Pregnancy turns back the clock

Malaika Matin
Honours Life Sciences, Class of 2023, McMaster University
matins1@mcmaster.ca

Pregnancy is a complex enough biological process as it is due to the vast number of hormonal fluctuations as the body provides nourishment to the fetus and prepares for labor.¹ Changes in hormone levels go hand in hand with changes in the anatomy of the brain, such as a reduction in gray matter volume. A study done by Luders and colleagues studied potential age reversal effects in the brain following pregnancy. A decline in gray matter and brain volume is a side effect of aging, which is why researchers decided to take matters into their own hands to study the pregnancy-induced effects on brain anatomy. To study these effects, the researchers obtained cerebral image data from 14 young and healthy mothers during early postpartum (within 2 days of giving birth) and late postpartum (4-6 weeks following childbirth). The age of the brain was estimated using a well-validated machine learning method on the basis of pattern recognition; the algorithm used for identifying anatomical relationships of age throughout the brain measures a BrainAGE index score for each subject by measuring alterations in gray matter volume. The BrainAGE indices were compared for the early postpartum and late postpartum groups. The researchers discovered that brains during late postpartum are measured to be five years younger according to the BrainAGE index score than brains from an earlier stage of postpartum due to the reduction in gray matter. This study also has several limitations, including the small sample size, as well as the lack of hormonal and imaging data obtained prior to pregnancy. It would also be useful for future studies in the field of pregnancy and aging to account for data in even later stages of postpartum following the 4-6 weeks used in this study. Lastly, future studies should also take into account that the cognitive and behavioral demands of motherhood are likely to pose as a confounding variable for such studies as they are likely to remodel the brain. Overall, this study suggests potential restoration and rejuvenation effects following birth and sheds light on the role that pregnancy plays on age reversal. As a result of these findings on age reversal following pregnancy, the road to understanding the impact of hormonal levels on aging is sooner than expected

1. Luders, E., Gingnell, M., Poromaa, I., Engman, J., Kurth, F. and Gaser, C. 2018. Potential Brain Age Reversal after Pregnancy: Younger Brains at 4–6 Weeks Postpartum. Neuroscience, 386.