Assessing the effect of childbearing on blood DNA methylation through comparison of parous and nulliparous females

• Published in: Epigenetics communications 2024-12, Vol.4 (1), p.2-15, Article 2
• Main Authors: Chen, Su, Johs, Miranda, Karmaus, Wilfried, Holloway, John W., Kheirkhah Rahimabad, Parnian, Goodrich, Jaclyn M., Peterson, Karen E., Dolinoy, Dana C., Arshad, S. Hasan, Ewart, Susan
• Format: Article
• Language: English
• Subjects: Age; Childbearing; CpG; DNA methylation; Gene expression; Nulliparous; Ontology; Parous; Pilot projects; Pregnancy; Smoking; Womens health
• ISSN: 2730-7034; 2730-7034
• DOI: 10.1186/s43682-024-00025-9

BackgroundPregnancy and childbirth have been connected to modified risk of a wide variety of conditions in later life, including neurodegenerative disorders and cancers. The presence, extent, and direction of the effect that childbearing status has on decreasing or increasing the risk of these conditions differs depending on the disease. The mechanisms by which pregnancy and childbirth modify the risk of diseases are still unknown. DNA methylation (DNAm) alterations that occur during pregnancy and persist after childbirth may help us understand this phenomenon.ResultsBlood DNAm was available from 89 women (28 parous; 61 nulliparous) at ages 18 and 26 years in the Isle of Wight birth cohort; no significant differences in the population characteristics were present between the analyzed population and the full cohort. We performed an epigenome-wide association study on 389,355 CpGs and identified 184 CpGs to be significantly differentially methylated between parous and nulliparous women after adjusting for confounders and multiple testing. Of these CpGs, 105 had regression coefficients in the same direction in an independent Mexico City based ELEMENT cohort, of which 13 were significant (replication P