*For medical professionals only
It's a bit bizarre to talk about this paper today.
We all know that pregnancy, both psychologically and physically, is a great burden for women. Singularity Cake's friend was seen to be haggard with the naked eye after giving birth, and it was really distressing.
Therefore, the first half of the conclusion given by this paper, "pregnancy makes people old", is really not surprising.
But what's interesting is that when the child is born, can he still be young again?
Recently, the journal Cell Metabolism published an article from a research team at Yale Medical School. Scientists analyzed blood samples from 119 pregnant women at different points in pregnancy/childbirth, and judged their biological age by methylation levels, and found that pregnancy would bring a significant increase in biological age, and from the third trimester to 3 months after delivery, the biological age would be greatly reduced, and the reduction rate even reached 2-3 times the increase caused by pregnancy.
Colleague: Having a baby and detoxifying it, right?
Diagram of the title of the dissertation
Biological age refers to the actual age inferred from the physiological state of the body, which represents the true state of the body's tissue structure and function. It is common to use epigenetic clocks to infer biological age, and three computational models were used in this study: PCHorvath1, PCPhenoAge, and PCGrimAge.
The study participants were drawn from a prospective, longitudinal human pregnancy cohort and included DNA methylation data from blood samples from 119 pregnant women in the first, middle, and third trimesters, and 68 of them at three months after delivery.
Maternal age, parity, race and ethnicity, educational attainment, household income, and other technical factors were adjusted for in the model analysis. In addition, because body mass index (BMI) may further increase the physiological burden of pregnancy, the researchers specifically conducted a stratified analysis for BMI.
As we can see from the figure below, there was a significant increase in maternal biological age from the first to the second trimester, with the three models used increasing by 2.39 years, 1.19 years, and 2.52 years, respectively.
Pregnancy is really old.
There is a significant increase in biological age from the first to the second trimester
Curiously, however, the increased biological age decreases rapidly from the third trimester to the postpartum period, and even reverses to a lower level than in the first trimester.
It's hard not to think that something is out of the body with the child
In addition, we can also observe that the maternal age "rejuvenation" effect of BMI=30 is weaker than that of pregnant women with BMI=23.
In the analysis, the researchers also found another variable that affects biological age change, breastfeeding. Pregnant women who exclusively breastfed their children had more postpartum biological age recovery than those who used formula.
Breastfeeding is also a factor influencing biological age change
In response to the results of the study, some scholars have expressed different opinions. Although we use DNA methylation as a criterion for biological age change, it is not known whether methylation can still represent aging when it comes to pregnancy and childbirth. After all, in order to support fetal growth, the body must be involved in changes in gene expression, and methylation is likely to represent this process.
Resources:
[1]https://www.sciencedirect.com/science/article/abs/pii/S1550413124000792
[2]https://www.nature.com/articles/d41586-024-00843-w
The author of this article丨 Dai Siyu