Exposure to the synthetic environmental chemical phthalate was linked with lower progesterone levels during pregnancy and an increased likelihood of postpartum depression, according to a study published online ahead of print in The Journal of Clinical Endocrinology & Metabolism.
“This research is important because phthalates are so prevalent in the environment that they are detectable in nearly all pregnant women in the United States,” said study author Melanie Jacobson, PhD, MPH, of NYU Langone Medical Center in New York, New York. “If these chemicals can affect prenatal hormone levels and subsequently postpartum depression, reducing exposure to these types of chemicals could be a plausible avenue for preventing postpartum depression.”
The study included 139 pregnant women. Researchers measured levels of bisphenols and phthalates—chemicals found in plastics and personal care products that are known to affect sex hormones—in urine samples from the women in early and mid-pregnancy. At 4 months postpartum, the women were assessed for postpartum depression using the Edinburgh Postnatal Depression Scale.
Women with higher levels of phthalates in their urine were at greater likelihood of developing postpartum depression, the study found. Women with higher levels of phthalates also had lower levels of the hormone progesterone. Researchers explained that progesterone plays an important role in menstrual cycle, maintaining early pregnancy stages, and in modulating mood.
“These results need to be interpreted with caution,” Dr. Jacobson added, “as this is the first study to examine these chemicals in relation to postpartum depression and our sample size was small.”
Jacobson MH, Stein CR, Liu M, et al. Prenatal exposure to bisphenols and phthalates and postpartum depression: the role of neurosteroid hormone disruption. The Journal of Clinical Endocrinology & Metabolism. 2021 April 1;[Epub ahead of print].