Which analgesic is generally avoided in late pregnancy due to potential risks to the fetus?

Aspirin is generally avoided in late pregnancy primarily due to its effects on the clotting mechanism and the risk of bleeding. It can inhibit platelet function and may lead to complications such as increased bleeding in both the mother and the fetus during delivery. Additionally, its use in the third trimester has been associated with potential adverse effects on the fetal cardiovascular system, such as premature closure of the ductus arteriosus, which can lead to pulmonary complications.

In contrast, ibuprofen and naproxen are also nonsteroidal anti-inflammatory drugs (NSAIDs) and are typically not recommended in the late third trimester for similar reasons, primarily related to cardiac and renal function in the fetus. However, acetaminophen is considered safer for short-term use during pregnancy as it does not pose the same risks for fetal bleeding or cardiovascular compromise. Therefore, while all NSAIDs should be used cautiously, aspirin is distinctly known for the specific contraindications in the late stages of pregnancy, making it the primary analgesic to avoid.