à ce qu'un nombre suffisant de recherches aient été menées pour clarifier les rôles indépendants de l'infertilité et des traitements contre l'infertilité, les couples devraient bénéficier de services de counseling au sujet des risques associés au traitement. (II-2B) La mise en œuvre d'une surveillance obstétricale plus étroite a un rôle à jouer dans la prise en charge des femmes qui ont recours à la procréation assistée. (III-L) 7. De plus en plus de données indiquent que les issues de grossesse sont meilleures lorsque l'on a recours au transfert d'embryons fécondés in vitro, puis cryoconservés, plutôt qu'au transfert d'embryons frais. Cette constatation soutient la mise en œuvre d'une politique instaurant l'utilisation du transfert sélectif d'un seul embryon chez les couples qui présentent un bon pronostic de réussite (suivie de l'utilisation d'embryons cryoconservés, au besoin) et pourrait rassurer les femmes qui envisagent d'avoir recours à la fécondation in vitro. (II-2A) 8. Les femmes et les couples qui envisagent d'avoir recours à la procréation assistée, et qui entretiennent des préoccupations au sujet des issues périnatales associées aux grossesses monofœtales devraient être avisés que (1) l'injection intracytoplasmique d'un spermatozoïde ne semble pas donner lieu à une hausse du risque maternel ou du risque d'obtenir des issues périnatales indésirables, par comparaison avec la fécondation in vitro standard, et que (2) le recours à des ovocytes issus de donatrices entraîne la hausse des taux de grossesse réussie chez certaines femmes, mais qu'il peut également accroître le risque de faible poids de naissance et de prééclampsie, même en tenant compte de l'âge maternel. (II-2B) 9. Le recours à toute intervention faisant appel aux techniques de procréation assistée devrait être précédé d'une discussion sur les issues fœtales et la légère hausse du risque d'anomalies congénitales structurelles, en s'assurant de mettre l'accent sur les facteurs de confusion connus (tels que l'infertilité et l'indice de masse corporelle). (II-2B) 10. Dans le cas des grossesses attribuables aux techniques de procréation assistée, la tenue systématique d'une échographie anatomique visant les anomalies congénitales structurelles est recommandée entre 18 et 22 semaines. (II-2A) 11. Les grossesses attribuables à l'injection intracytoplasmique d'un spermatozoïde pourraient être exposées à un risque accru d'aberrations chromosomiques, y compris des anomalies affectant les chromosomes sexuels. Des tests diagnostiques devraient être offerts à la suite de l'offre de services de counseling appropriés. (II-2A) 12. La hausse possible du risque de cancer d'apparition tardive attribuable à la dysrégulation génique de la suppression tumorale nécessite la mise en œuvre d'un suivi à plus long terme, et ce, jusqu'à ce que le risque réel puisse être déterminé. (III-A) 13. La mise en œuvre clinique du dépistage génétique préimplantatoire chez les couples fertiles doit mettre en balance les avantages du fait d'éviter la transmission de pathologies et les risques médicaux (et le fardeau financier) de la fécondation in vitro. (III-B) 14. Le dépistage préimplantatoire de l'aneuploïdie est associé à des constatations hétérogènes pour ce qui est de l'amélioration des issues de grossesse. Toute discussion avec les patientes au sujet du dépistage génétique préimplantatoire devrait mettre au clair que nous ne disposons pas de renseignements adéquats quant aux effets à long terme de la biopsie unicellulaire de l'embryon. (I-C).

Prediction of adverse pregnancy outcomes by combinations of first and second trimester biochemistry markers used in the routine prenatal screening of Down syndrome.

OBJECTIVE: To investigate the associations between four defined adverse pregnancy outcomes and levels of first and second trimester maternal serum markers focusing in particular on how well combinations of markers predict these adverse outcomes. METHODS: This was a retrospective review of associations between first and second trimester serum markers and adverse pregnancy outcomes among 141 698 women who underwent prenatal screening for Down syndrome in Ontario, Canada. Detection rates (DR), false positive rates (FPR), and odds ratios were estimated using both single and combinations of markers for the adverse outcomes defined. RESULTS: Women with decreased second trimester unconjugated oestriol (uE3), deceased first trimester maternal serum pregnancy-associated plasma protein A (PAPP-A), increased second trimester serum alpha fetoprotein (AFP), or increased second trimester total human chorionic gonadotrophin (hCG) were at greater risk of developing adverse pregnancy outcomes. At a 5% FPR, combinations of these markers predicted at best 33.3% of fetal loss and 31.5% of preterm births (PTB) before 32 weeks of gestation. CONCLUSION: There are significant associations between the levels of first and second trimester serum markers and adverse obstetric outcomes. However, even combinations of these markers can only predict adverse obstetric outcomes with modest accuracy.

Prospective experience with integrated prenatal screening and first trimester combined screening for trisomy 21 in a large Canadian urban center.

OBJECTIVES: To evaluate the performance of integrated prenatal screening (IPS) and first trimester combined screening (FTS) for trisomy 21 in a large Canadian urban center. METHOD: Prospective data collection on women having FTS at one center from 1 November 2003 to 31 December 2005, or IPS at another from 1 January 2003 to 31 December 2005. A positive screen was defined as adjusted risk for trisomy 21 >or= 1/200 at term or nuchal translucency >or= 3.5 mm. RESULTS: 32 227 and 14 487 women were screened in the IPS and FTS programs, respectively. Detection rates (DRs) and positive rates (PRs) for trisomy 21 were 88.4% (95% CI: 81.6-91.5) and 3.3% (95% CI: 3.1-3.5) for IPS, and 83.9% (95% CI: 74.7-93.0) and 4.0% (95% CI: 3.7-4.3) for FTS. DR adjusted for viability bias was 85.2% for IPS and 78.6% for FTS. Applying both the screens to the 78 134 women who submitted prenatal screens in Ontario in 2005, thereby eliminating the effect of differences in the distribution of maternal age between screens, gave a DR (corrected for viability bias) and PR of 81 and 3.1% for IPS, and 76 and 3.4% for FTS. CONCLUSIONS: Both IPS and FTS perform well and are feasible in a practical clinical setting.