Cerebroplacental ratio in predicting adverse perinatal outcome: a meta-analysis of individual participant data.

OBJECTIVE: To investigate if cerebroplacental ratio (CPR) adds to the predictive value of umbilical artery pulsatility index (UA PI) alone - standard of practice - for adverse perinatal outcome in singleton pregnancies. DESIGN AND SETTING: Meta-analysis based on individual participant data (IPD). POPULATION OR SAMPLE: Ten centres provided 17 data sets for 21 661 participants, 18 731 of which could be included. Sample sizes per data set ranged from 207 to 9215 individuals. Patient populations varied from uncomplicated to complicated pregnancies. METHODS: In a collaborative, pooled analysis, we compared the prognostic value of combining CPR with UA PI, versus UA PI only and CPR only, with a one-stage IPD approach. After multiple imputation of missing values, we used multilevel multivariable logistic regression to develop prediction models. We evaluated the classification performance of all models with receiver operating characteristics analysis. We performed subgroup analyses according to gestational age, birthweight centile and estimated fetal weight centile. MAIN OUTCOME MEASURES: Composite adverse perinatal outcome, defined as perinatal death, caesarean section for fetal distress or neonatal unit admission. RESULTS: Adverse outcomes occurred in 3423 (18%) participants. The model with UA PI alone resulted in an area under the curve (AUC) of 0.775 (95% CI 0.709-0.828) and with CPR alone in an AUC of 0.778 (95% CI 0.715-0.831). Addition of CPR to the UA PI model resulted in an increase in the AUC of 0.003 points (0.778, 95% CI 0.714-0.831). These results were consistent across all subgroups. CONCLUSIONS: Cerebroplacental ratio added no predictive value for adverse perinatal outcome beyond UA PI, when assessing singleton pregnancies, irrespective of gestational age or fetal size. TWEETABLE ABSTRACT: Doppler measurement of cerebroplacental ratio in clinical practice has limited added predictive value to umbilical artery alone.

Fetal megacystis: a lot more than LUTO.

OBJECTIVE: Fetal megacystis presents a challenge in terms of counseling and management because of its varied etiology and evolution. The aim of this study was to present a comprehensive overview of the underlying etiologies and structural anomalies associated with fetal megacystis. METHODS: This was a retrospective multicenter study of cases referred to the fetal medicine unit of one of the eight academic hospitals in The Netherlands with a diagnosis of fetal megacystis. For each case, data on and measurements of fetal urinary tract and associated structural anomalies were collected. All available postmortem examinations and postnatal investigations were reviewed in order to establish the final diagnosis. In the first trimester, fetal megacystis was defined as longitudinal bladder diameter (LBD) ≥ 7 mm, and in the second and third trimesters as an enlarged bladder failing to empty during an extended ultrasound examination lasting at least 40 min. RESULTS: Of the 541 pregnancies with fetal megacystis, it was isolated (or solely accompanied by other signs of lower urinary tract obstruction (LUTO)) in 360 (67%) cases and associated with other abnormal ultrasound findings in 181 (33%) cases. The most common associated ultrasound anomaly was an increased nuchal translucency thickness (22%), followed by single umbilical artery (10%) and cardiac defect (10%). A final diagnosis was established in 418 cases, including 222 (53%) cases with isolated LUTO and 60 (14%) infants with normal micturition or minor isolated urological anomalies. In the remaining 136 (33%) cases, concomitant developmental or chromosomal abnormality or genetic syndrome was diagnosed. Overall, 40 chromosomal abnormalities were diagnosed, including trisomy 18 (n = 24), trisomy 21 (n = 5), Turner syndrome (n = 5), trisomy 13 (n = 3) and 22q11 deletion (n = 3). Thirty-two cases presented with anorectal malformations involving the anus, rectum and urogenital tract. In cases with confirmed urethral and anal atresia, megacystis occurred early in pregnancy and the bladder appeared severely distended (the LBD (in mm) was equal to or greater than twice the gestational age (in weeks)). Fetal macrosomia was detected in six cases and an overgrowth syndrome was detected in four cases, comprising two infants with Beckwith-Wiedemann syndrome and two with Sotos syndrome. Megacystis-microcolon-intestinal hypoperistalsis syndrome was diagnosed in five (1%) cases and prenatally suspected only in one case. CONCLUSIONS: Although the main cause of fetal megacystis is LUTO, an enlarged fetal bladder can also be present as a concomitant finding of miscellaneous genetic syndromes, developmental disturbances and chromosomal abnormalities. We provide an overview of the structural anomalies and congenital disorders associated with fetal megacystis and propose a practical guide for the differential diagnosis of genetic syndromes and chromosomal and developmental abnormalities in pregnancies presenting with fetal megacystis, focusing on the morphological examination of the fetus. © 2018 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Cost-effectiveness of diagnostic testing strategies including cervical-length measurement and fibronectin testing in women with symptoms of preterm labor.

OBJECTIVE: To evaluate the cost-effectiveness of combining cervical-length (CL) measurement and fetal fibronectin (fFN) testing in women with symptoms of preterm labor between 24 and 34 weeks' gestation. METHODS: This was a model-based cost-effectiveness analysis evaluating seven test-treatment strategies based on CL measurement and/or fFN testing in women with symptoms of preterm labor from a societal perspective, in which neonatal outcomes and costs were weighted. Estimates of disease prevalence, test accuracy and costs were based on two recently performed nationwide cohort studies in The Netherlands. RESULTS: Strategies using fFN testing and CL measurement separately to predict preterm delivery are associated with higher costs and incidence of adverse neonatal outcomes compared with strategies that combine both tests. Additional fFN testing when CL is 15-30 mm was considered cost effective, leading to a cost saving of €3919 per woman when compared with a treat-all strategy, with a small deterioration in neonatal health outcomes, namely one additional perinatal death and 21 adverse outcomes per 10 000 women with signs of preterm labor (incremental cost-effectiveness ratios €39 million and €1.9 million, respectively). Implementing this strategy in The Netherlands, a country with about 180 000 deliveries annually, could lead to an annual cost saving of between €2.4 million and €7.6 million, with only a small deterioration in neonatal health outcomes. CONCLUSION: In women with symptoms of preterm labor at 24-34 weeks' gestation, performing additional fFN testing when CL is between 15 and 30 mm is a viable and cost-saving strategy. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

Prenatal diagnosis of LUTO: improving diagnostic accuracy.

OBJECTIVE: To propose a clinical score for the optimal antenatal diagnosis of fetal lower urinary tract obstruction (LUTO) in the second and third trimesters of pregnancy, as an alternative to the commonly used ultrasound triad of megacystis, keyhole sign and hydronephrosis. METHODS: This was a national retrospective study carried out at the eight tertiary fetal medicine units (FMUs) in The Netherlands. Only cases referred for megacystis from the second trimester onwards and with a clear postnatal diagnosis were included in the study. At referral, data were collected on amniotic fluid volume, renal cortical appearance, bladder volume, hydronephrosis, fetal ascites, ureteral size, keyhole sign, fetal sex and gestational age. Multivariate analysis was performed, starting by including all antenatal variables, and then excluding the weakest predictors using the backward stepwise strategy. RESULTS: Over a 7-year period, 312 fetuses with a diagnosis of megacystis were referred to the eight Dutch tertiary FMUs. A final diagnosis was achieved in 143 cases, including 124 of LUTO and 19 reclassified after birth as non-obstructive megacystis. The optimal bladder volume cut-off for prediction of LUTO was 35 cm3 (area under the curve (AUC) = 0.7, P = 0.03). The clinical score formulated on the basis of the multivariate analysis included fetal sex, degree of bladder distension, ureteral size, oligo- or anhydramnios and gestational age at referral. The combination of these five variables demonstrated good accuracy in discriminating LUTO from non-obstructive megacystis (AUC = 0.84, P < 0.001), compared with the poor performance of the ultrasound triad (AUC = 0.63, P = 0.07). CONCLUSIONS: We propose a clinical score that combines five antenatal variables for the prospective diagnosis of congenital LUTO. This score showed good discriminative capacity in predicting LUTO, and better diagnostic accuracy compared with that of the classic ultrasound triad. Future studies to validate these results should be carried out in order to refine antenatal management of LUTO and prevent inappropriate fetal interventions. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Prognostic accuracy of cerebroplacental ratio and middle cerebral artery Doppler for adverse perinatal outcome: systematic review and meta-analysis.

OBJECTIVE: Doppler ultrasonographic assessment of the cerebroplacental ratio (CPR) and middle cerebral artery (MCA) is widely used as an adjunct to umbilical artery (UA) Doppler to identify fetuses at risk of adverse perinatal outcome. However, reported estimates of its accuracy vary considerably. The aim of this study was to review systematically the prognostic accuracies of CPR and MCA Doppler in predicting adverse perinatal outcome, and to compare these with UA Doppler, in order to identify whether CPR and MCA Doppler evaluation are of added value to UA Doppler. METHODS: PubMed, EMBASE, the Cochrane Library and ClinicalTrials.gov were searched, from inception to June 2016, for studies on the prognostic accuracy of UA Doppler compared with CPR and/or MCA Doppler in the prediction of adverse perinatal outcome in women with a singleton pregnancy of any risk profile. Risk of bias and concerns about applicability were assessed using the QUADAS-2 (Quality Assessment of Diagnostic Accuracy Studies-2) tool. Meta-analysis was performed for multiple adverse perinatal outcomes. Using hierarchal summary receiver-operating characteristics meta-regression models, the prognostic accuracy of CPR vs MCA Doppler was compared indirectly, and CPR and MCA Doppler vs UA Doppler compared directly. RESULTS: The search identified 4693 articles, of which 128 studies (involving 47 748 women) were included. Risk of bias or suboptimal reporting was detected in 120/128 studies (94%) and substantial heterogeneity was found, which limited subgroup analyses for fetal growth and gestational age. A large variation was observed in reported sensitivities and specificities, and in thresholds used. CPR outperformed UA Doppler in the prediction of composite adverse outcome (as defined in the included studies) (P < 0.001) and emergency delivery for fetal distress (P = 0.003), but was comparable to UA Doppler for the other outcomes. MCA Doppler performed significantly worse than did UA Doppler in the prediction of low Apgar score (P = 0.017) and emergency delivery for fetal distress (P = 0.034). CPR outperformed MCA Doppler in the prediction of composite adverse outcome (P < 0.001) and emergency delivery for fetal distress (P = 0.013). CONCLUSION: Calculating the CPR with MCA Doppler can add value to UA Doppler assessment in the prediction of adverse perinatal outcome in women with a singleton pregnancy. However, it is unclear to which subgroup of pregnant women this applies. The effectiveness of the CPR in guiding clinical management needs to be evaluated in clinical trials. © 2017 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of the International Society of Ultrasound in Obstetrics and Gynecology.

Fetal megacystis: prediction of spontaneous resolution and outcome.

OBJECTIVES: To investigate the natural history of fetal megacystis from diagnosis in utero to postnatal outcome, and to identify prognostic indicators of spontaneous resolution and postnatal outcome after resolution. METHODS: This was a national retrospective cohort study. Fetal megacystis was defined in the first trimester as a longitudinal bladder diameter (LBD) ≥ 7 mm, and in the second and third trimesters as an enlarged bladder failing to empty during the entire extended ultrasound examination. LBD and gestational age (GA) at resolution were investigated with respect to likelihood of resolution and postnatal outcome, respectively. Sensitivity, specificity and area under the receiver-operating characteristics curve (AUC) were calculated. RESULTS: In total, 284 cases of fetal megacystis (93 early megacystis, identified before the 18th week, and 191 late megacystis, identified at or after the 18th week) were available for analysis. Spontaneous resolution occurred before birth in 58 (20%) cases. In cases with early megacystis, LBD was predictive of the likelihood of spontaneous resolution (sensitivity, 80%; specificity, 79%; AUC, 0.84), and, in the whole population, GA at regression was predictive of postnatal outcome, with an optimal cut-off at 23 weeks (sensitivity, 100%; specificity, 82%; AUC, 0.91). In the group with early megacystis, the outcome was invariably good when resolution occurred before the 23rd week of gestation, whereas urological sequelae requiring postnatal surgery were diagnosed in 3/8 (38%) cases with resolution after 23 weeks. In the group with late megacystis, spontaneous resolution was associated with urological complications after birth, ranging from mild postnatal hydronephrosis in infants with resolution before 23 weeks, to more severe urological anomalies requiring postnatal surgery in those with resolution later in pregnancy. This supports the hypothesis that an early resolution of megacystis is often related to a paraphysiological bladder enlargement that resolves early in pregnancy without consequences, while antenatal resolution occurring later in pregnancy (after the 23rd week of gestation) should suggest a pathological condition with urological sequelae. CONCLUSIONS: In fetal megacystis, LBD and GA at regression can be used as predictors of resolution and outcome, respectively. These parameters could help in fine-tuning the prognosis and optimizing the frequency of follow-up scans. Copyright © 2017 ISUOG. Published by John Wiley & Sons Ltd.

A Randomised Controlled Trial of Consent Procedures for the Use of Residual Tissues for Medical Research: Preferences of and Implications for Patients, Research and Clinical Practice.

BACKGROUND: Despite much debate, there is little evidence on consequences of consent procedures for residual tissue use. Here, we investigated these consequences for the availability of residual tissue for medical research, clinical practice, and patient informedness. METHODS: We conducted a randomised clinical trial with three arms in six hospitals. Participants, patients from whom tissue had been removed for diagnosis or treatment, were randomised to one of three arms: informed consent, an opt-out procedure with active information provision (opt-out plus), and an opt-out procedure without active information provision. Participants received a questionnaire six weeks post-intervention; a subsample of respondents was interviewed. Health care providers completed a pre- and post-intervention questionnaire. We assessed percentage of residual tissue samples available for medical research, and patient and health care provider satisfaction and preference. Health care providers and outcome assessors could not be blinded. RESULTS: We randomised 1,319 patients, 440 in the informed consent, 434 in the opt-out plus, and 445 in the opt-out arm; respectively 60.7%, 100%, and 99.8% of patients' tissue samples could be used for medical research. Of the questionnaire respondents (N = 224, 207, and 214 in the informed consent, opt-out plus, and opt-out arms), 71%, 69%, and 31%, respectively, indicated being (very) well informed. By questionnaire, the majority (53%) indicated a preference for informed consent, whereas by interview, most indicated a preference for opt-out plus (37%). Health care providers (N = 35) were more likely to be (very) satisfied with opt-out plus than with informed consent (p = 0.002) or opt-out (p = 0.039); the majority (66%) preferred opt-out plus. CONCLUSION: We conclude that opt-out with information (opt-out plus) is the best choice to balance the consequences for medical research, patients, and clinical practice, and is therefore the most optimal consent procedure for residual tissue use in Dutch hospitals. TRIAL REGISTRATION: Dutch Trial Register NTR2982.

Prenatal diagnosis of congenital heart defects: accuracy and discrepancies in a multicenter cohort.

OBJECTIVE: To examine the accuracy of fetal echocardiography in diagnosing congenital heart disease (CHD) at the fetal medicine units of three tertiary care centers. METHODS: This was a multicenter cohort study of tertiary echocardiography referrals between 2002 and 2012. Prenatal and postnatal diagnoses were compared and the degree of agreement was classified as 'correct' (anatomy correct and the postnatal diagnosis led to a similar outcome as expected), 'discrepant' (anatomical discrepancies present but the severity and prognosis of the defect were diagnosed correctly) or 'no similarity' (the pre- and postnatal diagnoses differed completely). RESULTS: We included 708 cases with CHD for which both prenatal and postnatal data were available. The prenatal diagnosis was correct in 82.1% of cases and discrepancies present were present in 9.9%; however, these did not result in a different outcome. In 8.1% there was no similarity between prenatal and postnatal diagnoses. Disagreement between pre- and postnatal diagnoses occurred significantly more frequently in cases that presented with a normal four-chamber view than in those with an abnormal four-chamber view (5.5% vs 1.9%). Incorrect identification of the outflow tracts and incorrect differentiation between unbalanced atrioventricular septal defect and hypoplastic left heart syndrome were relatively commonly encountered. In many cases with disagreement, trisomy 21, extracardiac anomaly or a high maternal body mass index was present. CONCLUSIONS: The prenatal diagnosis and estimated prognosis of fetal echocardiography in our tertiary referral centers were appropriate in 92% of cases. Some types of CHD remain difficult to diagnose or rule-out prenatally, therefore awareness and education are of considerable importance. Copyright © 2015 ISUOG. Published by John Wiley & Sons Ltd.

Quantitative fetal fibronectin testing in combination with cervical length measurement in the prediction of spontaneous preterm delivery in symptomatic women.

OBJECTIVE: To evaluate whether in symptomatic women, the combination of quantitative fetal fibronectin (fFN) testing and cervical length (CL) improves the prediction of preterm delivery (PTD) within 7 days compared with qualitative fFN and CL. DESIGN: Post hoc analysis of frozen fFN samples of a nationwide cohort study. SETTING: Ten perinatal centres in the Netherlands. POPULATION: Symptomatic women between 24 and 34 weeks of gestation. METHODS: The risk of PTD <7 days was estimated in predefined CL and fFN strata. We used logistic regression to develop a model including quantitative fFN and CL, and one including qualitative fFN (threshold 50 ng/ml) and CL. We compared the models' capacity to identify women at low risk (<5%) for delivery within 7 days using a reclassification table. MAIN OUTCOME MEASURES: Spontaneous delivery within 7 days after study entry. RESULTS: We studied 350 women, of whom 69 (20%) delivered within 7 days. The risk of PTD in <7 days ranged from 2% in the lowest fFN group (<10 ng/ml) to 71% in the highest group (>500 ng/ml). Multivariable logistic regression showed an increasing risk of PTD in <7 days with rising fFN concentration [10-49 ng/ml: odds ratio (OR) 1.3, 95% confidence interval (95% CI) 0.23-7.0; 50-199 ng/ml: OR 3.2, 95% CI 0.79-13; 200-499 ng/ml: OR 9.0, 95% CI 2.3-35; >500 ng/ml: OR 39, 95% CI 9.4-164] and shortening of the CL (OR 0.86 per mm, 95% CI 0.82-0.90). Use of quantitative fFN instead of qualitative fFN resulted in reclassification of 18 (5%) women from high to low risk, of whom one (6%) woman delivered within 7 days. CONCLUSION: In symptomatic women, quantitative fFN testing does not improve the prediction of PTD within 7 days compared with qualitative fFN testing in combination with CL measurement in terms of reclassification from high to low (<5%) risk, but it adds value across the risk range. TWEETABLE ABSTRACT: Quantitative fFN testing adds value to qualitative fFN testing with CL measurement in the prediction of PTD.

Prenatal detection of congenital heart disease--results of a national screening programme.

OBJECTIVE: Congenital heart disease (CHD) is the most common congenital malformation and causes major morbidity and mortality. Prenatal detection improves the neonatal condition before surgery, resulting in less morbidity and mortality. In the Netherlands a national prenatal screening programme was introduced in 2007. This study evaluates the effects of this screening programme. DESIGN: Geographical cohort study. SETTING: Large referral region of three tertiary care centres. POPULATION: Fetuses and infants diagnosed with severe CHD born between 1 January 2002 and 1 January 2012. METHODS: Cases were divided into two groups: before and after the introduction of screening. MAIN OUTCOME MEASURES: Detection rates were calculated. RESULTS: The prenatal detection rate (n = 1912) increased with 23.9% (95% confidence interval [95% CI] 19.5-28.3) from 35.8 to 59.7% after the introduction of screening and of isolated CHD with 21.4% (95% CI 16.0-26.8) from 22.8 to 44.2%. The highest detection rates were found in the hypoplastic left heart syndrome, other univentricular defects and complex defects with atrial isomerism (>93%). Since the introduction of screening, the 'late' referrals (after 24 weeks of gestation) decreased by 24.3% (95% CI 19.3-29.3). CONCLUSIONS: This is the largest cohort study to investigate the prenatal detection rate of severe CHD in an unselected population. A nationally organised screening has resulted in a remarkably high detection rate of CHD (59.7%) compared with earlier literature.

Prenatal detection of transposition of the great arteries reduces mortality and morbidity.

OBJECTIVES: To evaluate the prenatal detection of transposition of the great arteries (TGA), after the introduction of a Dutch screening program in 2007, as well as the effect of prenatal detection on pre- and postsurgical mortality and morbidity. METHODS: In a geographical cohort study, all infants with TGA who were born between 1 January 2002 and 1 January 2012 were included. The cases were divided into two groups: those with and those without a prenatal diagnosis. Pre- and postsurgical mortality was assessed, with a follow-up of 1 year. Presurgical morbidity was assessed in terms of cardiovascular compromise, metabolic acidosis, renal and/or hepatic dysfunction and closure of the duct before initiation of therapy. RESULTS: Of all cases (n = 144), 26.4% were diagnosed prenatally, with detection rates of 15.7% and 41.0% in the first and last 5 years of the study period, respectively. First-year mortality was significantly lower in cases with a prenatal diagnosis of TGA than in those without (0.0% vs 11.4%, respectively). Presurgical mortality (4.9%) only occurred in undetected simple TGA cases. Closure of the duct before treatment, renal dysfunction and hypoxia occurred significantly more often in the group without a prenatal diagnosis. CONCLUSIONS: The prenatal detection rate of TGA has increased significantly since the introduction of the screening program in 2007. Prenatal diagnosis is an important factor that contributes to survival of the infant in the first postnatal year. Furthermore, some morbidity indicators were significantly higher in the group without a prenatal diagnosis. These results justify efforts to improve prenatal screening programs.

Serogroup distribution of urogenital Chlamydia trachomatis in urban ethnic groups in The Netherlands.

The prevalence of Chlamydia trachomatis varies between ethnic groups in The Netherlands. It is, however, unknown whether this is associated with specific serogroups. The objective of this study was to determine whether serogroup distribution is associated with ethnic origin in the region of The Hague, The Netherlands. Serogroups of 370 microbiologically confirmed C. trachomatis-positive samples were analysed. The samples were obtained from 247 women and 123 men between January and October 2008, of self-reported Dutch Caucasian, Dutch Antillean, Surinamese, N. African/Turkish or other descent. We observed a difference in serogroup distribution comparing Dutch Caucasian women to Dutch Antillean women (χ2 for distribution P = 0·035). Serogroup C was more common in Dutch Antillean women, whereas serogroup B was less common (P = 0·03). This difference was not observed for Dutch Antillean men. The observed difference in distribution of C. trachomatis serogroups between ethnic groups is relevant for further transmission studies.

Analyses of multiple-site and concurrent Chlamydia trachomatis serovar infections, and serovar tissue tropism for urogenital versus rectal specimens in male and female patients.

OBJECTIVES: The aims of this study were: to determine the incidence of concurrent infections on a serovar level; to determine the incidence of multiple anatomical infected sites on a detection and genotyping level and analyse site-specific serovar distribution; to identify tissue tropism in urogenital versus rectal specimens. METHODS: Chlamydia trachomatis-infected patients in two populations were analysed: 75 visiting the outpatient department of obstetrics and gynaecology of the MC Haaglanden, and 358 visiting the outpatient sexually transmitted disease clinic, The Hague, The Netherlands. The PACE 2 assay (Gen-Probe) was used to detect C trachomatis from urethral, cervical, vaginal, oropharyngeal and anorectal swabs. C trachomatis genotyping was performed on all C trachomatis positive samples, using the CT-DT genotyping assay. RESULTS: Samples from 433 patients (256 female and 177 male) with confirmed C trachomatis infection were analysed. In 11 patients (2.6%), concurrent serovars in one anatomical sample site were present. In 62 (34.1%) female and four (9.3%) male patients, multiple sample site infections were found. A substantial percentage of women tested at the cervical/vaginal and rectal site were found to be positive at both sites (36.1%, 22/61). In men, D/Da and G/Ga serovars were more prevalent in rectal than urogenital specimens (p=0.0081 and p=0.0033, respectively), while serovar E was more prevalent in urogenital specimens (p=0.0012). CONCLUSIONS: The prevalence of multiple serovar infections is relatively low. Significant differences in serovar distribution are found in rectal specimens from men, with serovar G/Ga being the most prominent, suggesting tissue tropism.

Significantly higher serologic responses of Chlamydia trachomatis B group serovars versus C and I serogroups.

Chlamydia trachomatis serovars are divided into three serogroups, namely serogroup B, serogroup I (Intermediate) and serogroup C, and subsequently into 19 different serovars. Worldwide, serogroup B is the most prevalent followed by serogroup I. Clear differences have been observed in the duration of infection and growth kinetics between serovars from different serogroups in murine and cell culture models. Reasons for these observed differences are bacterial and host related, and are not well understood. The aim of this study was to determine the differences in immunoglobulin (Ig) G responses between the three serogroups in a group of patients infected with different serovars. Serovars were assessed from 235 C. trachomatispositive patients and quantitative IgG responses were determined. Analyses of variance were used to compare the IgG responses between the three serogroups. Of the serovars, 46% were B group (with serovar E the most prevalent: 35.3%), 39.6% were I group and 14.3% were C group. A highly significant difference in serologic response was shown when comparing the mean IgG concentrations (AU/mL) of patients having serovars in the most prevalent serogroup compared to the other serogroups: B = 135, C = 46 and I = 60 (B vs. C and B vs. I, P < 0.001). In conclusion, the most prevalent serovars generate the highest serologic responses.

Description of the ICTI consortium: an integrated approach to the study of Chlamydia trachomatis infection.

The use of an integrated approach to the study of Chlamydia trachomatis infection of the female genital tract, presented at the mini-symposium "Chlamydia trachomatis infections" and described in the thesis of Joseph M. Lyons, has resulted in the creation of the ICTI consortium. The ICTI consortium is based on strong interaction and collaboration between basic scientists, clinicians, epidemiologists, and health care policy makers. This translational approach will help to further the valuable insight into the immunopathogenesis of this sexually transmitted infection (STI) and the development of new intervention strategies, including the vaccines and screening programs necessary to effectively diagnose, treat and prevent C. trachomatis infection. A background of the need for this integrated approach is presented and the goals and participants of the consortium are described.

Comparison of serological assays for detection of Chlamydia trachomatis antibodies in different groups of obstetrical and gynecological patients.

New serological enzyme immunoassays (EIAs) were compared with microimmunofluorescence (MIF) as a "gold standard" to detect Chlamydia trachomatis antibodies in different groups of obstetrical, gynecological, and subfertile patients. There were no significant differences in seroprevalence rates, except for the group of C. trachomatis-positive patients (P < 0.01). Test characteristics were calculated for Chlamydia-EIA (Biologische Analysensystem GmbH, Lich, Germany) and pELISA (Medac, Wedel, Germany). pELISA seems to be a good alternative to MIF. It has high specificity and is easier to perform.

Clinical characteristics of Chlamydia trachomatis infections in a general outpatient department of obstetrics and gynaecology in the Netherlands.

OBJECTIVE: Evaluation of prevalence and risk factors of Chlamydia trachomatis infections in an outpatient obstetric and gynaecological population. METHODS: A prospective, observational study was performed at an inner city hospital in The Hague, Netherlands. 1368 women attending the outpatient department of obstetrics and gynaecology participated in the study. For detection of C trachomatis infections we used amplification of CT rRNA in urine samples (Gen Probe/AMPLIFIED-CT) and DNA probe for detection of CT rRNA from a urethral, endocervical and anal swab (Gen Probe/PACE 2). RESULTS: The overall prevalence of C trachomatis infections in our general obstetric and gynaecological population was 4.5%. The prevalence in women under 30 years of age was 8. 1%. We found age and postcoital bleeding to be significant risk factors. We did not find significant differences between women from different ethnic origin or between women using different kinds of contraceptives. 12 (19.4%) patients with C trachomatis infections were found positive by urine test only, and 15 (24.2%) only by DNA probe. CONCLUSIONS: Age is the most important risk factor in our population (overall prevalence 4.5%, prevalence in women under 20 years of age 15.8%). Analyses of urine and of endocervical specimens are complementary for the determination of the prevalence of C trachomatis infections in women. Cost effectiveness analysis is needed to determine to what extent age based screening and/or antibiotic prophylaxis before intrauterine manipulations is indicated.