Cord blood DNA methylation signatures associated with preeclampsia are enriched for cardiovascular pathways: insights from the VDAART trial.

BACKGROUND: Preeclampsia has been associated with maternal epigenetic changes, in particular DNA methylation changes in the placenta. It has been suggested that preeclampsia could also cause DNA methylation changes in the neonate. We examined DNA methylation in relation to gene expression in the cord blood of offspring born to mothers with preeclampsia. METHODS: This study included 128 mother-child pairs who participated in the Vitamin D Antenatal Asthma Reduction Trial (VDAART), where assessment of preeclampsia served as secondary outcome. We performed an epigenome-wide association study of preeclampsia and cord blood DNA methylation (Illumina 450 K chip). We then examined gene expression of the same subjects for validation and replicated the gene signatures in independent DNA methylation datasets. Lastly, we applied functional enrichment and network analyses to identify biological pathways that could potentially be involved in preeclampsia. FINDINGS: In the cord blood samples (n = 128), 263 CpGs were differentially methylated (FDR <0.10) in preeclampsia (n = 16), of which 217 were annotated. Top pathways in the functional enrichment analysis included apelin signaling pathway and other endothelial and cardiovascular pathways. Of the 217 genes, 13 showed differential expression (p's < 0.001) in preeclampsia and 11 had been previously related to preeclampsia (p's < 0.0001). These genes were linked to apelin, cGMP and Notch signaling pathways, all having a role in angiogenic process and cardiovascular function. INTERPRETATION: Preeclampsia is related to differential cord blood DNA methylation signatures of cardiovascular pathways, including the apelin signaling pathway. The association of these cord blood DNA methylation signatures with offspring's long-term morbidities due to preeclampsia should be further investigated. FUNDING: VDAART is funded by National Heart, Lung, and Blood Institute grants of R01HL091528 and UH3OD023268. HMK is supported by Jane and Aatos Erkko Foundation, Paulo Foundation, and the Pediatric Research Foundation. HM is supported by K01 award from NHLBI (1K01HL146977-01A1). PK is supported by K99HL159234 from NIH/NHLBI.

Early life gut microbiome in children following spontaneous preterm birth and maternal preeclampsia.

The early life microbiome plays an important role in developmental and long-term health outcomes. However, it is unknown whether adverse pregnancy complications affect the offspring's gut microbiome postnatally and in early years. In a longitudinal cohort with a five-year follow-up of mother-child pairs affected by preeclampsia (PE) or spontaneous preterm birth (sPTB), we evaluated offspring gut alpha and beta diversity as well as taxa abundances considering factors like breastfeeding and mode of delivery. Our study highlights a trend where microbiome diversity exhibits comparable development across adverse and normal pregnancies. However, specific taxa at genus level emerge with distinctive abundances, showing enrichment and/or depletion over time in relation to PE or sPTB. These findings underscore the potential for certain adverse pregnancy complications to induce alterations in the offspring's microbiome over the course of early life. The implications of these findings on the immediate and long-term health of offspring should be investigated in future studies.

The relationship of fetal sex and maternal race and ethnicity with early and late pregnancy C-reactive protein and interleukin-8.

PROBLEM: Promotion of a healthy pregnancy is dependent on a coordinated immune response that minimizes inflammation at the maternal-fetal interface. Few studies investigated the effect of fetal sex on proinflammatory biomarkers during pregnancy and whether maternal race could impact this association. We aimed to examine whether fetal sex could, independently of maternal race/ethnicity and the condition of pregnancy (normal vs. complicated), impact inflammatory markers (C-reactive protein [CRP] and interleukin-8 [IL-8] levels) in early and late pregnancy. METHODS OF STUDY: This study was a cohort analysis using prospectively collected data from pregnant women who participated in the Vitamin Antenatal Asthma Reduction Trial (VDAART, N = 816). Maternal serum CRP and IL-8 levels were measured in early and late pregnancy (10-18 and 32-38 weeks of gestation, respectively). Five hundred and twenty-eight out of 816 pregnant women who participated in the trial had available CRP and IL-8 measurements at both study time points. We examined the association of fetal sex with early and late CRP and IL-8 levels and their paired sample difference. We further investigated whether maternal race/ethnicity, pregnancy complications (i.e., preeclampsia and gestational diabetes), and early pregnancy body mass index (BMI) could affect the association between these two biomarkers and fetal sex adjusting for potential confounders. For this purpose, we used generalized linear and logistic regression models on log-normalized early and late CRP and IL-8 levels as well as their split at median to form high and low groups. RESULTS: Women pregnant with male fetuses (266/528 = 56.5%) had higher CRP levels in early to mid-pregnancy (ß = .18: 95% confidence interval [CI]: CI = 0.03-0.32; p = .02). Twenty-seven percent (143/528) of the study subjects were Hispanic. Hispanic African American [AA] women and women of races other than White and AA had higher levels of CRP at early to mid-pregnancy compared with White women (ß = .57; 95% CI: 0.17-0.97; p < .01 and ß = .27; 95% CI: 0.05-0.48; p = .02, respectively). IL-8 levels were not associated with fetal sex in early and late pregnancy (p's > .05). Other factors such as gestational diabetes and early pregnancy BMI were associated with higher CRP levels and higher CRP and IL-8 levels, respectively. Dichotomizing log-normalized cytokine levels at the median in a sensitivity analysis, women with male fetuses had lower odds of high (above-median) IL-8 levels at early pregnancy. Also, women with races other than AA and White carrying male fetuses had higher odds of having high (above-median) late-pregnancy CRP and early-pregnancy IL-8 levels (adjusted odds ratio [aOR] = 3.80, 95% CI: 0.24-1.23; p = .02 and aOR = 3.57; 95% CI: 0.23-1.03; p = .02, respectively). Of the pregnancy complications, women with gestational diabetes mellitus had a higher paired difference of early and late pregnancy CRP levels (ß = .38; 95% CI: 0.09-0.68; p = .01), but no difference in IL-8 levels (p's > .05). No associations between the inflammatory markers and preeclampsia were found. CONCLUSION: Fetal sex is associated with CRP in early pregnancy and an association with IL-8 in early pregnancy is implied. Our study further indicates that maternal race/ethnicity could be a contributing factor in the relationship between fetal sex and inflammatory responses during pregnancy. However, the specificity and level of the contribution might vary by type of cytokine, pregnancy stage, and other confounding factors such as BMI that may impact these associations.

Early-Life Weight Status and Risk of Childhood Asthma or Recurrent Wheeze in Preterm and Term Offspring.

BACKGROUND: Excessive weight is associated with the development of childhood asthma. However, trends among preterm and term offspring may differ. OBJECTIVE: To assess whether the association of longitudinal weight for age (WFA) and odds of asthma/recurrent wheeze in early life differs between children born preterm and those born at term. METHODS: This study used prospectively collected data from the Vitamin D Antenatal Asthma Reduction Trial. Children (n = 804) were followed-up and anthropometric measurements, including WFA, were taken at birth and annually until the age of 6 years. The primary outcome was asthma/recurrent wheeze by age 3 and 6 years. RESULTS: Among the offspring, 71 (8.8%) were premature. In all the children, the odds of asthma/recurrent wheeze increased by 15% (adjusted odds ratio [aOR], 1.15; 95% CI, 1.10-1.20; P < .001) by age 3 years and 9% (aOR, 1.09; 95% CI, 1.07-1.11; P < .001) by age 6 years for each unit increase in WFA z score. Odds were different between term and preterm offspring (Pinteraction < .001). In term offspring, the odds of having asthma/recurrent wheeze by age 3 and 6 years increased by 22% and 15%, respectively (aOR, 1.22, 95% CI, 1.16-1.27, P < .001, and aOR, 1.15, 95% CI, 1.11-1.18, P < .001). In preterm offspring, by age 3 years, odds of asthma/recurrent wheeze decreased by 10% for each unit increase in WFA z score (aOR, 0.90; 95% CI, 0.81-0.99; P = .030) and decreased by 27% by age 6 years (aOR, .73; 95% CI, 0.61-0.86; P < .001). CONCLUSIONS: During early life, increasing standardized WFA is associated with higher odds of asthma/recurrent wheeze in term children. In contrast, in preterm children, a higher standardized WFA during catch-up growth may decrease the odds of asthma/recurrent wheeze associated with prematurity.

The Impact of Baseline 25-Hydroxyvitamin D Level and Gestational Age on Prenatal Vitamin D Supplementation to Prevent Offspring Asthma or Recurrent Wheezing.

BACKGROUND: Prenatal vitamin D deficiency is associated with asthma or recurrent wheezing in offspring. However, evidence from randomized trials on the efficacy of vitamin D supplementation is inconclusive. OBJECTIVES: We aimed to examine the differential efficacy of prenatal vitamin D supplementation based on the maternal baseline vitamin D status and the starting time of supplementation to prevent early life asthma or recurrent wheezing. METHODS: We conducted a secondary analysis of the Vitamin D Antenatal Asthma Reduction Trial (VDAART), a randomized double-blind trial of prenatal vitamin D supplementation initiated at 10-18 weeks (wks) of gestation (4400 IU of intervention/day compared with 400 IU of placebo/day) to prevent offspring asthma or recurrent wheezing by the age of 6 years. We assessed the effect of modification of supplementation by maternal baseline vitamin D status at enrollment and the timing of initiation of supplementation. RESULTS: An inverse relationship was observed between maternal 25-hydroxyvitamin D (25(OH)D) levels at trial entry and 25(OH)D levels during late pregnancy (32-38 wks of gestation) in both supplementation arms (P < 0.001). Overall, supplementation efficacy was not dependent on the maternal baseline 25(OH)D status. However, a trend toward the reduction of asthma or recurrent wheezing was observed across the baseline groups in the intervention arm (P = 0.01), with the greatest reduction observed in the most severely vitamin D-deficient women (25(OH)D < 12 ng/mL; adjusted odds ratio [aOR] = 0.48; confidence interval [CI]: 0.17, 1.34). Gestational age at trial enrollment modified supplementation efficacy, showing a greater reduction of offspring asthma or recurrent wheezing with earlier intervention during pregnancy (aOR = 0.85; CI = 0.76, 0.95), particularly in women who were 9-12 wk pregnant (aOR = 0.45; CI = 0.24, 0.82). CONCLUSIONS: Pregnant women with severe vitamin D deficiency show the greatest 25(OH)D improvement because of supplementation. In these women, a vitamin D dose of 4400 IU might have a preventive role in the development of early life offspring asthma or recurrent wheezing. Gestational age is suggested to modify the efficacy of prenatal vitamin D supplementation, showing the highest beneficial effect if supplementation is started during the first trimester of pregnancy. This study is an ancillary analysis from the VDAART, which is registered in ClinicalTrials.gov as NCT00902621.