Maternal dyslipidemia during early pregnancy and epigenetic ageing of the placenta

Disruption of physiological ageing of the placenta is associated with obstetric complications. Altered lipid metabolism is a known trigger of tissue ageing, but the effect of maternal dyslipidemia on placental ageing is not clearly understood. We examined the relationship between maternal dyslipidemia and placental age acceleration (PAA), an epigenetic ageing measure derived from the difference between DNA methylation age and chronological gestational age. We also assessed whether the association varies by maternal pre-pregnancy obesity status and fetal sex. Placental data were obtained as part of the NICHD Fetal Growth Studies that involved participants from four race/ethnic groups. Placental DNA methylation age was estimated using 62 CpGs that have previously been found to have high placental age prediction accuracy. We used multivariable linear regression to test associations between maternal dyslipidemia during early gestation (i.e., high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), total cholesterol (TChol), and triglycerides) and PAA adjusting for fetal sex and socio-demographic factors. Among normal-weight women, low HDLc, compared to high HDLc, was associated with 0.82 (95% CI: 0.00, 1.64) weeks higher PAA. Among women with female neonates, low HDLc, compared to high HDLc, was associated with 1.20 (95% CI: 0.17, 2.24) weeks higher PAA. High TChol was associated with 1.28 (95% CI: 0.12, 2.45) weeks higher PAA among Whites. In all, the study found that maternal dyslipidemia due to low HDLc was associated with accelerated epigenetic ageing of the placenta among mothers with normal pre-pregnancy weight and a female fetus.