Birth Birthweight Research Articles

Using epidemiological and health economic measures to inform maternity staffing decisions: A guide

BackgroundThere is growing concern around unnecessary intervention (particularly caesarean section) at birth in high-income countries. Caseload midwifery care aims to offset this, but is perceived to be costly to health services. AimTo use epidemiological and health economic techniques to estimate health outcomes and cost-savings of different levels of equivalent full time (EFT) midwives working in caseload midwifery care. MethodsTwo simulations were conducted — one assuming 10 EFT midwives working in a caseload model, with 35 women per caseload, and one assuming 50 EFT midwives working in a caseload model, with 45 women per caseload. Both were based on a sample of 5000 women. The main model inputs included rates of health outcomes for women (caesarean section, epidural anaesthesia, and episiotomy) and infants (low birthweight and admissions to special care nursery (SCN) or neonatal intensive care unit (NICU)), and the cost savings associated with health outcome avoidance. FindingsThe first simulation estimated 27 fewer caesarean sections, 12 fewer epidurals, 12 fewer episiotomies, 10 fewer low birthweight births, and 23 fewer infants admitted to SCN or NICU annually, at a total cost saving of AU$1,874,715. The second simulation estimated 173 fewer caesarean sections, 76 fewer epidurals, 76 fewer episiotomies, 65 fewer low birthweight births, and 150 fewer infants admitted to SCN or NICU annually, at a total cost saving of AU$12,051,741. ConclusionThis study provides local-level decision-makers with a decision-tool to calculate the potentially avoidable health outcomes and cost savings associated with implementing caseload midwifery care in their own service.

Differences in pregnancy and perinatal outcomes among symptomatic versus asymptomatic COVID-19-infected pregnant women: a systematic review and meta-analysis

BackgroundThere is dearth of information on COVID-19’s impact on pregnant women. However, literature reported trends of COVID-19 differ, depending on the presence of clinical features upon presentation.ObjectiveThis systematic review aimed to assess differences in risk factors, management, complications, and pregnancy and perinatal outcomes in symptomatic vs. asymptomatic pregnant women with confirmed SARS-CoV-2 infection.MethodsA search was run on electronic databases to identify studies reporting COVID-19 in pregnancy. Meta-analysis was performed and odds ratios and mean difference with 95% confidence intervals were calculated using Review Manager 5.4. Review Prospero registration number CRD42020204662.ResultsWe included ten articles reporting data from 3158 pregnancies; with 1900 symptomatic and 1258 asymptomatic pregnant women. There was no significant difference in the mean age, gestational age, and body mass index between the two groups. The meta-analysis suggested that pregnant women who were obese (OR:1.37;95%CI:1.15 to 1.62), hypertensive (OR:2.07;95%CI:1.38 to 3.10) or had a respiratory disorder (OR:1.64;95%CI:1.25 to 2.16), were more likely to be symptomatic when infected with SARS-CoV-2. Pregnant women with Black (OR:1.48;95%CI:1.19 to 1.85) or Asian (OR:1.64;95%CI:1.23 to 2.18) ethnicity were more likely to be symptomatic while those with White ethnicity (OR:0.63;95%CI:0.52 to 0.76) were more likely to be asymptomatic. Cesarean-section delivery (OR:1.40;95%CI:1.17 to 1.67) was more likely amongst symptomatic pregnant women. The mean birthweight(g) (MD:240.51;95%CI:188.42 to 293.51), was significantly lower, while the odds of low birthweight (OR:1.85;95%CI:1.06 to 3.24) and preterm birth (< 37 weeks) (OR:2.10;95%CI:1.04 to 4.23) was higher amongst symptomatic pregnant women. Symptomatic pregnant women had a greater requirement for maternal ICU admission (OR:13.25;95%CI:5.60 to 31.34) and mechanical ventilation (OR:15.56;95%CI:2.96 to 81.70) while their neonates had a higher likelihood for Neonatal Intensive Care Unit admission (OR:1.96;95%CI:1.59 to 2.43). The management strategies in the included studies were poorly discussed, hence could not be analyzed.ConclusionThe evidence suggests that the presence of risk factors (co-morbidities and ethnicity) increased the likelihood of pregnant women being symptomatic. Higher odds of complications were also observed amongst symptomatic pregnant women. However, more adequately conducted studies with adjusted analysis and parallel comparison groups are required to reach conclusive findings.

Population birth outcomes and experiences of expectant mothers during the COVID-19 pandemic in Wales: a mixed methods study

BackgroundPregnancy can be a stressful time and the COVID-19 pandemic is thought to have heightened maternal stress. This study aimed to investigate the effect of the COVID-19 pandemic on population birth outcomes, uptake of primary immunisations, and expectant mothers' experiences of pregnancy in Wales. MethodsIn this mixed methods study we analysed stillbirths, prematurity, birthweight and caesarean section births before (2016–19) and during (2020) the pandemic using national routine anonymised data held in the Secure Anonymised Information Linkage Databank. Uptake of the first three scheduled primary immunisations were compared between 2019 and 2020. Immunisations were extracted from the routinely collected data in the National Community Child Health Database. We compared percentages between years the ran χ2 with Yates correction for the three percentages given. Expectant mothers (aged ≥16 years) in Wales completed an online survey about their experiences of pregnancy during the pandemic. Inclusion criteria was being aged 16 years or older and living in Wales. The qualitative survey data was analysed using codebook thematic analysis. Ethical approval was granted by Swansea University Ethics Committee and each participant provided written consent before answering any survey questions. FindingsThere was no significant difference between annual outcomes including gestation and birthweight, stillbirths, and caesarean sections for infants born in 2020 compared with 2016–19. Difference in gestation (moderate to late preterm difference –0·26%, 95% CI –0·52% to –0·01%). Difference in low birthweight 0·13% (0·00% to 0·26%). Difference in stillbirths –0·01% (–0·02% to 0·00%). Difference in caesarean sections –0·42% (–1·13% to 0·29%). There was an increase in late-term births (≥42 weeks gestation) during the first lockdown (odds ratio [OR] 1·28, p=0·019) and a decrease in moderate to late preterm births (32–36 weeks gestation) during the second lockdown (OR 0·74, p=0·001). Fewer babies were born in 2020 (n=29 031) compared with 2016–19 (n=32 582; mean [SD 1561]). All babies received their immunisations in 2020, but there were minor delays in the timings of vaccines. Those vaccinations due at 8-weeks were 8% less likely to be on time (within 28 days) and, at 16-weeks, they were 19% less likely to be on time. The pandemic had a negative effect on the mental health of 151 (72%) of 211 survey respondents, who reported feeling anxious, nervous, or depressed; this finding was associated with attending scans without their partner, giving birth alone, and minimal contact with midwives. InterpretationThe COVID-19 pandemic had a negative effect on mothers' experiences of pregnancy; however, population data suggests that this did not translate to adverse birth outcomes for babies born during the pandemic. FundingHealth Care Research Wales

Association of low birthweight and premature birth with hypertensive disorders in pregnancy: a systematic review and meta-analysis.

Growing evidence suggests that women born preterm or small have an increased risk of experiencing hypertensive disorders during pregnancy; however, a quantitative summary of the evidence on this issue is unavailable. We aimed to systematically review the literature to describe the association between being born preterm, low birthweight (LBW), or small for gestational age (SGA), and future gestational hypertension, preeclampsia, or eclampsia. We searched the MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and ICTRP databases. We included all cohort and case-control studies examining the association between LBW, preterm birth, or SGA and hypertensive disorders in pregnancy. We pooled the odds ratios and 95% confidence intervals using the DerSimonian and Laird random-effects model. We assessed the certainty of evidence for each outcome using the Grading of Recommendations, Assessment, Development, and Evaluation criteria. Eleven studies were identified, totalling 752 316 participants. Being born preterm, LBW, or SGA was associated with gestational hypertension [pooled odds ratio (OR), 1.31; 95% confidence interval (CI) 1.15-1.50; moderate certainty of evidence] and preeclampsia (pooled OR, 1.35; 95% CI 1.23-1.48; moderate certainty of evidence). No study measured eclampsia as an outcome. Women born preterm, LBW, or SGA have an increased risk of gestational hypertension and preeclampsia. The course of the mother's own birth might be used to identify women at risk of gestational hypertension and preeclampsia.

68Maternal exposure to PM2.5 from a severe smoke event and birth outcomes in Victoria, Australia

Abstract Background The 2014 Hazelwood coal mine fire was an unprecedented six-week severe smoke event in the Latrobe Valley, southeastern Australia. We aimed to determine whether maternal exposure to fine particulate matter (PM2.5) attributable to the event was associated with adverse fetal growth or maturity, including birthweight, small for gestational age, term low birthweight or preterm birth. Methods A cohort of babies born within the affected region was defined used administrative perinatal data. Maternal average and peak PM2.5 was assigned to residential address at time of delivery using a chemical transport model. Maternal, infant, meteorological and temporal variables were included in final linear and log-binomial regression models. Results 3,591 singleton livebirths were included; 763 were exposed in utero. Average PM2.5 exposure was 4.4 µg/m3 (IQR 2.1 µg/m3); average peak was 45.0 µg/m3 (IQR 35.1 µg/m3). No association between PM2.5 and fetal growth or maturity was observed. Gestational diabetes mellitus was an effect modifier in the relationship; babies of exposed gestational diabetic mothers were 97 grams heavier per 10 µg/m3 increase in average PM2.5 exposure (95%CI 74, 120 grams), compared to mothers without gestational diabetes. Conclusions Maternal PM2.5 exposure from a smoke event was not associated with adverse fetal growth or maturity. There was a trophic response amongst babies of mothers with gestational diabetes. Key messages Babies born to mothers with gestational diabetes may be more susceptible to the effects of smoke events on birthweight.

PREGNANCY OUTCOMES AFTER PGT-A BY RACE: MISCARRIAGE, LOW BIRTHWEIGHT, AND PRETERM BIRTH

To evaluate the associations between race, PGT-A use, and rates of miscarriage, low birthweight, and preterm birth. This was a retrospective cohort study using national Society for Assisted Reproductive Technology (SART) data from 2014-2016. Autologous first embryo transfers in women 18-50 years-old were included. Embryo transfer type was categorized as PGT-A tested, fresh untested, and thawed untested. Only cycles resulting in singleton gestations were included for analyses on preterm birth and low birthweight. Low birthweight was defined as <2,500 grams. Age groups were defined as: 18-34, 35-37, 38-40, 41-50 yrs. Of the 110,843 first embryo transfers, 64,331 (58%) resulted in a clinical pregnancy and 53,880 (49%) resulted in a live birth of at least one infant. Miscarriage rate was significantly lower from cycles using PGT-A (13.5%) compared to both fresh (14.7%) and frozen (17.1%) untested embryos (p<0.0001). African American women had the highest miscarriage rates regardless of PGT-A use. Whereas white women had a 13.5% rate of miscarriage after PGT-A, African American women had a 22.4% rate (p<0.0001). Hispanic women had a slightly higher rate of miscarriage (16.9%), but this difference was not statistically significant. Among all cycles, miscarriage rates increased with increasing age, but this was less pronounced with PGT-A use. In multivariate regression for PGT-A cycles, only the oldest age group (41-50) had a statistically significant increased risk of miscarriage compared to the youngest group (OR 1.25; 95% CI 1.06-1.48, p=0.009). African American women had 80% greater odds of miscarriage (OR 1.80; 95% CI 1.34-2.42, p=0.0001) than white women. Among 42,811 singleton live births, preterm birth was lower for cycles after PGT-A (16.6%) than for either fresh (18.3%) or frozen (17.4%) untested embryo transfers (p=0.01). Among women using PGT-A, African American women had the highest rate of preterm birth (24%), followed by Hispanic women (23%). Cycles after PGT-A use were less likely to have a low birthweight infant (6.6%) than either fresh (9.8%) or frozen (7.8%) untested cycles (p<0.001). Among cycles after PGT-A use, African American women had the highest rate of low birthweight infants (13%), over twice that of white women (5.9%) (p<0.001). PGT-A use is associated with reduced rates of miscarriage, preterm birth, and low birthweight infants. However, African American women using this technology still had significantly higher rates of these pregnancy outcomes. Limitations of this study include the fact that approximately 40% of women had unknown race; it is unknown what proportion of prematurity was iatrogenic; and that medical comorbidities predisposing to prematurity and low birthweight are unknown.

Birth Outcomes among Descendants of Foreign-Born and US-Born Women in California: Variation by Race and Ethnicity.

This study quantifies the magnitude and persistence of differences in adverse birth outcomes between descendants of foreign-born and US-born women by race/ethnicity. Using 1978-2015 California birth records, I linked records of infants to those of their mothers to create an intergenerational sample (N = 501,323second generation mothers and 633,102 third generation daughters). Prevalence of low birthweight and preterm birth were calculated in both generations by race/ethnicity, and foreign-born status. An initial foreign-born advantage in birth outcomes is present among most racial/ethnic groups with the exception of foreign-born Asian women. In the subsequent generation, the foreign-origin advantage diminishes for most groups and a foreign-origin disadvantage in low birthweight emerges for descendants of Asian women. Findings largely persist after adjustment for sociodemographic and healthcare-related characteristics. These results underscore the importance of disaggregating by race, ethnicity, and foreign origin when possible to better understand perinatal health disparities in the population.

Community Effects of Police-Related Deaths: Associations With Low Birthweight Births and Poverty Among US Counties.

Police-related deaths are a public health problem; however, their effects on community-level reproductive health outcomes remain largely unexplored. Among US counties with populations >100,000 (N = 580), we examined the longitudinal association between police-related deaths and rates of low birthweight (LBW) (<2,500 grams) deliveries, with counties stratified by quartiles of poverty. In the two lowest poverty quartiles, two or more police-related deaths were associated with a 5% (incidence rate ratio [IRR]: 1.05, 95% confidence interval [CI]: 1.02, 1.09) and 10% (IRR 1.10, 95% CI: 1.05, 1.15) higher rate of LBW births, respectively. The effect was not significant in the two highest poverty quartiles. No counties are "immune" from the important effects of police-related deaths and therefore the public health importance of police violence is a ubiquitous one regardless of social class or position.

P331 The safety of tioguanine exposure during pregnancy: a case series of seventy-three pregnancies

Abstract Background Azathioprine and mercaptopurine exposure during conception and pregnancy has been considered safe in patients with inflammatory bowel disease (IBD). Its use is not associated with a higher risk of preterm birth or low birthweight. Data on the safety of tioguanine, an alternative thiopurine-derivate, in pregnant IBD patients is limited. In a small case series, tioguanine appeared safe for both mother and fetus. In this study, we describe the teratogenicity and safety of tioguanine during pregnancy in a large group of IBD patients. Methods We performed a preliminary analysis of our ongoing multicenter descriptive case series of female IBD patients who were treated with tioguanine at some point during their pregnancy. Data regarding disease and medication history, pregnancy course and neonatal outcomes, such as preterm birth, miscarriage, birthweight, Apgar scores and congenital abnormalities were collected by the treating physician. Results Seventy-three pregnancies, including three twin pregnancies were collected. Most women (80%) had Crohn’s disease and the mean age during delivery was 31 years (range 21-42). Tioguanine was used throughout the entire pregnancy in 89% with a median daily dose of 20 mg. Five (6.8%) of these pregnancies resulted in a miscarriage, all within the first 13 weeks. No congenital abnormalities were reported in all seventy-one live born children. In the singleton pregnancies the median birthweight was 3375 gram (IQR 3075-3739, N=61, 4 missing values) with a median gestational age of 39.0 weeks (IQR 38.3-40.0, N=61). Four children (6.5%) were born prematurely (&amp;lt;37 weeks). Two of them were born after a spontaneous onset of labor with respectively 33 + 6 and 35 + 6 weeks, while in the other two labor was induced due to a placental abruption (32 + 1 weeks) or HELLP syndrome (31 + 4 weeks). Three children (4.9%) had a low birthweight (&amp;lt;2500 gram), all of them born prematurely, and five patients (8.3%, N=60, 5 missing values) were born small for gestational age (&amp;lt;10th percentile). The median Apgar score after 1 and 5 minutes was respectively 9 (IQR 8-9, N=58) and 10 (IQR 9-10, N=59). Two neonates (3.4%), one born pre-and dysmature and the other a premature second-born twin, had an Apgar score (&amp;lt;7) after 5 minutes. Conclusion In this large case-series, tioguanine exposure during pregnancy was not associated with an increased risk of congenital abnormalities, low birthweight or preterm birth in IBD patients. These data support the safe use of tioguanine during pregnancy in IBD.

Effects of maternal exposure to fine particulate matter on birth weight in 16 counties across China: a quantile regression analysis

The adverse effects of air pollution during pregnancy have been studied intensively, but mainly utilizing linear and logistic models, which generally yield little information about how air pollution may change the distribution of birth weight in populations. We aimed to examine the effects of fine particulate matter (PM2.5) on quantiles of birth weight, and if effects were heterogeneous in different populations and regions. We used a prospective cohort study of 196 283 singleton term live births from 16 counties across China during 2014–2018. PM2.5 exposure for full gestation, each trimester and last gestational month were assessed by Inverse Distance Weighting interpolation. Linear and quantile regression were conducted to estimate associations between PM2.5 exposure and mean birth weight, as well as birth weight distribution, with birthweight z-score as the main outcome. Stratified analyses and Cochran Q tests were conducted by maternal and geographical characteristics. Each 10 µg m−3 increase in average PM2.5 over the entire pregnancy was associated with reduced birthweight z-score (−0.010, 95% CI: −0.015, −0.005) and birth weight (−3.21 g, 95% CI: −5.27, −1.15). In quantile regression, more pronounced effects were observed in lower and intermediate quantiles, with a decrease of 0.021 (95% CI: 0.033, 0.009) and 0.009 (95% CI: 0.015, 0.002) in the 5th and 50th quantiles of birthweight z-score, respectively. Additionally, we observed stronger associations among well-educated, migrant and primiparous mothers as well as in coastal areas. Maternal exposure to PM2.5 was associated with reduction in birth weight, especially for those with very low birth weight. Well-educated, migrant and primiparous mothers, as well as births in coastal areas may be more sensitive to PM2.5 in our study population. The results may be relevant to targeted public health interventions to reduce maternal exposure to air pollution.

Comparison of adverse birth outcomes among HIV-infected and HIV-uninfected women delivering in high and low risk settings in the era of universal ART in Malawi: a registry study

ABSTRACT Background: Recent studies show that ART is associated with an adverse birth outcome in HIV-infected women. Aim: To compare rates of low birthweight (LBW) and preterm birth (PTB) between HIV-infected women receiving lifelong ART and HIV-uninfected women giving birth in low- and high-risk settings in Malawi. Methods: This observational, registry study was conducted from January 2016 to August 2017 in one large, tertiary referral hospital and four primary healthcare (PHC) facilities in Blantyre, Malawi. Women who delivered singleton live births or stillbirths of ≥20 weeks gestation were included in the analysis. Descriptive and stratified analyses were conducted using χ2 tests and multivariable logistic models to control for maternal age, gravidity and health facility. Results: A total of 14,233 births were included in the analysis (7715 from the tertiary hospital and 6518 from PHC facilities). In the univariable analysis, there were no differences in rates of LBW (6.7% vs 6.4%) and PTB (42.5% vs 42.0%) between HIV-infected and -uninfected women delivering in PHC facilities. However, differences in LBW were significantly higher in HIV-infected women in multivariable analysis (LBW aOR 1.40, 95% CI 1.01–1.95). Rates of LBW and PTB were significantly higher in HIV-infected women than in uninfected women delivering at the tertiary hospital (LBW 17.6% vs 13.2%, aOR 1.53, 95% CI 1.27–1.85; PTB 28.2% vs 24.9%, aOR 1.37, 95% CI 1.17–1.60) Conclusion: Rates of adverse birth outcomes are significantly higher in HIV-infected women than in HIV-uninfected women, and this is more apparent in high-risk hospital settings than in low-risk PHC settings.

Gestational carrier pregnancy outcomes from frozen embryo transfer depending on the number of embryos transferred and preimplantation genetic testing: a retrospective analysis

To compare gestational age, birth weight (BW), and live birth rates in gestational carriers (GC) after the transfer of 1 or 2 frozen embryo(s) with or without preimplantation genetic testing for aneuploidy (PGT-A), with the understanding that several social and economic factors may motivate intended parents to request the transfer of 2 embryos and/or PGT-A when using a GC. Retrospective cohort study SETTING: An assisted reproductive technology practice. All frozen blastocyst transfers with GCs from 2009-2018. One or 2 embryo frozen embryo transfers with and without PGT-A. Live birth, preterm birth, and low BW. A total of 583 frozen embryo transfer cycles with vitrified high-grade blastocysts (grade BB or higher) to GCs were analyzed. Although the live birth rate was significantly greater in frozen embryo transfers with 2 embryos, after single embryo transfer (SET), the mean gestational age and BW of live births were statistically significantly greater than those of double embryo transfer (DET). The rate of multiple births was 1.9% for SET compared to 20.0% for DET per transfer. Only 3.8% of live births from SET experienced low BW and 0.6% had very low or extremely low BW. By comparison, 12.5% of DET live births were low BW and 5% were very low BW. After SET, 13.4% of live births were preterm, compared with 40% in DET. The analysis also included a total of 194 transfers with PGT-A compared to 389 cycles without. Overall, live births per transfer were not significantly different between these latter 2 subgroups. Frozen embryo transfer cycles in GCs with DET were associated with more preterm births and lower birth weights compared with those of SET. Intended parents and GCs should be counseled that DET is associated with greater risks of adverse pregnancy and perinatal outcomes, which mitigates higher live birth rates. The use of PGT-A did not appear to improve the live birth rate.

Risk of intellectual disability and maternal history of spontaneous abortion: a nationwide cohort study.

To investigate the association between a maternal history of spontaneous abortion and intellectual disability in children. This cohort study included 1778786 children (913 340 males, 865 085 females, 361 missing data; mean age 15y 2mo, SD 8y 11mo, range birth to 40y) born in Denmark between 1977 and 2016. Cox proportional hazard regression was used to estimate the hazard ratios (HRs) of intellectual disability. The overall HR of intellectual disability for children with a maternal history of spontaneous abortion was 1.17 (95% confidence interval [CI] 1.12-1.22) and the risk for multiple spontaneous abortions (HR=1.30, 95% CI 1.20-1.40) was higher than for a single spontaneous abortion (HR=1.13, 95% CI 1.07-1.18). When only cases of inpatient intellectual disability were included, the estimates increased slightly: the overall HR was 1.22 (95% CI 1.12-1.32), the HR for multiple spontaneous abortions was 1.37 (95% CI 1.20-1.58), and the HR for a single spontaneous abortion was 1.17 (95% CI 1.07-1.28). The risks were similar regardless of whether spontaneous abortion occurred before or after the index delivery. Estimates were nearly unchanged after adjusting for preterm birth, low birthweight, or Apgar score. Children born to mothers with spontaneous abortion, especially multiple spontaneous abortions, may be at a higher risk of intellectual disability in later life, regardless of whether spontaneous abortion occurred before or after the index delivery. The findings have clinical implications for targeted early intervention of children with intellectual disability. What this paper adds A maternal history of spontaneous abortion was associated with a risk of intellectual disability in offspring. The risk was higher in children whose mothers previously had multiple spontaneous abortions. Similar risks were observed regardless of whether spontaneous abortion occurred before or after childbirth.

Risks of nonchromosomal birth defects, small-for-gestational age birthweight, and prematurity with in vitro fertilization: effect of number of embryos transferred and plurality at conception versus at birth

Excess embryos transferred (ET) (> plurality at birth) and fetal heartbeats (FHB) at 6 weeks' gestation are associated with reductions in birthweight and gestation, but prior studies have been limited by small sample sizes and limited IVF data. This analysis evaluated associations between excess ET, excess FHB, and adverse perinatal outcomes, including the risk of nonchromosomal birth defects. Live births conceived via IVF from Massachusetts, New York, North Carolina, and Texas included 138,435 children born 2004-2013 (Texas), 2004-2016 (Massachusetts and North Carolina), and 2004-2017 (New York) were classified by ET and FHB. Major birth defects were reported by statewide registries within the first year of life. Logistic regression was used to estimate adjusted odds ratios (AORs) and 95% CIs of the risks of a major nonchromosomal birth defect, small-for-gestational age birthweight (SGA), low birthweight (LBW), and preterm birth (≤36 weeks), by excess ET, and excess ET + excess FHB, by plurality at birth (singletons and twins). In singletons with [2 ET, FHB =1] and [≥3 ET, FHB=1], risks [AOR (95% CI)] were increased, respectively, for major nonchromosomal birth defects [1.13 (1.00-1.27) and 1.18 (1.00-1.38)], SGA [1.10 (1.03-1.17) and 1.15 (1.05-1.26)], LBW [1.09 (1.02-1.13) and 1.17 (1.07-1.27)], and preterm birth [1.06 (1.00-1.12) and 1.14 (1.06-1.23)]. With excess ET + excess FHB, risks of all adverse outcomes except major nonchromosomal birth defects increased further for both singletons and twins. Excess embryos transferred are associated with increased risks for nonchromosomal birth defects, reduced birthweight, and prematurity in IVF-conceived births.

931 Maternal and neonatal outcomes associated with vasa previa resolution during the antepartum period

In recent years, the phenomenon of “resolved” vasa previa has been increasingly described when vasa previa (VP) is detected on ultrasound in the midtrimester with a resolution rate as high as 20-26%. There is little information on the obstetrical outcomes associated with resolved VP. Our objective was to describe obstetrical and neonatal outcomes in women with resolved VP and compare them to women who have persistent VP. This was a multi-center descriptive and retrospective cohort study of patients diagnosed prenatally with VP on transvaginal ultrasound in the NYC MFM Research Consortium centers between 2012 and 2018. The primary outcome was gestational age (GA) at delivery. Other outcomes evaluated included mode of delivery, birthweight, NICU admission, and preterm birth. Data were analyzed using Mann-Whitney U test and Fisher exact test with p<0.05 defined as significance. 165 pregnancies with VP were included, of which 16 were twin gestations. 43 VP cases (26.1%) including one twin gestation were noted to resolve on subsequent ultrasound, of which 6 were lost to follow up. Pregnancies with resolved VP had a higher median GA at delivery, lower rate of preterm birth <37 weeks, and lower rate of cesarean delivery. There was no difference in rate of preterm birth <32 weeks (Table 1). Neonatal data was available on 131 newborns. In cases of resolved VP, neonates had a higher median birthweight and lower rate of NICU admission. There were no significant differences in rates of neonatal blood transfusion or neonatal death (Table 2). Resolved VP is associated with later GA at delivery, lower rate of cesarean delivery, and improved neonatal outcomes. However, it is not associated with a reduction in preterm birth prior to 32 weeks. The observed preterm birth rate in the resolved group of 16% raises concern that resolved VP may be a risk factor for preterm birth and merits further investigation. Once VP is diagnosed, surveillance for VP resolution should be performed as resolution has important implications for obstetrical and neonatal outcomes.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

BIRTH WEIGHT AND LITTER BIRTH WEIGHT IN YANKASA SHEEP: ENVIRONMENTAL FACTORS AND HERITABILITY ESTIMATES

A study was conducted to examine the influence of five environmental factors on birthweight (BWT) and litter birth weight (LBWT) and to obtain heritability estimates for both traits in Yankasa sheep. Records of 2490 lambs sired by 133 rams and 1225 lambs sired postnatally by 120 rams from 1983-1993 at Shika were analysed for BWT and LBWT, respectively. The Yankasa flock was semi-intensively l managed in an accelerated lambing programme. Least-squares means were 2.48±0.03 kg and 3.57±0.03 kg for BWT and LBWT, respectively. All five environmental LBWT in factors considered (parity, sex, type of birth, Yankasa sheep High season and year of birth) were highly significant (P&lt;0.001) for both traits. Lambs from multiparous ewes had higher body weights than lambs from primiparous ewes. Likewise, rainy-season-born lambs were heavier than dry-season-born lambs. Ram lambs were consistently heavier than ewe lambs for both traits, their superiority also being reflected in higher LBWT for mixed sexes. Single born lambs. were, superior to single lambs for LBWT. Heritability estimates by paternal half sib analysis, after appropriately adjusting data for the fixed effects,were 0.410, 0.8 and 0.12±0.07 for BWT and LBWT, ; respectively. These results indicate that high genetic response is expected from selection for BWT, while low response is expected for LBWT. Adjustment for environmental effects is necessary to enhance the accuracy of selection for superior individuals in terms of gene expression for these traits.

Is there Evidence for Vitamin K Prophylaxis in Pregnant Women taking Anticonvulsant Drugs?

Purpose: The objective of this study was to examine the need of vitamin K prophylaxis in women with epilepsy (WWE) taking anticonvulsant drugs (AED) during pregnancy to prevent neonatal bleeding. Patients and methods: The study population (n=1037) consisted of two study groups: i) the epilepsy group including all neonates of WWE (n=51) taking AED of the Innsbruck EURAP register. Twenty-four of the 51 were taking enzyme-inducing AED (EIAED). ii) the control group of 986 newborns not exposed to AED. Results: The two study groups did not differ regarding hemorrhagic complications in newborns. None of the newborns of WWE taking AED showed neonatal bleeding. Hemorrhagic complications were more prevalent in newborns with low birth weight (p<0.01) and in multiple birth (p=0.02). Conclusion: Neonates exposed to AED, enzyme-inducing and non-enzyme-inducing, were not at a higher risk for hemorrhagic complications compared to unexposed newborns. Birth-weight and multiple birth - not AED - should be considered as risk factors of neonatal bleeding.

Going Beneath the Surface: Petroleum Pollution, Regulation, and Health

This paper quantifies the health impacts of petroleum leaks from underground storage tanks, the effectiveness of tank regulation, and the role of information as a policy tool in the same setting. Exposure to a leaking underground storage tank during gestation increases both the probability of low birthweight and preterm birth by 7–8 percent. Compliance with regulations requiring the adoption of preventative technologies mitigated the entire effect of leak exposure on low birthweight, and information increased avoidance and moving among highly educated mothers. Back-of-the-envelope calculations suggest the health benefits of preventative regulations exceed the upgrade cost to facilities. (JEL I12, K32, L71, L78, Q35, Q51, Q53)

Methylparaben in Meconium and Risk of Maternal Thyroid Dysfunction, Adverse Birth Outcomes, and Attention-Deficit Hyperactivity Disorder

Background Parabens are detected ubiquitously in human urine samples, but the effects of prenatal exposure are unclear, partially due to inadequate exposure assessment in maternal urine, which may fail to capture fetal exposure. We examined the association of meconium methylparaben detection with preterm birth, gestational age, birthweight, maternal thyroid hormones, and child attention-deficit hyperactivity disorder (ADHD) at 6-7 years. Methods Methylparaben was measured in meconium with ultraperformance liquid chromatography mass spectrometry and dichotomized (detect/non-detect) for 345 children in the Gestation and the Environment cohort in Sherbrooke, Quebec, Canada, Birth outcomes and maternal thyroid hormones (T3, T4, and thyroid stimulating hormone [TSH]) at &lt;20 weeks gestation were measured at the Centre Hospitalier Universitaire de Sherbrooke. ADHD diagnosis at age 6-7 was determined at follow-up or from medical records. Associations were estimated with logistic and linear regressions, and the potential for mediation by birthweight and preterm birth of the effect of methylparaben on ADHD was modeled with causal mediation analysis. Results Meconium methylparaben detection was associated with increased odds of preterm birth (odds ratio [OR]=4.81; 95% CI [2.29, 10.10]), decreased gestational age (beta [β]=-0.61 weeks; 95% CI [-0.93, -0.29]) and decreased birthweight (β=-0.12 kilograms; 95% CI [-0.21, -0.03]). Associations were also found with decreased maternal TSH (relative concentration [RC]=0.76; 95% CI [0.58, 0.99]) and total T3 (RC=0.84; 95% CI [0.75, 0.96]), but increased total T4 (RC=1.10; 95% CI [1.01, 1.19]). Mothers of infants with detectable meconium methylparaben had increased odds of hypothyroxinemia (OR=2.50, 95% CI [1.01, 6.22]), and children were more likely to be diagnosed with ADHD at age 6-7 (OR=2.33, 95% CI [1.45, 3.76]). Preterm birth and birthweight mediated 20% and 13% of the effect of methylparaben on ADHD respectively. Conclusions This adverse association between methylparaben and ADHD, partially mediated by birth outcomes, warrants further research into fetal methylparaben exposure.

Analyzing temporal trends and spatial patterns in adverse birth outcomes in Massachusetts from 2000–2014

This study explores temporal trends and spatial patterns in adverse birth outcomes (ABO) in the state of Massachusetts from 2000 to 2014. ABO include low birthweight (<2500 g) and preterm births (gestational age <37 weeks). This research evaluates if there are areas in Massachusetts that have experienced statistically significant increases or decreases in ABO throughout the study period. Birth data was obtained from the Massachusetts Department of Public Health and only singleton, live births were included for the analysis. The data were aggregated to census tracts, and the total number of births and the number of ABOs were calculated for each census tract for each year. In total, 1478 census tracts were included in this analysis. Trends and patterns of ABO were evaluated using the Space Time Cube and the Mann-Kendall statistic and a multiple linear regression was conducted to identify potential associations between socioeconomic factors and prevalence of ABO. Results showed that there were associations between the socioeconomic indicators and the ABO rate (particularly educational attainment, income, and diversity) though there were no conclusive racial disparities present throughout the state or 15-year study period. Results of this study can be used to identify areas that are experiencing an increase in ABO to potentially allow for more effective, targeted intervention methods.