(CNN) – Could stress during pregnancy be linked to more girl babies?
A study published Monday National Academy of Sciences found fewer boys were born to stressed out moms-to-be.
The lead author says male fetuses are more vulnerable — and long term stress could pay a role in pregnancies.
The study found four boys were born for every nine girls when the mother had high blood pressure and other signs of physical stress.
Nature typically stacks the gender pool at 105 males to 100 females.
The risk of preterm birth also went up with higher stress levels.
The opposite results were found when pregnant women received support from family and friends.
Stress is a normal part of life — and during pregnancy.
Getting plenty of sleep, eating healthy, and exercising can help minimize the effects of stress.