Rapid aneuploidy testing (knowing less) versus traditional karyotyping (knowing more) for advanced maternal age: what would be missed, who should decide?

OBJECTIVES: The application of rapid aneuploidy testing as a stand-alone approach in prenatal diagnosis is much debated. The major criticism of this targeted approach is that it will not detect other chromosomal abnormalities that will be picked up by traditional karyotyping. This study aimed to study the nature of such chromosomal abnormalities and whether parents would choose to terminate affected pregnancies. DESIGN: Retrospective study on a cytogenetic database. SETTING: Eight public hospitals in Hong Kong. PARTICIPANTS: The karyotype results of 19 517 amniotic fluid cultures performed for advanced maternal age (>or=35 years) from 1997 to 2002 were classified according to whether they were detectable by rapid aneuploidy testing. The outcomes of pregnancies with abnormal karyotypes were reviewed from patient records. RESULTS: In all, 333 (1.7%) amniotic fluid cultures yielded abnormal karyotypes; 175 (52.6%) of these were detected by rapid aneuploidy testing, and included trisomy 21 (n=94, 28.2%), trisomy 18 or 13 (n=21, 6.3%), and sex chromosome abnormalities (n=60, 18.0%). The other 158 (47.4%) chromosomal abnormalities were not detectable by rapid aneuploidy testing, of which 63 (18.9%) were regarded to be of potential clinical significance and 95 (28.5%) of no clinical significance. Pregnancy outcomes in 327/333 (98.2%) of these patients were retrieved. In total, 143 (42.9%) of these pregnancies were terminated: 93/94 (98.9%) for trisomy 21, 20/21 (95.2%) for trisomy 18 or 13, 19/60 (31.7%) for sex chromosome abnormalities, and 11/63 (17.5%) for other chromosomal abnormalities with potential clinical significance. There were no terminations in the 95 pregnancies in which karyotyping results were regarded to be of no clinical significance. CONCLUSIONS: 'Knowing less' by the rapid aneuploidy stand-alone testing could miss about half of all chromosomal abnormalities detectable by amniocentesis performed for advanced maternal age. Findings from two fifths of the latter were of potential clinical significance, and the parents chose to terminate one out of six of the corresponding pregnancies. If both techniques are available, parents could have enhanced autonomy to choose.

A case-controlled study comparing clinical course and outcomes of pregnant and non-pregnant women with severe acute respiratory syndrome.

OBJECTIVE: To compare the clinical courses and outcomes of pregnant severe acute respiratory syndrome (SARS) patients and non-pregnant SARS patients. DESIGN: A case-control study. SETTING: Tertiary Hospital for Infectious Disease. Sample Ten pregnant and 40 non-pregnant female patients infected with SARS. METHODS: Clinical course and outcomes of pregnant SARS patients were compared with a group of non-pregnant SARS patient. Cases and controls were matched with respect to sex, age, timing of contracting SARS, health care workers status and underlying illness. MAIN OUTCOME MEASURES: The incidence of intensive care unit admission, intubation, medical complications and death rate. RESULTS: Pregnancy had no discernible impact on clinical symptoms and presentation delay. Four out of the 10 pregnant patients, nevertheless, required endotracheal intubation and six were admitted to the intensive care unit (ICU), as compared with 12.5% intubation rate (P= 0.065) and 17.5% ICU admission rate (P= 0.012) in the non-pregnant group. More pregnant SARS patients developed renal failure (P= 0.006) and disseminated intravascular coagulopathy (P= 0.006), as compared with non-pregnant SARS group. There were three deaths in the pregnant group, whereas there was no death in the non-pregnant control group (P= 0.006). CONCLUSION: Pregnant women with SARS experience a worse clinical course and poorer outcomes compared with non-pregnant women.

Obstetric outcomes after cervical ripening by multiple doses of vaginal prostaglandin E2.

AIM: The study was designed to investigate the delivery outcome in women who required vaginal prostaglandin E2 for cervical priming prior to labor induction. MATERIALS AND METHODS: This retrospective cohort study included all singleton term deliveries that required labor induction over a 3-year period. Incidence and indications of obstetric interventions were compared among women who required different doses of vaginal prostaglandin E2 for cervical priming and who had induction by amniotomy and oxytocin infusion. RESULTS: Of 706 deliveries, 411 had favorable Bishop's scores and no vaginal prostaglandin E2 for cervical priming was required (group A); 268 required one or two doses of vaginal prostaglandin E2 for cervical priming (group B); and 27 required three or more doses (group C). The incidence of cesarean section was significantly higher in group C (48.1%) than in group A (19.0%) and group B (16.4%). The difference remained statistically significant when primiparous and multiparous women were analyzed separately. The risk of obstetric intervention was particularly high in primiparous women in group C (58.8% required emergency cesarean section and 23.5% had instrumental delivery). There was an increased frequency of all major indications for cesarean section in group C. CONCLUSION: The risk of emergency cesarean section was higher in women who required more than two doses of vaginal prostaglandin E2 for cervical priming compared to induction by one or two doses of vaginal prostaglandin E2 or by amniotomy and oxytocin infusion. These women should be informed regarding the high risk of intrapartum cesarean section, and the option of alternative methods of induction or elective cesarean section should be made available.

Nasal bone hypoplasia: is it a common finding amongst chromosomally normal fetuses of southern Chinese women?

OBJECTIVE: To assess the incidence of nasal hypoplasia among fetuses of southern Chinese women. METHODS: This prospective observational study was conducted at Princess Margaret Hospital, Hong Kong. All pregnant women referred for chromosomal studies before 14 weeks were assessed. The crown-rump length, nuchal translucency thickness, and nasal bone were assessed between 11 and 14 weeks. RESULTS: A total of 143 women were recruited. In 119 fetuses, facial profiles were successfully obtained and the presence or absence of nasal bones was assessed. One hundred and fourteen fetuses had normal karyotypes. The rate of absence nasal bone when assessed between 11-14 weeks was 0.88% in the fetuses with a normal karyotype. During the same period, 2 out of 3 fetuses with Down syndrome had absence of nasal bones. A nasal bone was visualized in one fetus with Edward syndrome and the other with Turner syndrome (45 X). CONCLUSION: The incidence of nasal hypoplasia is not increased among fetuses of southern Chinese women. Assessment of ossification of the nasal bone can be used to supplement first-trimester screening in Chinese women.

Use of umbilical artery Doppler velocimetry in the monitoring of pregnancy in women with pre-existing diabetes.

BACKGROUND: The usefulness of umbilical artery Doppler velocimetry for the monitoring of diabetic pregnancies is controversial. The aim of the present study was to assess whether umbilical artery Doppler velocity waveform analysis can predict adverse perinatal outcomes for pregnancies complicated by pre-existing diabetes mellitus. METHODS: All diabetic pregnancies (type 1 and 2) delivered at Mater Mothers' Hospital, Queensland, between 1 January 1995 and 31 December 1999 were included. All pregnant diabetic women were monitored with umbilical artery Doppler velocimetry at 28, 32, 36, and 38 weeks' gestation. Adverse perinatal outcome was defined as pregnancies with one or more of the following: small-for-gestational age, Caesarean section for non-reassuring cardiotocography, fetal acidaemia at delivery, 1-min Apgar of 3 or less, 5-min Apgar of less than 7, hypoxic ischaemic encephalopathy or perinatal death. Abnormal umbilical artery Doppler velocimetry was defined as a pulsatility index of 95th centile or higher for gestation. RESULTS: One hundred and four pregnancies in women with pre-existing diabetes had umbilical arterial Doppler studies carried out during the study period. Twenty-three pregnancies (22.1%) had an elevated pulsatility index. If the scans were carried out within 2 weeks of delivery, 71% of pregnancies with abnormal umbilical Doppler had adverse outcomes (P < 0.01; likelihood ratio, 4.2). However, the sensitivity was 35%; specificity was 94%; positive predictive value was 80%; and negative predictive value was 68%. Only 30% of women with adverse perinatal outcomes had abnormal umbilical arterial Doppler flow. CONCLUSION: Umbilical artery Doppler velocimetry is not a good predictor of adverse perinatal outcomes in diabetic pregnancies.

Human parvovirus B19 infection in pregnancy: should screening be offered to the low-risk population?

Human parvovirus B19 infection during pregnancy can result in fetal hydrops and death. Intra-uterine transfusion in hydropic fetuses affected by the virus can reduce perinatal deaths. Up to 33% of women with this infection are asymptomatic. In view of the significant adverse outcomes, the role of routine screening among low-risk pregnant women is discussed.

Transvaginal sonography in the detection of retained products of conception after first-trimester spontaneous abortion.

PURPOSE: The aim of this study was to assess the use of transvaginal sonography to detect retained products of conception after first-trimester spontaneous abortion. METHODS: All women who arrived at our hospital with spontaneous first-trimester abortions were included in this study and underwent transvaginal sonography. A sonographic diagnosis of "incomplete abortion" was based on a bilayer endometrial thickness of more than 8 mm. The final diagnosis of complete or incomplete abortion was based on the histopathologic findings at dilatation and curettage. The sensitivity and specificity of both clinical and sonographic examinations for detecting products of conception were assessed. RESULTS: A total of 113 women were recruited, and 14 were excluded for various reasons. Among 52 women with a clinically incomplete abortion, only 50% had retained products of conception. The use of transvaginal sonography resulted in a 29% (15/52) reduction of surgical intervention in these women. On the other hand, 30% (14/47) of women with a clinical diagnosis of complete abortion had retained products of conception. The sensitivity and specificity of cervical status for detecting retained products of conception were 65% and 56%, respectively, whereas the overall sensitivity and specificity of transvaginal sonographic examination (bilayer endometrial thickness 8 mm or less) were 100% and 80%, respectively. CONCLUSIONS: Transvaginal sonography is a useful supplement to clinical assessment in women who experience a spontaneous first-trimester abortion. If this modality is used to assess the uterine cavity, the cervical status can be ignored. Use of transvaginal sonography should reduce unnecessary general anesthesia and uterine curettage.

Fetal growth spurt and pregestational diabetic pregnancy.

OBJECTIVE: To assess the timing of fetal growth spurt among pre-existing diabetic pregnancies (types 1 and 2) and its relationship with diabetic control. To correlate fetal growth acceleration with factors that might influence fetal growth. RESEARCH DESIGN AND METHODS: This retrospective study involved all pregestational diabetic pregnancies delivered at a tertiary obstetric hospital in Australia between 1 January 1994 and 31 December 1999. Pregnancies with major congenital fetal anomalies, multiple pregnancies, small-for-gestational-age pregnancies (<10th centile), and those that were terminated before 20 weeks were excluded. In this cohort, pregnancies delivered at term had at least four ultrasound scans performed. The first scans were performed before 14 weeks of gestation and were regarded as dating scans. Abdominal circumference measurements were retrieved from the ultrasound reports. The z-scores for abdominal circumferences, according to the gestational age, were calculated. The gestations when the ultrasound scans were performed were stratified at four weekly intervals beginning at 18 weeks and continuing through the rest of the study. Majority of these diabetic pregnancies had ultrasound scans performed at 18, 28, 32, and 36 weeks. The abdominal circumference z-scores for pregnancies with large-for-gestational-age (LGA) babies (>90th centile for gestation) were compared with babies with normal birth weights. RESULTS: A total of 101 diabetic pregnancies were included. Diabetic mothers, who had LGA babies, had significantly higher prepregnancy body weight and BMI (P < 0.05). There were no differences in maternal age or parity among the two groups. There were also no differences in the first-, second-, and third-trimester HbA(1c) levels between the two groups. The abdominal circumference z-scores were significantly higher for LGA babies from 18 weeks and thereafter. The differences increased progressively as the gestation advanced. Maximum difference was noted in the third trimester (30-38 weeks). CONCLUSIONS: Fetal growth acceleration in LGA fetuses of diabetic mothers starts in the second trimester, from as early as 18 weeks. In this study, glucose control did not appear to have a direct effect on the incidence of LGA babies, and such observation might result from the effects of other confounding factors.

Diabetic family history is an isolated risk factor for gestational diabetes after 30 years of age.

BACKGROUND: Family history of diabetes is regarded as a risk factor for gestational glucose intolerance. Most selective screening policy includes family history as an indication of oral glucose tolerance test. However, few studies had evaluated the actual incidence of glucose intolerance in this group of women. METHODS: Pregnant women with oral glucose tolerance test performed for family history of diabetes over two consecutive years were identified. Receiver operating curve was used to identify the age cut-off that give the highest sensitivity and specificity. The incidence of glucose intolerance was compared between women with age above and below this cut-off. RESULTS: One hundred and eighty-seven women were identified. The age cut-off selected was 30.5 years. In young women (age