Air Force pilots and aircrew who are pregnant will no longer be allowed to fly during their first trimester under revised flight rules announced by the service Tuesday. The move is one of several updates to rules for pregnant women that both restrict and loosen when they can fly.

None of the changes were prompted by any specific cases involving pregnant airmen, said Rose Riley, an Air Force spokeswoman. The new rules, she said, bring the Air Force guidelines more in line with other military branches’ policies on when pregnant service members can fly.

In 2022, the service began allowing pregnant women in flight roles to apply for waivers to keep flying all the way from their first trimester through the 28th week of their pregnancy, Riley told Task & Purpose.

The new rules change that window. Now, pregnant aircrew members cannot be approved to fly during their first trimester when the risk of a miscarriage is highest, she said.