Allie, a 37-year-old bottlenose dolphin, has entered her third trimester of a 12-month pregnancy. She is expected to give birth in June.

Gisele Bündchen is spending some time outdoors with her little one.

In Tjitske Zaat and colleagues’ study,1 fewer than 3% of patients in natural menstrual cycles were administered exogenous progesterone for luteal phase support. In their Comment,2 Shari Mackens and ...