Women with Prenatal Stress Are Less Likely To Have a Boy, Finds Study

    “Screening for depression and anxiety are gradually becoming a routine part of prenatal practice.”


    Multiple studies have found that maternal or prenatal stress could affect the growth and development of the fetus. Now, a new study has identified the types of “physical and psychological stress” during pregnancy, which could affect the child’s sex.

    Researchers at Columbia University Vagelos College of Physicians and Surgeons and NewYork-Presbyterian found that women who experience physical and psychological stress during pregnancy are less likely to have a boy.

    The study was published in the journal called Proceedings of the National Academy of Sciences (PNAS).

    Lead study author and professor of medical psychology Dr. Catherine Monk said, “The womb is an influential first home, as important as the one a child is raised in, if not more so.”

    Dr. Monk and her team looked at 27 signs of physical, psychosocial, and lifestyle stress of 187 pregnant women. The data was collected through questionnaires, diaries, and physical assessments.

    • About 32 women were psychologically stressed, with a high degree of clinical depression, anxiety, and stress.
    • About 30 were physically stressed, with high blood pressure and higher caloric intake
    • Remaining 125 were healthy

    The researchers found that pregnant women who experienced physical and psychological stress were less likely to have a boy. In the physically (30) and psychologically (32) stressed groups, the sex ratio favored girls.

    Dr. Monk said, “Other researchers have seen this pattern after social upheavals, such as the 9/11 terrorist attacks in New York City, after which the relative number of male births decreased.”

    “This stress in women is likely of long-standing nature; studies have shown that males are more vulnerable to adverse prenatal environments, suggesting that highly stressed women may be less likely to give birth to a male due to the loss of prior male pregnancies, often without even knowing they were pregnant,” added the lead study author.

    The researchers also found that pregnant women with psychological stress had more birth complications and pregnant women with physical stress were more likely to give birth prematurely.  

    “Screening for depression and anxiety are gradually becoming a routine part of prenatal practice,” said Dr. Monk. “But while our study was small, the results suggest enhancing social support is potentially an effective target for clinical intervention.” According to the researchers, more than 30 percent of pregnant women report psychological stress caused by job or related to anxiety and depression. And such stress has been linked to an increased risk of premature birth.