Faculty Bibliography

BACKGROUND:There are limited data to guide the diagnosis and management of vasa previa. Currently, what is known is largely based on case reports or series and cohort studies. OBJECTIVE:(s): To systematically collect and classify expert opinions and achieve consensus on the diagnosis and clinical management of vasa previa using focus group discussions (FGD) and a Delphi technique. STUDY DESIGN/METHODS:A four-round FGD and a three-round Delphi survey of an international panel of experts on vasa previa were conducted. Experts were selected based on their publication record on vasa previa. First, we convened an FGD panel of 20 experts and agreed on which issues were unresolved in the diagnosis and management of vasa previa. A three-round anonymous electronic survey was then sent to the full expert panel. Survey questions were presented on the diagnosis and management of vasa previa that the experts were asked to rate on a 5-point Likert scale (from strongly disagree = 1 to strongly agree = 5). Consensus was defined as a median score of 5. Following responses to each round, any statements that had median scores of 3 or less were deemed to have had no consensus and excluded. Statements with a median score of 4 were revised and re-presented to the experts in the next round. Consensus and non-consensus statements were then aggregated. RESULTS:Sixty-eight international experts were invited to participate in the study, of which 57 participated. Experts were from 13 countries on five continents and have contributed to over 80% of published cohort studies on vasa previa, as well as national and international society guidelines. Completion rates were 84%, 93%, 91% for the first, second, and third rounds, respectively, and 71% completed all three rounds. The panel reached a consensus on 26 statements regarding the diagnosis and key points of management of vasa previa, including: 1) While there is no agreement on a distance between the fetal vessels and the cervical internal os to define vasa previa, the definition should not be limited to a 2 cm distance; 2) All pregnancies should be screened for vasa previa with routine examination for placental cord insertion and a color Doppler sweep of the region over the cervix at the second-trimester anatomy scan; 3) When a low-lying placenta or placenta previa is found in the second trimester, a transvaginal ultrasound with Doppler should be performed at around 32 weeks to rule out vasa previa; 4) Outpatient management of asymptomatic patients without risk factors for preterm birth is reasonable; 5)Asymptomatic patients with vasa previa should be delivered by scheduled cesarean between 35- and 37-weeks of gestation; and 6) There was no agreement on routine hospitalization, avoidance of intercourse, or use of 3-dimensional ultrasound for diagnosis of vasa previa. CONCLUSIONS:Through FGD and a Delphi process, an international expert panel reached consensus on the definition, screening, clinical management, and timing of delivery in vasa previa, which could inform the development of new clinical guidelines.

Collective interest in global health training during US obstetrics/gynecology (Ob/Gyn) residency has grown over the past decade. The benefits of participation in global health electives have been well described. This review seeks to determine what literature exists regarding the use of Accreditation Council for Graduate Medical Education (ACGME) Milestones in Ob/Gyn residency as an assessment tool to evaluate global health programs. The PubMed database was searched from July 14, 2020 to August 20, 2021, using six search phrases: "global health curriculum(s) and ACGME"; "international health and ACGME"; "global health and Ob/Gyn residency"; "international health and Ob/Gyn residency"; "global health and Ob/Gyn residents"; and "global health curriculum(s) and Ob/Gyn residency." Publications that described global health programming outside of residency, within other medical specialties, and/or at non-US institutions were excluded from this review. In total, 259 publications resulted from the preliminary search. Five articles described US global health residency training in Ob/Gyn in some capacity. Only one publication described a specific global health elective and its evaluation with respect to ACGME Milestones. Despite growing popularity of global health electives among residency programs, few are assessing the educational value of these offerings using ACGME Milestones or describing these efforts in the literature.

Twin pregnancies are common and associated with pregnancy complications and adverse outcomes. Prenatal clinical management is intensive and has been hampered by inferior screening and less acceptable invasive testing. For aneuploidy screening, meta-analyses show that non-invasive prenatal testing (NIPT) through analysis of cell-free DNA (cf-DNA) is superior to serum and ultrasound-based tests. The positive predictive value for NIPT is driven strongly by the discriminatory power of the assay and only secondarily by the prior risk. Uncertainties in a priori risks for aneuploidies in twin pregnancies are therefore of lesser importance with NIPT. Additional information on zygosity can be obtained using NIPT. Establishing zygosity can be helpful when chorionicity was not reliably established early in pregnancy or where the there is a concern for one versus two affected fetuses. In dizygotic twin pregnancies, individual fetal fractions can be measured to ensure that both values are satisfactory. Vanishing twins can be identified by NIPT. Although clinical utility of routinely detecting vanishing twins has not yet been demonstrated, there are individual cases where cf-DNA analysis could be helpful in explaining unusual clinical or laboratory observations. We conclude that cf-DNA analysis and ultrasound have synergistic roles in the management of multiple gestational pregnancies.

BACKGROUND:Multifetal Pregnancy Reduction is a technique used to reduce the fetal number with the goal of mitigating risks of adverse outcomes associated with multiple gestations. Monochorionic diamniotic twin pregnancies are subject to unique complications, contributing to adverse pregnancy outcomes. Thus, patients have an option to electively reduce one fetus with the goal of improving outcomes. OBJECTIVE:Our objective was to compare outcomes of elective reduction of monochorionic diamniotic twins by radiofrequency ablation to planned ongoing monochorionic diamniotic twins. STUDY DESIGN/METHODS:We performed a retrospective review of 315 monochorionic diamniotic twin gestations that underwent first-trimester ultrasound within one institution. Planned electively reduced twins were compared with ongoing monochorionic diamniotic twins. All reductions were performed via radiofrequency ablation of the cord insertion site into the fetal abdomen. The primary outcome was preterm birth less than 36 weeks. Secondary outcomes included gestational age at delivery, preterm birth less than 37, 34, 32, and 28 weeks, unintended loss, and adverse perinatal outcomes. RESULTS:Among 315 monochorionic diamniotic pregnancies, 14 (4.4%) underwent elective multifetal pregnancy reduction and 301 (95.6%) were planned ongoing twins. The mean GA of RFA in the elective MPR group was 15.1 ± 0.68 weeks. Patients who underwent elective multifetal pregnancy reduction had significantly higher maternal age (p<0.01) and were more likely to be Asian (p<0.01). They were also more likely to have undergone in vitro fertilization (p=0.03) and chorionic villus sampling (p<0.01). There was a significantly higher rate of term deliveries in the elective radiofrequency ablation group compared to ongoing twins (GA 38 weeks (IQR, 36.1, 39.1) vs. 35.9 weeks (IQR, 34, 36.9), (p<0.01)). Patients with ongoing pregnancies had a trend of increased rate of preterm birth less than 36 weeks (OR 3.4, 95% CI 1.0-12.0; p=0.06), a significantly increased risk of preterm birth less than 37 weeks (OR 8.0, 95% CI 2.4-26.4; p<0.01), and no difference less than 34, 32, or 28 weeks. All patients who underwent elective radiofrequency ablation had successful pregnancies with no pregnancy losses or terminations. Of ongoing gestations, 36 required procedures including 16 (5.3%) medically-indicated radiofrequency ablation, 14 (4.6%) laser ablation, and six (1.9%) amnioreductions. Twenty-two patients (7.3%) with planned ongoing twins had total pregnancy loss less than 24 weeks. Twelve (4.0%) had unintended loss of one fetus before 24 weeks in the ongoing pregnancy cohort and 12 (4.0%) had unintended loss of both fetuses before 24 weeks. Five patients (1.7%) in the ongoing pregnancy group had intrauterine fetal demise greater than 24 weeks and 10 patients (3.3%) electively terminated both fetuses. There was no significant difference in loss rates between the two groups. CONCLUSION/CONCLUSIONS:In this study of monochorionic diamniotic twins, patients who elected to undergo multifetal pregnancy reduction had significantly lower rates of preterm birth less than 37 weeks and a lower trend of preterm birth less than 36 weeks without an increased risk of pregnancy loss. Median gestational age at delivery was significantly higher at 38 weeks in the elective multifetal pregnancy reduction group, as compared to 35.9 weeks in the ongoing pregnancy group. Further research is needed to clarify if multifetal pregnancy reduction improves long-term outcomes.

OBJECTIVE: This study aims to estimate the association between abnormal placental histopathology, fetal growth restriction (FGR), and preeclampsia (PEC) in twin pregnancies. STUDY DESIGN/METHODS:-tests were used for analysis. RESULTS: = 0.46; aOR: 0.79, 95% CI: 0.53-1.18). CONCLUSION/CONCLUSIONS: In twin pregnancies, FGR and PEC are not associated with abnormal placental histopathology. This suggests that the pathologic placental manifestations of these conditions may differ in twins and include factors other than those commonly described in singletons.

OBJECTIVE/UNASSIGNED:To evaluate which parameters of a sonographic cervical length measurement are associated with preterm birth in women with ultrasound- or exam-indicated cerclage. METHODS/UNASSIGNED:This was a retrospective cohort study of women with singleton pregnancies who underwent ultrasound- or exam-indicated Shirodkar cerclage by a single maternal-fetal medicine practice between 2011 and 2019. All patients underwent sonographic cervical length measurement 2-3 weeks after cerclage placement, and then every 2-4 weeks up to 32 weeks. The images from the first and second post-cerclage cervical lengths were reviewed. Total cervical length, upper cervical length (from the internal cervical os to the cerclage), and lower cervical length (from the cerclage to the external os) were measured. The primary outcome for this study was gestational age at delivery. RESULTS/UNASSIGNED:=.166, respectively, for the second scan). CONCLUSIONS/UNASSIGNED:Postcerclage total cervical length and upper cervical length are both associated with gestational age at delivery and risk of preterm birth, but not independently. After ultrasound- or exam-indicated cerclage, sonographic monitoring of either the total cervical length or the upper cervical length might be predictive of gestational age at delivery and the risk of preterm birth.

OBJECTIVE: This study was aimed to compare maternal and neonatal outcomes between women with twin pregnancies who underwent induction of labor with those women who had planned Cesarean delivery (CD). STUDY DESIGN/METHODS: This is a retrospective cohort study of women with twin pregnancies ≥ 24 weeks with an indication for delivery but not in labor. Two groups were examined, women who underwent induction and women who underwent planned CD. Maternal and neonatal outcomes were compared between groups both for deliveries at gestational age ≥ 37 weeks and < 37 weeks. RESULTS: < 0.01), but this was not significant on adjusted odds ratio analysis (aOR = 0.71, 95% CI: 0.19-2.66). CONCLUSION/CONCLUSIONS: Labor induction in twin gestations have improved maternal outcomes and similar neonatal outcomes compared with planned CD.

INTRODUCTION/BACKGROUND: Data regarding transplacental passage of maternal coronavirus disease 2019 (COVID-19) antibodies and potential immunity in the newborn is limited. CASE REPORT/METHODS: We present a 25-year-old multigravida with known red blood cell isoimmunization, who was found to be COVID-19 positive at 27 weeks of gestation while undergoing serial periumbilical blood sampling and intrauterine transfusions. Maternal COVID-19 antibody was detected 2 weeks after positive molecular testing. Antibodies were never detected on cord blood samples from two intrauterine fetal cord blood samples as well as neonatal cord blood at the time of delivery. CONCLUSION/CONCLUSIONS: This case demonstrates a lack of passive immunity of COVID-19 antibodies from a positive pregnant woman to her fetus, neither in utero nor at the time of birth. Further studies are needed to understand if passage of antibodies can occur and if that can confer passive immunity in the newborn. KEY POINTS/CONCLUSIONS:· Passive immunity should not be assumed in COVID-19 infection in pregnancy.. · Isoimmunization may impair passive immunity of certain antibodies.. · Vaccination to or maternal infection of COVID-19 may not be protective for the fetus..

OBJECTIVE: To determine what proportion of women with a short cervical length (CL) without a history of spontaneous preterm birth (SPTB) will ultimately be dilated at <24 weeks. STUDY DESIGN/METHODS: This is a retrospective cohort study of women with singleton pregnancies with a short CL (≤25 mm) between 16 and 22 weeks' gestational age (GA). We excluded women with a history of SPTB. We examined the progression of women with short CL based on the CL measurement and GA at diagnosis. The primary outcome was cervical dilation or spontaneous delivery <24 weeks. RESULTS:(range: 15-22) weeks. Women with a CL <15 mm were more likely to have cervical dilation or loss prior to 24 weeks than women whose CL was 15 to 25 mm (42.5 vs. 11.9%, <0.001, adjusted odds ratio: 3.72, 95% confidence interval: 1.52-9.09). GA at diagnosis was not associated with risk of progression. CONCLUSION/CONCLUSIONS: In women with a short CL without a history of SPTB, the risk of dilation or pregnancy loss <24 weeks is significant, approaching 50% for women with a CL <15 mm.

BACKGROUND:Vasa previa is a serious obstetric complication that can result in fetal hemorrhage and demise upon spontaneous labor. Suggested management for vasa previa is elective hospitalization and caesarean delivery prior to spontaneous labor. There is little reported evidence of the rate of vasa previa resolution over the course of gestation. Identification of the resolution rate and of factors predictive of resolution could potentially improve clinical management and patient counseling. OBJECTIVE:To identify the resolution rate of vasa previa across gestation and to determine clinical and sonographic factors that are associated with vasa previa resolution. STUDY DESIGN/METHODS:We conducted a retrospective cohort study of all women diagnosed with vasa previa in a single ultrasound unit between 2005 and 2018. Vasa previa was defined as a fetal vessel within 2 cm of the internal cervical os on transvaginal sonography. The primary outcome was vasa previa resolution, defined as migration of the vasa previa to > 2 cm away from the internal os. RESULTS:One hundred women with vasa previa were included, diagnosed at a mean gestational age (GA) of 22.8 +/- 4.9 weeks. Thirty-nine women (39.0%, 95% CI 30% - 49%) had resolution of vasa previa at a mean gestational age of 28.6 +/- 4.7 weeks. Factors associated with vasa previa resolution were earlier GA at diagnosis (aOR 6.10, 95% CI 1.92-19.40), vasa previa not covering the internal os at diagnosis (aOR 8.29, 95% CI 2.79-24.62) and vasa previa not being the result of a resolved placenta previa (aOR 2.85, 95% CI 1.01-8.03). One woman with a dichorionic twin pregnancy and vasa previa resolution (at 31 weeks, fetal vessels located 2.8 cm from the internal os) presented at 33 weeks with massive bleeding and fetal demise of twin A. It was unclear if the demise was related to vasa previa or placental abruption. CONCLUSIONS:39% of vasa previas in our population resolved over the course of pregnancy. Earlier GA at diagnosis, vasa previa not covering the internal os, and not having a resolved placenta previa are all independently associated with an increased likelihood of vasa previa resolution. Women with vasa previa should be followed serially to assess for vasa previa resolution, as many will resolve in the third trimester.