Ibuprofen

Pregnancy

Birth defects: MotherToBaby reports that several studies did not find a higher overall chance, while a few suggested an increase in gastroschisis and some reported small increases in heart defects from NSAID prescriptions. Bird et al. 2009 was a case-control study with 485 gastroschisis cases and 4,967 controls; ibuprofen use was associated with AOR 1.61 (95% CI 1.23-2.10). Baldacci et al. 2024 pooled 18 observational studies covering 751,954 pregnancies and reported an ibuprofen-gastroschisis RR of 1.42 (95% CI 1.26-1.60); the authors noted that associations were significant only in particular subgroups. Neither abstract provides an absolute risk for an individual pregnancy. MotherToBaby's statement of less than 1% could not be traced to an absolute-risk calculation in the primary abstracts, so that number is not repeated. A 2026 Israeli retrospective register cohort included 264,858 singleton pregnancies, of which 20,202 were NSAID-exposed and 5.1% had ibuprofen exposure; it found no association between first-trimester NSAID exposure, including individual agents, and major congenital malformations overall. It relied on pharmacy dispensing and noted possible misclassification from over-the-counter use. Casey et al. 2026 included 643 isolated clubfoot cases and 2,037 controls and found elevated odds ratios of 1.22 to 1.44 for ibuprofen across laterality groups; this is a specific observational outcome, not proof of causation. Miscarriage: Li et al. 2003 followed 1,055 women; 53 reported NSAID use, and prenatal use was associated with miscarriage (adjusted HR 1.8, 95% CI 1.0-3.2), with a stronger association around conception or after more than one week of use. Nakhai-Pour et al. 2011 compared 4,705 miscarriage cases with 47,050 controls and reported an association for ibuprofen prescriptions (OR 2.19, 95% CI 1.61-2.96). Daniel et al. 2014 studied 65,457 pregnancies and found no independent association for nonselective NSAIDs overall (adjusted HR 1.10, 95% CI 0.99-1.22), while Dathe et al. 2018 compared 1,117 first-trimester ibuprofen exposures with 2,229 non-exposed pregnancies and found similar miscarriage rates (adjusted HR 0.85, 95% CI 0.65-1.11). The studies are observational and differ in exposure timing, prescription versus reported use, and adjustment for the condition being treated. Later pregnancy: FDA labeling describes fetal kidney dysfunction and low amniotic fluid from about 20 weeks, with dose and duration limits through about 30 weeks and avoidance thereafter; MHRA and NHS SPS use a 28-week cutoff for systemic NSAIDs.

Breastfeeding

LactMed's Aug 15, 2025 review reports that two early studies found ibuprofen undetectable in milk after maternal doses of 400 mg twice daily or 400 mg every six hours. A later sensitive assay detected small amounts after six 400 mg doses over 42.5 hours. In a study of 13 mothers taking an average of about 1,012 mg daily, mean milk concentration was 361 mcg/L and mean relative infant dose was below 0.38%; the estimated infant dose was about 0.2% of a pediatric dose. Rigourd et al. 2014 studied 13 milk samples and reported a relative infant dose below 0.38% on average, with a range of 0.04% to 1.53%. Townsend et al. 1984 found no measurable milk levels in 12 mothers taking 400 mg every six hours for 24 hours. LactMed found no relevant published infant-level information and lists at least 23 reported breastfed infant exposures without adverse effects. NHS SPS calls ibuprofen the NSAID of choice but says published information is very limited and advises monitoring for vomiting and diarrhea. Gatti et al. 2026 reviewed 34 studies on NSAIDs and acetaminophen during lactation and concluded there was not enough data to establish whether lactating women should use NSAIDs; the conclusion is class-wide, and its abstract does not give an ibuprofen-specific adverse-event rate. In a 2024 randomized trial, 200 women after vaginal delivery were assigned to scheduled or as-needed paracetamol plus ibuprofen; breastfeeding rates were 98% versus 88%, with no reported side effects or adverse outcomes in either group. This trial measured postpartum pain-management outcomes, not long-term infant safety.

What was tested

Pregnancy evidence reviewed includes observational cohorts, prescription-register and interview-based case-control studies, and a systematic review/meta-analysis of gastroschisis studies. These studies measure different outcomes and cannot fully separate medication effects from the conditions that led to use. The 2026 Israeli cohort used pharmacy dispensations and included live births, stillbirths, and fetal-malformation terminations, with possible missed over-the-counter exposure. Breastfeeding evidence includes small milk-level studies, case reports or follow-up, specialist guidance, and a postpartum randomized trial of 200 women. The 2026 lactation review covered 34 studies across multiple NSAIDs and acetaminophen, not ibuprofen alone. No ibuprofen-specific randomized pregnancy trial was identified in the sources reviewed.