Advil is a brand name for ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, fever, and inflammation. According to WebMD [2], pregnant women should avoid taking ibuprofen in the last three months of pregnancy as it may harm the unborn baby. However, it may be safe to take in the first six months of pregnancy, but only if a doctor recommends it. The website also suggests that pregnant women should avoid taking any NSAIDs, including ibuprofen, for more than a few days at a time, except under a doctor's supervision.

The Advil website [3] also states that pregnant women should avoid taking Advil after 30 weeks of pregnancy, as it may cause harm to the unborn baby. However, it also states that pregnant women may take Advil before 30 weeks of pregnancy if a doctor recommends it. The website advises pregnant women to talk to their doctor before taking Advil or any other medication during pregnancy.

Drug Patent Watch [1] provides information on the expiration date of Advil's patent, but it does not offer any information on the safety of Advil during pregnancy.

In conclusion, pregnant women should avoid taking Advil after 30 weeks of pregnancy and should only take it before 30 weeks of pregnancy if a doctor recommends it. Pregnant women should also avoid taking any NSAIDs, including ibuprofen, for more than a few days at a time, except under a doctor's supervision. It is important for pregnant women to talk to their doctor before taking any medication during pregnancy.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ADVIL
[2] https://www.webmd.com/baby/pain-relievers-that-are-safe-during-pregnancy
[3] https://www.advil.com/advil-safety/advil-and-pregnancy/