Faculty Bibliography

Background: Adherence to minimum weight gain recommendations in twin pregnancies as defined by the Institute of Medicine (IOM) guidelines is associated with improved pregnancy outcomes; however, these recommendations have yet to be made for underweight women (BMI < 18.5 kg/m²).Objective: To determine if existing pregnancy weight gain recommendations in twin gestations apply to women with underweight prepregnancy body mass index (BMI), and if these women have similar pregnancy outcomes to women with normal prepregnancy BMI.Methods: This is a retrospective cohort study of women with underweight (BMI < 18.5 kg/m²) and normal prepregnancy BMI (18.5-24.9 kg/m²) and twin pregnancies delivered > 24 weeks by a single Maternal Fetal Medicine (MFM) practice between 2005-2017. Weight gain patterns and pregnancy outcomes were compared between women with underweight prepregnancy BMI and normal prepregnancy BMI. The primary outcomes of the study were gestational age at delivery and intrauterine growth restriction.Results: A total of 664 women met inclusion criteria during the study period, 55 (8.3%) of whom had an underweight prepregnancy BMI, and 609 (91.7%) of whom had a normal prepregnancy BMI. There were no differences in baseline clinical and demographic characteristics between the groups, nor any differences in overall weight gain or weight gain patterns between the two groups. There were no significant differences between the groups in birthweight of the larger twin (2415 versus 2489 g, p = .26) or the smaller twin (2150 versus 2190 g, p = .55), gestational age at delivery (35.8 versus 35.8 weeks, p = .96), incidence of preterm birth < 34 weeks (16.4 versus 16.3%, p = .98), spontaneous preterm birth < 34 weeks (9.1 versus 11.7%, p = .57), or the incidence of either twin with a birthweight < 10% for gestational age (60.0 versus 56.0%, p = .57) or < 5% for gestational age (36.4 versus 30.9%, p = .40).Conclusions: Women with underweight prepregnancy BMI who gain equal weight to women with normal prepregnancy BMI have similar pregnancy outcomes. The recommendations for adequate weight gain in women with underweight prepregnancy BMI should therefore not exceed those for women with normal prepregnancy BMI.

Background: Preterm birth is a major cause of neonatal morbidity and mortality in the USA. In many patients at risk for preterm birth, cervical length (CL) screening is used to guide decisions regarding cerclage placement. Quality evidence shows that cerclage prolongs pregnancy in high-risk women with a short CL in women with a history of preterm birth and in women with painless cervical dilation in the second trimester, though the degree of cervical shortening, dilation, or gestational age at cerclage placement are not consistently associated with the subsequent rate of preterm birth. Our objective was to determine if cervical length (CL), cervical dilation or gestational age (GA) at the time of cerclage placement are associated with preterm birth among women undergoing ultrasound-indicated or exam-indicated cerclage.Study design: This was a retrospective cohort study of all patients with a singleton pregnancy who underwent ultrasound-indicated or exam-indicated Shirodkar cerclage placement at a single maternal-fetal medicine practice in New York City between November 2005 and May 2017. All patients included in the study had previously undergone CL screening for an increased risk of preterm birth (for example, prior spontaneous preterm birth or mid-trimester loss, prior cervical excision). The cervical length or dilation and GA at the time of cerclage placement were collected, as were demographic and obstetric outcome data for the current pregnancy. The primary outcome was delivery <36 or ≥36 weeks. Planned subgroup analyses of the primary outcome were performed based on CL at the time of ultrasound-indicated cerclage (0-9 mm, 10-19 mm, ≥20 mm), cervical dilation at the time of physical exam-indicated cerclage (<2 cm vs. ≥2 cm), and gestational age at cerclage placement (<20 weeks vs. ≥20 weeks). Data were analyzed using the Student's t-test and chi-square test for trend.Results: There were 123 and 39 patients in the ultrasound- and exam-indicated cerclage groups, respectively. Twenty six (21.2%) patients in the ultrasound-indicated subgroup and 24 patients (61.5%) in the exam-indicated subgroup delivered <36 weeks. CL (16.4 versus 17.6 mm, p = .28) and GA (19.7 versus 20.0 weeks, p = .58) at the time of ultrasound-indicated cerclage placement were not significantly different in patients who delivered <36 and ≥36 weeks' gestation, respectively. Women with cervical dilation ≥2 cm prior to exam-indicated cerclage placement were significantly more likely to deliver <36 weeks when compared to women with cervical dilation <2 cm (77.8 versus 47.6%, p = .05); however, there were no significant differences in rates of preterm birth <28 and <32 weeks between these two groups (38.9 versus 23.8%, p = .31 and 50.0% versus 28.6%, p = .17, respectively).Conclusions: Cervical length and GA at the time of ultrasound-indicated Shirodkar cerclage placement do not appear to impact the likelihood of preterm birth <36 weeks, while cervical dilation ≥2 cm at the time of exam-indicated Shirodkar cerclage is associated with an increased rate of preterm birth <36 weeks, but not earlier gestational ages at delivery.

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.

The vast individual differences in the developmental origins of risk and resilience pathways combined with sophisticated capabilities of big data science increasingly point to the imperative of large, neurodevelopmental consortia to capture population heterogeneity and key variations in developmental trajectories. At the same time, such large-scale population-based designs involving multiple independent sites also must weigh competing demands. For example, the need for efficient, scalable assessment strategies must be balanced with the need for nuanced, developmentally sensitive phenotyping optimized for linkage to neural mechanisms and specification of common and distinct exposure pathways. Standardized epidemiologic batteries designed for this purpose such as PhenX (consensus measures for Phenotypes and eXposures) and the National Institutes of Health (NIH) Toolbox provide excellent "off the shelf" assessment tools that are well-validated and enable cross-study comparability. However, these standardized toolkits can also constrain ability to leverage advances in neurodevelopmental measurement over time, at times disproportionately advantaging established measures. In addition, individual consortia often expend exhaustive effort "reinventing the wheel," which is inefficient and fails to fully maximize potential synergies with other like initiatives. To address these issues, this paper lays forth an early childhood neurodevelopmental assessment strategy, guided by a set of principles synthesizing developmental and pragmatic considerations generated by the Neurodevelopmental Workgroup of the HEALthy Brain and Child Development (HBCD) Planning Consortium. These principles emphasize characterization of both risk- and resilience-promoting processes. Specific measurement recommendations to HBCD are provided to illustrate application. However, principles are intended as a guiding framework to transcend any particular initiative as a broad neurodevelopmentally informed, early childhood assessment strategy for large-scale consortia science.

Although electrophysiological (electroencephalography) measures of executive functions (e.g. error monitoring) have been used to predict academic achievement in typically developing children, work investigating a link between error monitoring and academic skills in children with autism spectrum disorder is limited. In this study, we employed traditional electrophysiological and advanced time-frequency methods, combined with principal component analyses, to extract neural activity related to error monitoring and tested their relations to academic achievement in cognitively able kindergarteners with autism spectrum disorder. In total, 35 cognitively able kindergarteners with autism spectrum disorder completed academic assessments and the child-friendly "Zoo Game" Go/No-go task at school entry. The Go/No-go task successfully elicited an error-related negativity and error positivity in children with autism spectrum disorder as young as 5 years at fronto-central and posterior electrode sites, respectively. We also observed increased response-related theta power during errors relative to correct trials at fronto-central sites. Both larger error positivity and theta power significantly predicted concurrent academic achievement after controlling for behavioral performance on the Zoo Game and intelligence quotient. These results suggest that the use of time-frequency electroencephalography analyses, combined with traditional event-related potential measures, may provide new opportunities to investigate neurobiological mechanisms of executive function and academic achievement in young children with autism spectrum disorder.

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.

Objective: To perform a systematic review of interventions to reduce maternal mortality in New York.Study design: We conducted a systematic review of literature published between 2000 and January 2019 reporting interventions to reduce maternal mortality in New York using PubMed and search terms: pregnancy-related death or maternal mortality OR maternal death AND New York. Eight hundred and ninety-three articles were reviewed by title, content, and focus on New York interventions or policies. Ten met inclusion criteria. A second review of the Safe Motherhood Initiative (SMI) identified an additional six articles.Results: Nine articles described hospital-based initiatives; one described a community-based initiative. No prospective randomized controlled trials in a nonsimulated setting were identified. Several articles described SMI bundles; one tested simulated checklist implementation. Three presented results of bundle implementation but did not significantly impact measured maternal mortality and/or morbidity. The single community-based initiative provided doulas to low-income women, yielding significantly lower rates of preterm birth and low birthweight, but no difference in cesarean deliveries compared to other women in the community.Conclusion: Current hospital-based interventions have not reduced maternal mortality in New York. The single community-based intervention identified reduced adverse birth outcomes. Continued concern about maternal mortality in New York suggests community-based approaches should be considered to affect change in conjunction with longer term hospital-based interventions.

Objective: Microbiome exposure at birth has been associated with long-term pediatric outcomes. However, it is difficult to determine if differences in outcomes are truly due to microbiome exposure at birth or other exposures after birth and in early infancy. Using a twin cohort, we sought to determine the association between length of exposure to the maternal vaginal-fecal microbiome and long-term pediatric health outcomes by comparing outcomes between presenting and nonpresenting twins born to women who labored.Methods: We performed a mail-based survey study of women in a single maternal-fetal medicine practice who delivered twin pregnancies ≥24 weeks. The survey study was sent to women when twins were between 2 and 10 years old to assess the long-term health outcomes, including any medical diagnoses or problems with grown and development. For this study, we included all women who labored, and we compared health outcomes for the presenting versus nonpresenting twin with the primary outcome being the development of asthma/reactive airway disease and allergies. The length of exposure to the maternal vaginal-fecal microbiome was measured using the time from rupture of membranes (ROM) to delivery of each twin. Chi-square and Student's t-test were used.Results: Two hundred fifty-seven sets of twins were eligible for analyses. The presenting twin had a longer time of ROM than the nonpresenting twin (617 ± 2408 min versus 2 ± 5 minutes, p < .001). There were no significant differences between health outcomes for the presenting versus nonpresenting twin in the overall cohort, including the development of asthma/reactive airway disease (9.3 versus 10.1%, p = .77) or allergies (12.5 versus 7.8%, p = .08). There were no differences in any outcomes when comparing the presenting versus nonpresenting twin for those twins delivered vaginally or by cesarean delivery.Conclusion: In twins born to women who labored and either delivered vaginally or via cesarean section, delivery order was not associated with any significant increase in defined adverse pediatric outcomes, including the development of asthma or allergies. Using twins as a model for microbiome exposure may help to elucidate the role of the maternal vaginal-fecal microbiome on long-term pediatric health outcomes.

Background: Prior studies have shown an association between history of loop electrode procedures (LEEP) and spontaneous preterm delivery (SPTD) independent of midtrimester cervical length. These studies suggest that there may be other factors beyond an individual cervical length, which contributes to identifying at risk pregnancies. Objective: The objective of this study is to determine the association between change in cervical length and SPTD in women with a history of LEEP. Study design: This is a retrospective cohort study of singleton nulliparous women with a history of LEEP who received serial cervical length measurements at a single institution between 2012 and 2016. Women with serial cervical lengths and available outcome data were included. The cervical length at different gestational ages and rate of change in length was compared with the risk for SPTD < 37 weeks using Student's t-test. Results: One hundred thirty subjects met inclusion criteria for the study. The mean cervical length (35.3 versus 39.8 mm, p = 0.042 at 16 weeks; 32.2 versus 37.8 mm, p < 0.01 at 20 weeks; 29.9 versus 35.6 mm, p = 0.027 at 24 weeks; 21.6 versus 33.4 mm, p < 0.01 at 28 weeks) was significantly different between women who had a SPTD < 37 weeks compared to women who did not. The average rate of change in transvaginal cervical length between 16 to 28 weeks was significantly different between women who had a SPTD < 37 weeks compared to women who did not (-1.4 versus 0.4 mm/wk, p < 0.01). Conclusion: Women with a history of LEEP who had a SPTD < 37 weeks had a shorter cervical length at 16, 20, 24, and 28 weeks' gestation and a higher rate of change in cervical length between 16 and 28 weeks than women without a history of SPTD. Our findings support the concept of the preterm birth syndrome as an evolving biophysical process rather than a distinct event, suggesting improved prediction in the setting of prior history of a LEEP with serial imaging.

Background: While adequate weight gain in twin pregnancies with normal prepregnancy BMI has been associated with improved pregnancy outcomes, it remains unclear whether adequate weight gain in patients with overweight or obese prepregnancy BMI is associated with similarly improved pregnancy outcomes, and whether this comes at the expense of maternal health risks such as increased risk for gestational diabetes or hypertension. Objective: To estimate the association between adherence to weight gain recommendations and pregnancy outcomes in overweight and obese women with twin pregnancies. Methods: This is a retrospective cohort study of women with overweight (BMI 25.0-29.9 kg/m²) and obese prepregnancy BMI (≥30.0 kg/m²) and twin pregnancies delivered >24 weeks by a single MFM practice between 2005 and 2017. Baseline characteristics, weight gain patterns, and pregnancy outcomes were compared between women who met or exceeded, and who did not meet gestational weight gain requirements, as recommended by the Institute of Medicine (IOM) in 2009. Since total weight gain is also dependent on gestational age at delivery, we used weight gain per week to define adequate weight gain for overweight (0.85 lb/week) and obese (0.68 lb/week) women. Results: A total of 252 overweight and obese women with twin pregnancies met inclusion criteria, 171 (67.9%) of whom met or exceeded weight gain requirements and 81 (32.1%) of whom did not. There were no differences in baseline clinical and demographic characteristics between the two groups. Women with inadequate weight gain had significantly less weight gain in each trimester, as well as less total weight gain for the whole pregnancy. Women with inadequate average gestational weight gain had significantly lower birthweights of the larger twin (2440 versus 2675 g, p = .001) and the smaller twin (2212 versus 2398 g, p = .005), higher incidence of spontaneous preterm birth <37 weeks (33.3 versus 21.1%, p = .03), higher incidence of premature rupture of membranes (24.7 versus 11.7%, p = .008), and greater likelihood of any twin birthweight < 10th percentile for gestational age (51.9 versus 35.5%, p = .01). There were no differences in the likelihood of cesarean delivery, preeclampsia, or gestational diabetes between the two groups. These results did not differ after excluding the 24 women in the cohort with excessive weight gain. Conclusions: For overweight and obese women with twin gestations, meeting the IOM recommendations for weight gain in pregnancy is associated with improved pregnancy outcomes. Condensation Women with overweight or obese prepregnancy BMI in twin gestations who gain the recommended amount of weight in pregnancy have improved pregnancy outcomes.