If you’re stressed during pregnancy, you’re more likely to have a girl, study suggests

Physical and psychological stress can cause birth complications

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Stress during pregnancy can certainly cause health issues. But did you know it might also affect the sex of the baby?

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Researchers from Columbia University Irving Medical Center recently conducted a study to explore the effects of maternal prenatal stress.

To do so, they examined 187 women ages 18-25. The participants completed questionnaires, diaries and daily physical reports that assessed their psychological and physical well-being.

About 17% of the subjects were psychologically stressed or struggling with depression and anxiety, while 16% of them were physically stressed because of hypertension and high caloric intake. Nearly 67% of them were healthy.

After analyzing the data, the team said moms-to-be who were physically or psychologically stressed were less likely to have a boy.

"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," study leader Catherine Monk said in a statement. "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."

The team also found physically stressed moms were more likely to give birth prematurely, compared to non-stressed mothers.

Additionally, physically stressed women gave birth to more fetuses with a reduced heart rate, and psychologically stressed mothers had more birth complications.

Although they did not examine why a mother’s stress levels might affect her fetus, they said “high levels of stress can raise levels of stress hormones like cortisol in the uterus, which in turn can affect the fetus.”

The scientists now hope to continue their studies to emphasize the importance of social support for expecting mothers.

“Screening for depression and anxiety are gradually becoming a routine part of prenatal practice,” Monk said. “But while our study was small, the results suggest enhancing social support is potentially an effective target for clinical intervention.”

Read more about the findings, which were published in the journal PNAS, the Proceedings of the National Academy of Sciences.

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