Headaches are a common complaint among pregnant women, along with other forms of mild-to-moderate pain often relieved by taking painkillers or analgesics. Common analgesics often used for pain-relief include NSAIDs, acetaminophen, and the stronger codeine-containing painkillers.
Non-steroidal anti-inflammatory drugs (NSAIDs) are one of the most commonly prescribed medications during pregnancy. They can be used to relieve fever, pain and/or various sorts of inflammatory conditions. Given the high use of both prescription and OTC NSAIDs, knowledge of any adverse effects associated with their use during pregnancy is of utmost importance.
NSAIDs are classified as either selective or non-selective, depending on their mode of action. Non-selective NSAIDs (aspirin, ibuprofen), exert their effect by inhibiting both the COX-I and COX-II inflammatory pathways, while selective NSAIDs (celecoxib) inhibit only the COX-II inflammatory pathway. The latter have no effect on platelet aggregation or the gastrointestinal tract and are generally considered safer.
To this day, acetylsalicylic acid (aspirin) remains the most thoroughly studied NSAID. Generally, low-dose (<3 g/dl) aspirin is not associated with increased risk of congenital anomalies, prematurity, low birth-weight, or miscarriages. Though it is still advised to avoid the use of aspirin near the end of the pregnancy (third trimester).
Another common non-selective NSAID is Ibuprofen, which is considered only safe when taken during the middle of pregnancy. Ibuprofen can be used in the second trimester (14 to 27 weeks), and should be avoided in the first (0 to 13 weeks) and third trimesters (28 weeks onward).
Research on newer NSAIDs, particularly the newer COX-II inhibitors is scant, with very few population studies.
The majority of conducted studies recommend stopping NSAIDs 6 to 8 weeks (2 months) prior to delivery, or during the third trimester. This reduces the risk of early closure or constriction of ductus arteriosus, persistent fetal pulmonary hypertension, intracranial hemorrhages, and renal toxicity in the fetus.
Another common analgesic (painkiller) and antipyretic (fever reducer), with no anti-inflammatory effects, commonly used in pregnancy is acetaminophen (paracetamol). Paracetamol on its own with no added ingredients is considered the safest possible painkiller for pregnant women suffering from headaches or other mild to moderate forms of pain. Some research has linked the use of paracetamol during pregnancy to wheezing in the newborn. This, however, has not been confirmed as the evidence of such a link remains unclear. The general consensus is that as long as it is not taken too often, the newborn should be fine.
Codeine and codeine-containing analgesics should be strictly avoided during pregnancy, unless otherwise recommended by the physician.