Faculty Bibliography

Objective The objective of this study was to determine if first- and second-trimester biochemical markers for aneuploidy have an association with adverse pregnancy outcomes in twin gestations. Study Design A retrospective cohort study of patients who presented with dichorionic diamniotic twin gestations was performed. Patients with first-trimester low pregnancy-associated plasma protein A (PAPP-A) or low free beta human chorionic gonadotropin (beta-hCG), or second-trimester elevated alpha-fetoprotein (AFP), elevated inhibin A, elevated hCG, or low unconjugated estradiol were identified. The rates of adverse pregnancy outcomes were compared between patients with or without abnormal analytes with p < 0.05 used as significance. Results In this study, 340 pregnancies were included. Patients with a low PAPP-A had an increased risk for delivery < 37 weeks. Patients with an elevated second-trimester hCG had an increased risk for spontaneous delivery < 28 weeks and neonatal intensive care unit (NICU) admission. Patients with an elevated inhibin A had an increased risk of spontaneous delivery at < 37 and NICU admission. Patients with an elevated AFP had an increased risk of a NICU admission. Conclusion Certain abnormal aneuploidy markers are associated with an increased risk of adverse pregnancy outcomes in twin gestations.

Objectives-The nonstress test is currently the most widely used modality for antenatal surveillance in twin pregnancies, with a quoted false-positive rate of 11%-12%. Our objective was to report our experience with the sonographic portion of the biophysical profile in twin pregnancies as the primary screening modality.Methods-Women with twin pregnancies delivered by a single maternal-fetal medicine practice from 2005 to 2013 were included. We excluded monoamniotic twins. Twin pregnancies began weekly sonography for the biophysical profile starting at 32 to 33 weeks, or earlier if indicated. The nonstress test was performed if the sonographic biophysical profile score was less than 8 of 8. We reviewed biophysical profile scores and outcomes for all patients who delivered at 33 weeks or later to assess the false-positive rate for the biophysical profile, as well as the incidence of intrauterine fetal death (IUFD) after initiation of antenatal surveillance.Results-A total of 539 twin pregnancies were included. The incidence of IUFD per patient was 2 per 539 (0.4%; 95% confidence interval [CI], 0.1%-1.3%), and the incidence of IUFD per fetus was 2 per 1078 (0.19%; 95% CI, 0.05%-0.7%). The overall positive screen rate was 24 per 539 (4.45%; 95% CI, 3.0%-6.5%). The false-positive screen rate, defined as an abnormal biophysical profile that did not diagnose an IUFD or lead to delivery, was 10 per 539 (1.9%; 95% CI, 1.0%-3.4%).Conclusions-In twin pregnancies the use of the sonographic biophysical profile for routine antenatal surveillance has a low false-positive rate, with a very low incidence of IUFD. The sonographic biophysical profile should be considered as a primary mode for antenatal surveillance in twin pregnancies, with a reflex nonstress test for an abnormal score.

OBJECTIVE: To estimate the effect of resident participation on outcomes in women undergoing high-order cesarean deliveries. METHODS: We performed a retrospective cohort study of patients in one obstetric practice undergoing a third- or greater order cesarean delivery from 2005 to 2014. Patients with placenta previa, accreta, or failed vaginal birth after cesarean delivery were excluded. We compared outcomes between patients whose operations were performed by two attendings with patients whose operations were performed by one attending and one resident. Regression analysis was performed to control for differences at baseline. RESULTS: Three hundred seventy patients were included, 189 (51%) of whom had two attendings and 181 (49%) of whom had one attending and one resident. The mean operative time was slightly but significantly less in the two=attending group (60.9+/-17.3 compared with 62.5+/-18.3 minutes, adjusted P=.038). Otherwise, there were no significant differences in measured outcomes between the groups, including wound complications, blood loss (estimated and drop in hemoglobin), blood transfusion, major maternal morbidity (hysterectomy, cystotomy, bowel injury, intensive care unit admission, thrombosis, reoperation, death), postoperative endometritis, and postoperative days in the hospital. Among patients in the resident group, there was no difference in outcomes between cases performed by a junior (first or second year) resident compared with a senior (third or fourth year) resident. CONCLUSION: Resident participation does not negatively affect outcomes in patients undergoing high-order cesarean deliveries. Residents should be included in these complicated cases because they can obtain a significant learning experience without compromising patient safety.

Abstract Objective: To estimate the association between maternal obesity and adverse outcomes in patients without placenta previa or accreta undergoing a tertiary or higher cesarean delivery. Study design: Retrospective cohort of patients cared for by a single MFM practice undergoing a tertiary or higher cesarean delivery from 2005 to 2013. Patients attempting vaginal delivery and patients with placenta accreta and/or placenta previa were excluded. We estimated the association of maternal obesity (prepregnancy BMI >/= 30 kg/m2) and maternal outcomes. The primary outcome was a composite of severe maternal morbidity (uterine rupture, hysterectomy, blood transfusion, cystotomy requiring repair, bowel injury requiring repair, intensive care unit admission, thrombosis, re-operation, or maternal death). Results: Three hundred and forty four patients met inclusion criteria, 73 (21.2%) of whom were obese. The composite outcome was significantly higher in the obese group (6.8% versus 1.8%, p = 0.024, aOR 4.36, 95% CI 1.21, 15.75). The incidence of several individual adverse outcomes were also increased in obese women, including blood transfusion (4.1% versus 0.7%, p = 0.033, aOR 7.36, 95% CI 1.19, 45.34), wound separation or infection (20.5% versus 5.9%, p < 0.001, aOR 4.05, 95% CI 1.75, 9.36) and 1-min Apgar score less than 7 (6.8% versus 1.9%, p = 0.024, aOR 4.40, 95% CI 1.21, 15.94). Conclusions: In patients undergoing a tertiary or higher cesarean delivery without placenta previa or accreta, obesity increases the risk of adverse outcomes. Obese patients are at risk for blood transfusion, low 1-min Apgar scores and postoperative wound complications.

OBJECTIVES: To estimate the risk of spontaneous preterm birth in twin pregnancies based on transvaginal sonographic cervical length, fetal fibronectin (fFN) testing, and the gestational age at which these tests were performed. METHODS: Women with twin pregnancies, cervical length assessment, and fFN testing between 22 weeks and 31 weeks 6 days in a single maternal-fetal medicine practice from 2005 to 2013 were included. All testing was done on asymptomatic women on an out-patient basis. Women with monochorionic monoamniotic twins and twin-twin transfusion were excluded. Logistic regression analysis was used to estimate the risk of spontaneous preterm birth before 35, 32, and 28 weeks. RESULTS: Six hundred eleven patients were included and underwent a total of 2406 cervical length measurements and 2279 fFN tests over the course of the study period. The likelihood values for spontaneous preterm birth before 35, 32, and 28 weeks were 19.1%, 6.3%, and 2.3%, respectively. The risk of spontaneous preterm birth before 35 weeks increased with a decreasing cervical length (coefficient for the log of the odds ratio [OR coefficient], -0.13; P < .01; 95% confidence interval [CI], -0.22 to -0.037), a positive fFN result (OR coefficient, 1.04; P < .01; 95% CI, 0.45 to 1.64), as well as earlier gestational ages at testing (OR coefficient, -0.214; P < .01; 95% CI, -0.33 to -0.10). Similar results were seen for spontaneous preterm birth before 32 and 28 weeks. CONCLUSIONS: In asymptomatic patients with twin pregnancies, the cervical length, fFN, and gestational age are all significantly associated with spontaneous preterm birth.

OBJECTIVE:To evaluate whether a history of preterm birth or small for gestational age (SGA) in a singleton pregnancy is associated with an increased risk of recurrence of the same condition in a subsequent twin pregnancy. METHODS:Retrospective cohort study of twin pregnancies delivered in one maternal-fetal medicine practice from 2005 to 2014. Patients with a history of singleton preterm birth at less than 37 weeks of gestation were compared with patients with a history of singleton term birth and nulliparous patients. A similar analysis was performed for a history of SGA (birth weight less than 10%). RESULTS:Six hundred forty-seven twin pregnancies were included. The prior singleton gestational age at delivery was significantly positively correlated with the twin gestational age at delivery (P<.001), and the prior singleton birth weight was significantly positively correlated with the birth weight of the larger twin (P<.001) and the smaller twin (P<.001). The rate of twin preterm birth before 32 weeks of gestation was 3.5% in patients with a prior term birth, 9.2% in nulliparous patients, and 26% in patients with a prior preterm birth (P<.001). The rate of SGA in patients with a prior birth not complicated by SGA was 42.1%, in nulliparous women it was 54.4%, and in patients with a history of SGA it was 65.2% (P=.007). On regression analysis, prior preterm birth and SGA of a singleton pregnancy were independently associated with recurrence of the same condition in a subsequent twin pregnancy. CONCLUSION/CONCLUSIONS:Prior preterm birth and SGA in a singleton pregnancy increase the risk of the same condition in a subsequent twin pregnancy. We postulate that the extrinsic mechanism responsible for the pathophysiology of adverse outcomes in twin pregnancies overlaps with that in singleton pregnancies.

Abstract Objective: We sought to estimate the association between CL and fFN and each pathway leading to preterm birth in twin pregnancies. Methods: Cohort study of 560 patients with twin pregnancies who underwent routine serial CL and fFN screening from 22-32 weeks in one maternal fetal medicine practice from 2005-2013. We calculated the association between a short CL (