Background: We monitored exposure to fine particulates (PM2.5), ozone, nitrogen dioxide (NO2), and ambient temperature for pregnant women with and without asthma. Methods: Women (n = 40) from the Breathe—Well-Being, Environment, Lifestyle, and Lung Function Study (2015–2018) were enrolled during pregnancy and monitored for 2–4 days. Daily pollutants were measured using personal air monitors, indoor air monitors, and nearest Environmental Protection Agency’s stationary monitors based on GPS tracking and home address. Results: Personal-monitor measurements of PM2.5, ozone, and NO2 did not vary by asthma status but exposure profiles significantly differed by assessment methods. EPA stationary monitor-based methods appeared to underestimate PM2.5 and temperature exposure and overestimate ozone and NO2 exposure. Higher indoor-monitored PM2.5 exposures were associated with smoking and the use of gas appliances. The proportion of waking-time during which personal monitors were worn was ~56%. Lower compliance was associated with exercise, smoking, being around a smoker, and the use of a prescription drug. Conclusions: Exposure did not vary by asthma status but was influenced by daily activities and assessment methods. Personal monitors may better capture exposures but non-compliance merits attention. Meanwhile, larger monitoring studies are warranted to further understand exposure profiles and the health effects of air pollution during pregnancy.
Chronic air pollution exposure increases risk for hypertensive disorders of pregnancy, but the effect of acute air pollution exposure on blood pressure during pregnancy is less well known. We studied 151,276 singleton term deliveries from the Consortium on Safe Labor (2002–2008) with clinical blood pressure measured at admission to labor/delivery and diagnoses of hypertensive disorders collected from electronic medical records and hospital discharge summaries. Air pollution exposures were estimated for the admission hour and the 4 hours preceding admission using a modified version of the Community Multiscale Air Quality models and observed air monitoring data. Blood pressure was categorized as normal; high normal; and mild, moderate, or severe hypertension based on pregnancy cut points. Adjusted ordinal logistic regression estimated the odds of women having a higher admission blood pressure category as a function of air pollutant, hypertensive disorders, and their interaction effect. Odds of high blood pressure at admission to labor/delivery were increased in normotensive women after exposure to nitrogen oxides (by 0.2%/5 units), sulfur dioxide (by 0.3%/1 unit), carbon monoxide and several air toxics (by 3%–4%/high exposure). The effects were often similar or stronger among women with gestational hypertension and preeclampsia. Exposure to particulate matter <10 μm increased odds of high blood pressure in women with preeclampsia by 3%/5 units. Air pollution can influence admission blood pressure in term deliveries and may increase likelihood of preeclampsia screening at delivery admission.
<p dir="ltr">Objective: Gestational diabetes mellitus (GDM) increases the risk of fetal overgrowth, as measured by two-dimensional (2D) ultrasonography. Whether fetal 3D soft tissue and organ volumes provide additional insight into fetal overgrowth is unknown. </p><p dir="ltr">Research Design & Methods: We prospectively evaluated longitudinal 3D fetal body composition and organ volumes in a diverse US singleton pregnancy cohort (2015-2019). Women were diagnosed with GDM, impaired glucose tolerance (IGT), or normal glucose tolerance (NGT). Up to five 3D ultrasound scans measured fetal body composition and organ volumes; trajectories were modeled using linear mixed models. Overall and weekly mean differences in fetal 3D trajectories were tested across glycemic status, adjusted for covariates.</p><p dir="ltr">Results: In this sample (N=2427), 5.2% of women had GDM and 3.0% had IGT. Fetuses of women who developed GDM, compared to NGT, had larger fractional arm and fractional fat arm volumes from 26-35 weeks, smaller fractional lean arm volume from 17-22 weeks, and larger abdominal area from 24-40 weeks. Fetuses of women with IGT had similar growth patterns, but manifested later in gestation and with larger magnitudes, and had larger fractional lean arm volume. No overall differences were observed among thigh or organ volumes across glycemic status.</p><p dir="ltr">Conclusions: Body composition differed in fetuses of GDM pregnancies, including larger arm and abdominal measures across the second and third trimesters. Patterns were similar in IGT pregnancies except occurred later in gestation and with larger magnitudes. Future research should explore how lifestyle and medication may alter fetal fat accumulation trajectories among hyperglycemic pregnancies. </p>
OPS 01: Understudied environmental health issues, Room 412, Floor 4, August 26, 2019, 10:30 AM - 12:00 PM Background/Aim: Although ecological studies have observed relationships between ambient temperature and fertility, it is unclear whether these observations are due to effects on physiology and/or through behavior and whether individual-level factors may bias findings. In the LIFE study, a preconception cohort of couples attempting pregnancy, we evaluated the relationship of temperature with both pregnancy and intercourse, a key behavioral mediator. Methods: 500 couples from Michigan and Texas with geocoded addresses were followed for up to 12 months attempting pregnancy and reported start of menses, day of ovulation, pregnancy status and daily intercourse for each menstrual cycle. The Weather Research Forecasting model estimated daily temperature and humidity at participants' residences. Temperature was modeled per 5 degrees Celsius and non-linear trends assessed using natural cubic splines. Generalized estimating equations accounted for multiple observations per participant, adjusting for relative humidity, season, study site, menstrual cycle of follow-up and maternal characteristics. Results: Mean temperature was 8.7 (SD=9.3; Min=-6.3, Max=26.1) degrees Celsius in Michigan and 21.9 (SD=5.6; Min=9.4, Max=30.7) in Texas. No non-linear trends were observed between temperature and fecundability or intercourse. Average temperature during both the fertile window and implantation was related to menstrual-cycle probability of pregnancy in unadjusted models (RR=1.05, 95% CI=1.00-1.11 and RR=1.05, 95% CI=1.00-1.11); however, estimates were attenuated after adjustment (RR=1.01, 95% CI=0.96-1.05 and RR=1.01, 95% CI=0.95-1.07). Higher temperature was associated with a small increase in daily probability of intercourse within (RR=1.03, 95% CI=1.00-1.06) but not outside (RR=1.00, 95% CI=0.97-1.03) the fertile window. No heterogeneity was observed by study site or season. Conclusions: In a population attempting pregnancy and exposed to moderate temperatures, temperature and fecundability were not associated after adjustment. There was a modest increase in intercourse with higher temperatures during the fertile window. Studies that observe relationships between temperature and fecundability should consider intercourse patterns as a potential mediator.
Although ambient air pollution may increase hypertension risk through endothelial damage and oxidative stress, evidence is inconsistent regarding its effect on hypertension in pregnancy. Prior research has evaluated a limited scope of pollution species and often not differentiated preeclampsia, which may have a placental origin, from gestational hypertension. Among 49 607 women with at least 2 singleton deliveries in the Eunice Kennedy Shriver National Institute of Child Health and Human Development Consecutive Pregnancies Study (2002–2010), we estimated criteria pollutant and volatile organic compound levels during pregnancy using Community Multiscale Air Quality models and abstracted gestational hypertension and preeclampsia diagnoses from medical records. Generalized estimating equations accounted for repeat pregnancies and adjusted for ambient temperature and maternal age, race/ethnicity, body mass index, smoking, alcohol, parity, insurance, marital status, and asthma. Air pollution levels were low to moderate (eg, median 41.6 ppb [interquartile range, 38.9–43.7 ppb] for ozone and 35.1 ppb [28.9–40.3 ppb] for nitrogen oxides). Higher levels of most criteria pollutants during preconception and the first trimester were associated with lower preeclampsia risk, while higher second-trimester levels were associated with greater gestational hypertension risk. For example, an interquartile increase in first-trimester carbon monoxide was associated with a relative risk of 0.88 (95% CI, 0.81–0.95) for preeclampsia and second-trimester carbon monoxide a relative risk of 1.14 (95% CI, 1.07–1.22) for gestational hypertension. Volatile organic compounds, conversely, were not associated with gestational hypertension but consistently associated with higher preeclampsia risk. These findings further suggest air pollution may affect the development of hypertension in pregnancy, although differing causes of preeclampsia and gestational hypertension may alter these relationships.
