David Seubert

Vasa previa: clinical presentations, outcomes, and implications for management.

OBJECTIVE: To review experience with diagnosis, clinical associations, and outcomes of vasa previa in a single institution. METHODS: This was a retrospective review of all identified vasa previa cases from January 1 1990, to June 30, 2010. RESULTS: Sixty cases of vasa previa were identified (53 singletons, seven twins); 56 cases were diagnosed before delivery. An abnormal cord insertion or abnormal placental location was present in 55 cases. Missed diagnoses were attributed to technical and observer factors. Preterm bleeding was encountered in 25 (42%) case group participants. Seven case group participants required an emergent delivery, with significant neonatal morbidity and mortality. Twin pregnancies had a significantly earlier median age at delivery of 32 weeks of gestation compared with 35 weeks of gestations in singletons (P=.01). The seven twin pregnancies had a 28.6% emergent preterm delivery rate, whereas singletons had a 4.1% rate (P=.07). In 14 case group participants, the membranous fetal vessel was located in the lower uterus and not directly over the cervix. The vessel location was not related to the risk of emergent delivery. CONCLUSION: Transvaginal ultrasound scans of at-risk patients can identify most cases of vasa previa. Preterm bleeding does not usually require immediate delivery. The rate of emergent preterm delivery was low in singleton pregnancies. Twins were delivered, on average, 3 weeks earlier than singletons. LEVEL OF EVIDENCE: III

Debate Preparation/Participation: An Active, Effective Learning Tool

Background: Passive educational techniques (such as lectures) are thought to be less productive than active learning. Purpose: We examined whether preparing for and participating in a debate would be an effective, active way to learn about a controversial topic. Methods: We compared quiz performance in residents who attended a lecture to residents who prepared for/participated in a debate. Twelve residents each participated in one lecture session and one debate session. Learning was evaluated via a quiz. Quizzes were given twice: before the debate/lecture and 1 week after the debate/lecture. Quiz scores were compared using repeated measures analysis of variance, with a p value of < .05 considered significant. A survey evaluating the usefulness of debating was given to all participants. Results: There was a statistically significant difference in the pretest mean quiz score between the debate and lecture groups: 78.3% and 52.5%, respectively ( p = .02). Similarly, on posttest quizzes, the average debater scored 85.8%, versus 61.7% for the lecture group ( p = .003). Although no one in the debate group scored lower on a follow-up quiz, 3 residents in the lecture group did worse on follow-up. Conclusions: When learning about a controversial topic, residents who prepared for/participated in a debate achieved higher quiz scores and were better at retaining information than those who attended a lecture. When faced with teaching a controversial topic, organizing a debate may be more effective than giving a lecture.

Advanced maternal age as a sole indication for genetic amniocentesis; risk-benefit analysis based on a large database reflecting the current common practice.

Abstract Aims: Recent advances in prenatal screening, including first and second trimester genetic screening as well as targeted sonography, have significantly improved the detection of trisomy 21. Therefore, several investigators have questioned the validity of recommending genetic amniocentesis to all women who are 35 years or older at delivery. Thus, we sought to investigate the risks and benefits associated with performing genetic amniocentesis in women whose sole indication for testing was advanced maternal age (AMA). Methods: A retrospective review of a Genzyme Genetics amniocentesis database (January 2006–December 2006) was performed. All specimens obtained from women of AMA as the sole indication were eligible for analysis. The amniocentesis-related potential fetal loss was calculated based on the traditional fetal loss rate of 1/200 as well as the recently published loss rate of 1/1600 procedures. Risk-benefit analysis was performed by comparing the number of trisomy 21 fetuses identified within the AMA group to the potential number of amniocentesis-related fetal losses within this group. Results: A total of 87,241 amniocentesis specimens were processed during the study period. AMA was the sole indication for genetic amniocentesis in 43,303 cases which formed the study group. In 399 (0.92%) of these cases, a trisomy 21 was identified. Assuming an amniocentesis related fetal loss rates of 1/200 or 1/1600; 217 or 27 fetal losses would have been expected, respectively. Conclusions: Our analysis suggests that the benefit of genetic amniocentesis for the sole indication of AMA far outweighs the potential amniocentesis-related fetal loss rate, regardless of the actual rate one considers.

Universal tuberculosis screening in pregnancy.

We reviewed our practice of universal tuberculosis (TB) screening in an at-risk pregnant population with regards to utility and patient compliance. The Gouverneur Healthcare Services prenatal database was analyzed for compliance with TB screening. Age, ethnicity, country of origin, and education level were also analyzed. Of 4049 patients, 95.0% were compliant with their purified protein derivative (PPD) testing. Universal screening identified 1935 (50.4%) PPD+ patients, with chest X-rays (CXR) available for 95.1%. Only one patient had a CXR consistent with active TB, although sputum testing was negative for acid-fast bacilli. Asian women were more likely to be PPD-compliant (adjusted odds ratio [aOR]: 4.94, 95% confidence interval [CI]: 2.34 to 10.45). Similarly, PPD+ Asian women were more likely to be compliant with CXR (aOR: 12.67, 95% CI: 3.44 to 46.7). U.S.-born women were significantly less likely to be compliant with PPD (aOR: 0.44, 95% CI: 0.30 to 0.64) or with CXR (aOR: 0.22, 95% CI: 0.08 to 0.61). Universal prenatal TB screening is associated with excellent compliance rates and is an effective way to identify a high prevalence of latent TB, but not active disease.

Predictors of severe perineal lacerations in Chinese women

Abstract Objective: Chinese women have been shown to have a higher incidence of severe perineal laceration compared to other ethnic groups. We sought to test the hypothesis that this risk is related to body mass index (BMI) or to a relative fetal-maternal size disproportion as measured by the ratio of the newborn birthweight to maternal BMI (BW:BMI). Methods: A retrospective cohort study was performed using a pre-existing obstetric database. Third- and fourth-degree perineal lacerations served as the primary outcome of interest. Logistic regression was used to compare Chinese women to other ethnic groups and adjust for confounders. Results: Three thousand and eighty-five singleton vaginal deliveries were identified, with BMI data available for 2281. Chinese women had a greater risk for severe perineal laceration compared to Caucasian (OR: 3.22; 95% CI: 0.73–14.32) and Hispanic women (OR: 2.88; 95% CI: 1.92–4.30). Multivariate analysis found that newborn birth weight plays a role (OR: 1.0012; 95% CI: 1.0007–1.0016), but BMI alone did not explain the discrepancy (P=0.89). However, the BW:BMI ratio appears to be a stronger predictor of laceration rate than either variable alone (OR: 1.011; 95% CI: 1.003–1.020). Conclusion: The higher risk of severe perineal laceration in Chinese women compared to other ethnicities can be attributed, in part, to a relative fetal-maternal size disproportion.

Intrahepatic cholestasis of pregnancy: detection with urinary bile acid assays.

Abstract Aims: To determine sensitivity and specificity of urine bile acid sulfate (UBAS) and non-sulfated urine bile acid (UBA) assays for detection of intrahepatic cholestasis of pregnancy (ICP). Methods: Urine was collected prospectively from healthy and pruritic patients evaluated for ICP. Results were expressed as a ratio to urinary creatinine. Results: Of 20 patients evaluated for ICP, 14 had confirmed ICP by serum testing and six had pruritus only. UBAS results were higher with ICP (P<0.001) and increased with gestational age in healthy controls. Adjusted for gestational age, the multiples of the median (MoM) were still higher (2.64±1.11, 1.05±0.54, P<0.001). The sensitivity was 100% and specificity 83% at 1.5 MoM in pruritic patients. UBA results were higher with ICP (23.0±9.8, 12.8±7.4, P<0.001), with sensitivity of 100% and specificity of 50% at 10.2 μmol/g cretinine. Conclusion: Urinary bile acids can detect or exclude ICP with serum abnormalities. Urine bile acid sulfates have higher specificity than non-sulfated urine bile acids at equivalent sensitivities, but co-detection of progestin sulfates is suspected.

The utility of fetal echocardiography after an unremarkable anatomy scan.

OBJECTIVE: To estimate whether fetal echocardiography detects major cardiac anomalies after normal anatomy ultrasound scan in patients at increased risk for having a fetus with congenital heart disease. METHODS: A computerized database was used to identify patients who underwent fetal echocardiography at the New York University Division of Pediatric Cardiology after anatomy ultrasound scan at the New York University Obstetrics and Gynecology Ultrasound Unit. Only patients with normal anatomy ultrasound scan results were included in the primary analysis. Patients were excluded if they had suspicious cardiac views on anatomy ultrasound scan or extracardiac anomalies. Major cardiac anomalies were defined as those judged by a blinded pediatric cardiologist as likely to require medical or surgical intervention in the first 6 months of life. RESULTS: Of 1,034 patients in the pediatric cardiology database, 536 patients underwent anatomy ultrasound scan at the New York University Obstetrics and Gynecology Department. Eighty patients in the case group were excluded for suspicious or inadequate cardiac views and 139 were excluded for extracardiac ultrasound findings. Of the remaining 317 patients with normal obstetric ultrasound scan results, none had a major cardiac malformation diagnosed on fetal echocardiography. CONCLUSION: In a tertiary care center with operators performing a high volume of ultrasound screenings, fetal echocardiography after normal anatomy ultrasound scan may be of limited benefit. LEVEL OF EVIDENCE: III

Does raising the glucose challenge test threshold impact birthweight in Asian gravidas

Abstract Objective: Some authors suggest a glucose challenge test (GCT) threshold of 150 mg/dL in Asian gravidas. The impact of such a policy on outcomes is unknown. Study Design: A retrospective cohort of 1705 Asian gravidas. Subjects (n=95) had a GCT of 140–150 mg/dL and underwent a 3-h glucose tolerance test (GTT). Matched controls (n=190) had a GCT of <140 mg/dL. Birthweight was the primary outcome and the secondary outcomes were cesarean delivery (CD) rate and macrosomia. Results: Eight subjects (11.9%) had gestational diabetes mellitus (GDM); none had GTT fasting values of >90 mg/dL. Mean birthweight was 3282 g in the subjects and 3238 g in the controls (P=0.39). There were no significant differences in the secondary outcomes. Conclusion: Compared with controls, study patients did not deliver significantly larger infants. However, raising the GCT threshold would have missed 8 subjects (11.9%) with GDM. Raising the GCT threshold to 150 mg/dL in Asian gravidas may unacceptably lower the sensitivity of the screening test.