Pregnant women in their first trimester are more active earlier in the day. This, from researchers at Washington University in St. Louis.

This study followed 39 women who wore wristwatches that tracked their daily activity for two weeks prior to conception, and again when they found out they were pregnant, up until delivery.

The researchers found that pregnant women advance their daily schedule by a few hours during their first trimester. And while they don’t appear to be more active in early pregnancy, they do shift total activity to earlier in the day.

The team says that this shift in schedule and activity is likely due to a combination of pregnancy hormones, fatigue, and the hard work that goes into carrying a baby.


Martin-Fairey, C. A., Zhao, P., et al. (2019, April 24). Pregnancy induces an earlier chronotype in both mice and women. Journal of Biological Rhythms. Retrieved from