Pregnancy accelerates aging – but only temporarily

But this is only temporary; after the birth, these processes are reversed again. Scientists led by Kieran O’Donnel from the Yale Child Study Center in the USA have now discovered this and published the results of their work in the specialist journal “Cell Metabolism”.

The main results, according to a release from the Yale School of Medicine (New Haven/US state of Connecticut): “From the early to the late period of pregnancy – i.e. for around 20 weeks – the biological age, which is determined by epigenetic processes, increases around two years. This suggests that pregnancy really speeds up the aging process.”

Decrease in biological age

However, when O’Donnel and his team later repeated the tests with young mothers, they were amazed. The scientist explained: “Three months after the birth, we saw an astonishing decrease in biological age – for some of the women by up to eight years.”

The researchers examined the so-called DNA methylation of 199 women who gave blood samples in early, middle and late pregnancy as part of another study. A fourth blood sample was taken from 68 women three months after the birth, the German Medical Journal also wrote.

The addition of methyl groups to the genetic material influences the readability of the DNA and thus the biological age that can be read from the patterns. According to the experts, stress is the decisive factor. Such epigenetic changes can also be caused by serious injuries, surgical procedures or diseases such as diabetes or high blood pressure.

The research results (DOI: 10.1016/j.cmet.2024.02.016) show strong and very rapid changes. With only 18 weeks between the first examination and the birth of the participants’ child, the epigenetic changes occurred extremely quickly: depending on the assessment method used (biological clocks), the biological age increased by 1.19 to 2.52 years. Obesity at the start of pregnancy caused it to increase by an additional 0.66 to 1.42 years.