A prospective study has found that pregnancy can accelerate epigenetic ageing in women by up to 5.3 years.
The study, published in Obstetrics and Gynaecology and conducted by Dr Danielle Panelli et al, recruited 75 nulliparous women aged 18 to 50 who sought obstetric (10-14 weeks’ pregnant) or gynaecologic (non-pregnant) care between 2020 and 2021. Of the 75 women enrolled, 45 (60%) were pregnant. By the end of the study, 61 participants (81.3%) completed all follow-up assessments.
During the study, blood samples were collected at enrolment and again either one day postpartum for pregnant women or seven months later for nonpregnant participants. Researchers used 11 established epigenetic “clocks” to measure biological age based on molecular markers. These tools allowed the team to track within-person changes in epigenetic age over time, adjusting for confounding factors such as chronological age and body mass index (BMI).
The results revealed significant epigenetic age acceleration among pregnant women compared to their nonpregnant counterparts. Specifically, six of the clocks – including Hannum, PhenoAge, GrimAge, and DunedinPACE – showed notable increases. For example, over approximately 200 days, pregnant women’s biological age increased by 1.58 years according to the Hannum clock and by as much as 5.28 years per the PhenoAge clock.
The study also linked accelerated biological ageing in early pregnancy to a higher risk of immune-related pregnancy complications, such as hypertensive disorders, gestational diabetes, preterm birth and small-for-gestational age babies. Each additional year of epigenetic age measured by the GrimAge2 clock increased the odds of such complications by 36%, even after adjusting for age and BMI. Chronological age showed no such association.
Dr Panelli et al, commented, “Our results suggest that biological ageing may serve as a useful metric to objectively measure how pregnancy can serve as a window to future health since we know that people who develop gestational diabetes and hypertensive disorders can be at increased risk for these health conditions later in life”