Use should be avoided during the third trimester of pregnancy.
Prior to third trimester: Use only if potential benefit justifies the potential risk to the fetus.

US FDA pregnancy category: C

Comments: Avoid use in late pregnancy as it may cause premature closure of the ductus arteriosus.

Animal studies have failed to reveal evidence of developmental abnormalities. Administration of nonsteroidal anti-inflammatory drugs (NSAIDs) during the third trimester of pregnancy may cause significant adverse effects, including premature closure of the fetal ductus. Animal studies with other prostaglandin synthesis inhibitors revealed evidence of increased dystocia, delayed parturition, and decreased pup survival during labor and delivery. There are no controlled data in human pregnancy.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

See references

Salicylic acid, the primary metabolite of this drug, has been shown to appear in human milk in concentrations approximating the maternal blood level. A nursing infant may ingest 30% to 80% as much salicylate per kilogram body weight as the mother is taking. The excretion of salicylate into breast milk increases disproportionately as the maternal dose increases. Reye's syndrome is associated with aspirin administration to infants with viral infections, but the risk of Reye's syndrome from salicylate in breast milk is unknown. An alternate drug is preferred over this drug during breastfeeding.

Caution is recommended.
-According to some authorities: Use is not recommended.

Excreted into human milk: Unknown
Excreted into animal milk: Data not available

Comments: The effects in the nursing infant are unknown.

See references