Pregnant people who are depressed in early and mid-pregnancy appear to have placentas that age more rapidly than placentas of pregnant people who aren’t depressed, suggests a study by researchers at the National Institutes of Health. The authors theorized that premature placental aging could account for higher rates of low birth weight, preterm birth, blood pressure disorders, diabetes, and other complications linked to depression in pregnancy. The findings underscore the need to diagnose and treat depression during pregnancy.
The study was conducted by Fasil Tekola-Ayele, Ph.D., of NIH’s Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and colleagues. It appears in the American Journal of Obstetrics & Gynecology Maternal-Fetal Medicine.
Background
Previous studies have linked depression during pregnancy to a higher risk of miscarriage, preterm delivery, preeclampsia (a hypertensive disorder of pregnancy), and children’s low cognitive development scores. Other studies suggest that hormones associated with stress and depression could affect the placenta.
For the current study, placentas were donated by pregnant people after giving birth. Researchers tested the placentas for epigenetic modifications—patterns occurring when compounds known as methyl groups bind to DNA. Like a light switch, the process, known as DNA methylation, can turn genes on or off, depending on the binding patterns. The authors estimated aging in the placental samples by analyzing their DNA methylation patterns.
The 301 participants who provided placenta samples were part of a larger study that used ultrasound to observe patterns of fetal growth throughout pregnancy. Study participants were screened for depression during each trimester with a questionnaire that ranked their symptoms.
Results
Of the participants, 31 (10.3%) had depressive symptoms in the first trimester, 48 (16%) in the second trimester, and 49 (16.4%) in the third trimester. Of these, 21 (7.2%) women had first and second trimester depressive symptoms and 19 (7%) had second and third trimester depressive symptoms.
Compared to participants without depressive symptoms, participants with depressive symptoms in the second trimester had placentas that aged an average of .41 weeks faster than those without depressive symptoms. Placentas of male fetuses of participants with second trimester depressive symptoms aged .53 weeks faster than those without depressive symptoms. However, placental aging in participants with female fetuses did not differ significantly between those who had second trimester depressive symptoms and those who did not.
Participants with first and second trimester depressive symptoms had placentas that aged an average 0.72 weeks faster than those without depressive symptoms.
The authors did not find an association between placental aging and depression in the third trimester. They noted that of these participants, roughly 61% were not depressed in the second trimester and theorized that the comparatively limited exposure to depression late in pregnancy was not enough to influence placental aging.
Significance
Currently, it is recommended that pregnant people be screened for depression from late in the second trimester to early in the third trimester (from 24-28 weeks). If the current findings are confirmed, it may be more helpful to screen for depression earlier in pregnancy, from the first to the second trimester.
In addition, given that depression-associated aging was greater in pregnancies with male fetuses, researchers may want to distinguish between pregnancies with male and female fetuses in future studies.
Reference
Saeed, H, et al. Placental Accelerated Aging in Antenatal Depression. American Journal of Obstetrics & Gynecology Maternal-Fetal Medicine. 2023. https://doi.org/10.1016/j.ajogmf.2023.101237 
.
BACK TO TOP