Most airlines and medical professionals recommend that healthy pregnant women stop flying by the end of the 36th week (the beginning of the 9th month) for single pregnancies. For multiple pregnancies (twins/triplets), the limit is usually earlier, at 32 weeks. These restrictions are not because flying is inherently dangerous to the baby, but to prevent the logistical and medical risks of going into labor while in flight. Most carriers, such as British Airways and Delta, require a medical certificate or a "fit to fly" letter from a doctor if you are traveling after the 28th week. In 2026, some airlines have slightly different rules—for example, Emirates and Etihad often allow travel up to the 36th week but are very strict about documentation. It is also important to note that the return flight must also fall within these limits. Always consult your OB-GYN before booking, as certain complications like high blood pressure or a history of premature labor may lead to an earlier "no-fly" recommendation.