A Stressful Pregnancy Reduces The Chance Of Having A Boy

by Cassandra Stone
Originally Published: 
Jill Lehmann Photography/Getty

Enduring physical or mental stress during pregnancy means you’re less likely to have a boy

Pregnancies that include physical or mental stress may have a huge impact on the sex of the baby, according to a new study. Pregnant people who undergo physical or mental stress during their pregnancies are less likely to have a boy. They may also have a higher risk of preterm birth.

“The womb is an influential first home,” says the lead author of the study Catherine Monk, director of women’s mental health in OB/GYN at NewYork-Presbyterian/Columbia University Irving Medical Center. “We do know that males are more vulnerable in utero, and presumably the stress in these women is of a long-standing nature.”

There are an average of 105 boys born for every 100 female births in nature. But in this study, women who had higher blood pressure and other signs of physical stress had four boys for every nine girls, while moms who were psychologically stressed had two boys for every three girls. All of the women in the study had healthy pregnancies.

Interestingly, this particular birth pattern has presented itself before — both in times of national crisis. “Other researchers have seen this pattern of a decrease in male births related to traumatic cataclysmic events,” Monk says. “One of them being President Kennedy’s assassination and the other being the September 11 terrorist attacks in New York City.”

Those who were stressed out during their pregnancies were also more likely to give birth prematurely compared to those who were not stressed. However, pregnant people with more mental stress also had more birth complications, such as longer labor, than those with physical stress.

On the flip side, social support for pregnant persons makes a huge difference. Those with someone to talk to or count on for help with their problems had a lesser risk for premature delivery. They also had a greater chance of delivering a baby boy.

“The support could be from family and friends,” Monk said. “It could be a sense of belonging in a religious community. It’s the sense of social cohesion and social connectedness which research suggests is a buffer against the experiences of stress. It means you take a break from it.”

Support for pregnant people and new parents is critical. The United States is currently the country with the most stressed out moms with the least support, according to research published earlier this year. There is a lack of support for working mothers in the U.S. For example, American mothers stand out in their experience of crushing guilt and work-family conflict.

Stress during pregnancy is harmful for both the person carrying the baby and the baby itself. Beyond influencing the sex of the baby, perinatal stress can also increase the chance for postpartum depression as well as the host of physical problems mentioned above.

While stress is, no doubt, a part of life for everyone — it’s crucial for pregnant people and new mothers and fathers to find the support at home and at work that they need during this time.

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