Ibuprofen
NSAID pain reliever (Advil, Motrin). Avoid after 20 weeks due to fetal kidney and ductus arteriosus risks; FDA warning issued Oct 2020.
Quick answer
Avoid ibuprofen after 20 weeks of pregnancy. NSAIDs can cause fetal kidney problems, oligohydramnios, and (after 30 weeks) premature closure of the ductus arteriosus. FDA issued a formal warning in October 2020. Acetaminophen is the safer first-line pregnancy pain reliever.
INCI name
Ibuprofen
CAS number
15687-27-1
Also known as
Advil, Motrin, Brufen, ibuprofen sodium
Formula
C13H18O2
What is Ibuprofen?
What ibuprofen is
Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID) sold OTC as Advil, Motrin, and many store brands. It works by inhibiting cyclooxygenase (COX-1 and COX-2) enzymes, reducing prostaglandin synthesis — which produces its pain-relieving, anti-inflammatory, and fever-reducing effects1.
Why ibuprofen is avoided in pregnancy (especially after 20 weeks)
The FDA issued a formal warning in October 2020 recommending that pregnant women avoid NSAIDs at 20 weeks and beyond, citing growing evidence of fetal harm2. Specific concerns:
- Fetal kidney effects (20+ weeks). NSAID-induced reduction in fetal urine output causes oligohydramnios (low amniotic fluid volume), with downstream effects on lung development, joint contractures, and other complications3.
- Premature closure of ductus arteriosus (30+ weeks). The fetal ductus arteriosus is kept open by prostaglandins; NSAID-driven prostaglandin reduction can cause premature closure, leading to neonatal pulmonary hypertension.
- Earlier-pregnancy concerns. Some studies suggest NSAID use in the first trimester may slightly increase miscarriage risk, though evidence is mixed4.
Trimester-specific guidance
- First trimester: Avoid if possible; mixed evidence on miscarriage risk. Use acetaminophen instead for pain/fever.
- 20 weeks and later: Avoid entirely per FDA recommendation. The kidney and ductus arteriosus concerns become clinically significant.
- Third trimester: Strictly contraindicated except in specific medical scenarios where the OB has weighed risks vs. benefits.
Other NSAIDs to avoid
The same warning applies to all NSAIDs:
- Naproxen (Aleve)
- Aspirin (full-dose; low-dose 81 mg prescribed for preeclampsia prophylaxis is a separate clinical scenario)
- Diclofenac (Voltaren)
- Indomethacin
- Celecoxib (Celebrex)
Safer pregnancy pain relief
Acetaminophen (Tylenol) is the first-line OTC pain reliever and fever reducer during pregnancy. ACOG considers it safe at recommended doses across all trimesters. (Recent literature on possible neurodevelopmental associations with chronic high-dose use exists but ACOG still considers acetaminophen the safest OTC analgesic; use the lowest effective dose.) See the [Acetaminophen page](/ingredients/acetaminophen/) for details2.
Is Ibuprofen safe while breastfeeding?
Ibuprofen is compatible with breastfeeding — transfer to milk is minimal.
When to talk to your OB
If you used a product containing Ibuprofen before learning you were pregnant, mention it at your next prenatal visit — but most topical cosmetic exposures are not a cause for panic. For prescription exposures or specific concerns, contact your OB or midwife directly.
Sources
- U.S. National Library of Medicine. Ibuprofen. PubChem. View source →
- U.S. Food and Drug Administration. (2020). FDA recommends avoiding use of NSAIDs in pregnancy at 20 weeks or later. FDA Drug Safety Communication. View source →
- Bloor M, Paech M. (2013). Nonsteroidal anti-inflammatory drugs during pregnancy and the initiation of lactation. Anesthesia & Analgesia. View source →
- Nakhai-Pour HR, Broy P, Sheehy O, Bérard A. (2011). Use of nonaspirin nonsteroidal anti-inflammatory drugs during pregnancy and the risk of spontaneous abortion. CMAJ. View source →