Mode of birth and DNA methylation at birth, in childhood, and in adolescence: Uncovering the relationship using ALSPAC data.

Mode of birth has been linked to offspring health. Changes in DNA methylation (DNAm) may represent a potential mechanism; however, findings are heterogeneous and limited to early infancy. This preregistered study examined whether mode of birth (vaginal birth compared with elective or emergency cesarean section) affects DNAm at birth, in childhood, and adolescence and whether these effects are modified by the postnatal care environment, specifically by breastfeeding and mother-infant bonding. Using data from 876 mother-infant dyads from the U.K. Avon Longitudinal Study of Parents and Children, we examined differentially methylated cytosine-phosphate-guanine dinucleotides and regions associated with mode of birth. DNAm was quantified using Illumina Infinium Human Methylation 450 K BeadChip in cord blood (at birth) and in peripheral blood (at 7 and 15-17 years). Analyses controlled for maternal age, education, smoking during pregnancy, child sex, gestational week at birth, and batch effects. We also examined interactions of mode of birth with breastfeeding practices and mother-infant bonding. In cord blood, two cytosine-phosphate-guanine dinucleotides (cg05230316; cg13230077) were linked to mode of birth (pFDR < .050). DNAm in childhood or adolescence was not statistically associated with mode of birth (pFDR > .050), and breastfeeding and mother-infant bonding were not moderators (p > .050). Overall, findings suggest mode of birth may have a small effect on cord blood DNAm, but these effects may not persist into later developmental stages. Other postnatal influences should be considered, and further investigation is needed to address study limitations. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Birth expectations, birth experiences and childbirth-related post-traumatic stress symptoms in mothers and birth companions: Dyadic investigation using response surface analysis.

OBJECTIVES: During the perinatal period, women and their birth companions form expectations about childbirth. We aimed to examine whether a mismatch between birth expectations and experiences predict childbirth-related post-traumatic stress symptoms (CB-PTSS) for mothers and birth companions. We also explored the influence of the mismatch between mothers' and birth companions' expectations/experiences on CB-PTSS. DESIGN: Dyadic longitudinal data from the Self-Hypnosis IntraPartum Trial. METHODS: Participants (n = 469 mothers; n = 358 birth companions) completed questionnaires at 27 and 36 weeks of gestation and 2 and 6 weeks post-partum. We used the measures of birth expectations (36 weeks gestation), birth experiences (2 weeks post-partum) and CB-PTSS (6 weeks post-partum). RESULTS: Correlations revealed that birth expectations were associated with experiences for both mothers and birth companions but were not consistently associated with CB-PTSS. Birth experiences related to CB-PTSS for both mothers and birth companions. The response surface analysis results showed no support for the effect of a mismatch between expectations and experiences on CB-PTSS in mothers or birth companions. Similarly, a mismatch between mothers' and birth companions' expectations or experiences was unrelated to CB-PTSS. CONCLUSIONS: Following previous literature, birth expectations were associated with experiences, and experiences were associated with CB-PTSS. By testing the effect of the match between birth experiences and expectations using an advanced statistical method, we found that experiences play a more substantial role than the match between experiences and expectations in CB-PTSS. The impact of birth experiences on CB-PTSS highlights the importance of respectful and supportive maternity care.