Longitudinal assessment of maternal depression and early childhood asthma and wheeze: Effect modification by child sex.

BACKGROUND: Studies report associations between maternal mental health and adverse respiratory outcomes in children; however, the impact of timing and duration of maternal distress remains understudied. We sought to longitudinally examine associations between maternal depression and childhood asthma and wheeze, and explore sex differences. METHODS: Maternal depression (n = 601) was assessed using the Edinburgh Depression Scale questionnaire, dichotomized at a clinically relevant cutoff (>12) (a) during pregnancy, (b) postpartum, and (c) postpartum and subsequent time points postnatally (recurrent depression). Report of wheeze in the past 12 months (current wheeze) and asthma were obtained using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire at 48 and 72 months. Associations were analyzed using a modified Poisson regression adjusted for covariates, and in interaction models. RESULTS: Both postpartum and recurrent depression were associated with higher risk of current wheeze (relative risk [RR]: 1.87, 95% confidence interval [CI]: 1.21, 2.90; RR: 2.41, 95% CI: 1.53, 3.79) and asthma at 48 months (RR: 2.42, 95% CI: 1.01, 5.84; RR: 2.45, 95% CI: 1.02, 5.84). In interaction analyses, associations were stronger in females. Recurrent depression was associated with a higher risk of current wheeze at 48 months in females (RR: 4.34, 95% CI: 2.02, 9.32) when compared to males (RR: 1.89, 95% CI: 1.05, 3.39). CONCLUSIONS: Postpartum and recurrent depression were associated with a higher risk of wheeze and asthma in children. Understanding the temporal- and sex-specific effects of maternal depression may better inform prevention strategies.

Association between prenatal particulate air pollution exposure and telomere length in cord blood: Effect modification by fetal sex.

INTRODUCTION: In utero particulate matter exposure produces oxidative stress that impacts cellular processes that include telomere biology. Newborn telomere length is likely critical to an individual's telomere biology; reduction in this initial telomere setting may signal increased susceptibility to adverse outcomes later in life. We examined associations between prenatal particulate matter with diameter ≤2.5 µm (PM2.5) and relative leukocyte telomere length (LTL) measured in cord blood using a data-driven approach to characterize sensitive windows of prenatal PM2.5 effects and explore sex differences. METHODS: Women who were residents of Mexico City and affiliated with the Mexican Social Security System were recruited during pregnancy (n = 423 for analyses). Mothers' prenatal exposure to PM2.5 was estimated based on residence during pregnancy using a validated satellite-based spatio-temporally resolved prediction model. Leukocyte DNA was extracted from cord blood obtained at delivery. Duplex quantitative polymerase chain reaction was used to compare the relative amplification of the telomere repeat copy number to single gene (albumin) copy number. A distributed lag model incorporating weekly averages for PM2.5 over gestation was used in order to explore sensitive windows. Sex-specific associations were examined using Bayesian distributed lag interaction models. RESULTS: In models that included child's sex, mother's age at delivery, prenatal environmental tobacco smoke exposure, pre-pregnancy BMI, gestational age, birth season and assay batch, we found significant associations between higher PM2.5 exposure during early pregnancy (4-9 weeks) and shorter LTL in cord blood. We also identified two more windows at 14-19 and 34-36 weeks in which increased PM2.5 exposure was associated with longer LTL. In stratified analyses, the mean and cumulative associations between PM2.5 and shortened LTL were stronger in girls when compared to boys. CONCLUSIONS: Increased PM2.5 during specific prenatal windows was associated with shorter LTL and longer LTL. PM2.5 was more strongly associated with shortened LTL in girls when compared to boys. Understanding sex and temporal differences in response to air pollution may provide unique insight into mechanisms.

Association between particulate air pollution exposure during pregnancy and postpartum maternal psychological functioning.

METHODS: We studied associations between prenatal exposure to particulate matter with diameter ≤ 2.5 µm (PM2.5) and postpartum psychological functioning in a lower income, ethnically mixed sample of urban US women enrolled in a pregnancy cohort study. Analyses included 557 mothers who delivered at ≥37 weeks gestation. Daily estimates of residential PM2.5 over gestation were derived using a satellite-based spatio-temporally resolved model. Outcomes included the Edinburgh Postnatal Depression Scale (EPDS) score from 6 or 12 months postpartum and subscale scores for anhedonia, depressive and anxiety symptoms. Associations were also examined within racial/ethnic groups. Distributed lag models (DLMs) were implemented to identify windows of vulnerability during pregnancy. RESULTS: Most mothers had less than a high school education (64%) and were primarily Hispanic (55%) and Black (29%). In the overall sample, a DLM adjusted for age, race, education, prenatal smoking, and season of delivery, we found significant associations between higher PM2.5 exposure in the second trimester and increased anhedonia subscale scores postpartum. In race stratified analyses, mid-pregnancy PM2.5 exposure was significantly associated with increased total EPDS scores as well as higher anhedonia and depressive symptom subscale scores among Black women. CONCLUSIONS: Increased PM2.5 exposure in mid-pregnancy was associated with increased depressive and anhedonia symptoms, particularly in Black women.

Identifying sensitive windows for prenatal particulate air pollution exposure and mitochondrial DNA content in cord blood.

INTRODUCTION: Changes in mitochondrial DNA (mtDNA) can serve as a marker of cumulative oxidative stress (OS) due to the mitochondria's unique genome and relative lack of repair systems. In utero particulate matter ≤2.5µm (PM2.5) exposure can enhance oxidative stress. Our objective was to identify sensitive windows to predict mtDNA damage experienced in the prenatal period due to PM2.5 exposure using mtDNA content measured in cord blood. MATERIAL AND METHODS: Women affiliated with the Mexican social security system were recruited during pregnancy in the Programming Research in Obesity, Growth, Environment and Social Stressors (PROGRESS) study. Mothers with cord blood collected at delivery and complete covariate data were included (n=456). Mothers' prenatal daily exposure to PM2.5 was estimated using a satellite-based spatio-temporally resolved prediction model and place of residence during pregnancy. DNA was extracted from umbilical cord leukocytes. Quantitative real-time polymerase chain reaction (qPCR) was used to determine mtDNA content. A distributive lag regression model (DLM) incorporating weekly averages of daily PM2.5 predictions was constructed to plot the association between exposure and OS over the length of pregnancy. RESULTS: In models that included child's sex, mother's age at delivery, prenatal environmental tobacco smoke exposure, birth year, maternal education, and assay batch, we found significant associations between higher PM2.5 exposure during late pregnancy (35-40weeks) and lower mtDNA content in cord blood. CONCLUSIONS: Increased PM2.5 during a specific prenatal window in the third trimester was associated with decreased mtDNA content suggesting heightened sensitivity to PM-induced OS during this life stage.