Women Who Work Long Hours During Pregnancy Are At Increased Risk Of Developing Stunted Fetuses, Japanese Research Suggests

Women who work long hours and night shifts during pregnancy are more likely to have stunted fetuses, according to a recent Japanese study.


The survey, conducted by Nagoya city university and the environment ministry, also said women were at greater risk of developing high blood pressure after pregnancy. The results were published in the Oct. 31 issue of the American journal of obstetrics, birth. The study covered about 100,000 pregnant women in Japan. A research team collected data on their working hours and night shifts, which also took into account the physical condition and delivery methods of pregnant women during childbirth.

Regardless of age, smoking or alcohol consumption, women who worked night shifts one to five times a month and worked 36 to 45 hours a week in the second and third trimester had a 1.56 times higher risk of mild hypertension than women who did not work. People who work 46 hours or more a week are at particular risk, about twice as much as those who don’t.


Those who worked 46 hours a week or more during the first trimester and worked one to six night shifts a month had about 1.3 times the risk of developing stunted fetuses compared to those who did not work. Those who worked 36 hours or more a week during pregnancy were also more likely to need tweezers, vacuum pumps or other methods that required medical equipment to help with labor.

“More and more women continue to work after marriage and even during pregnancy, but they should avoid working long hours for the health of their children and safer delivery,” said team member I, an obstetrician and gynecologist at Nagoya municipal university hospital.