Baricitinib and Abrocitinib Safety in Pregnancy
Both baricitinib and abrocitinib should be avoided during pregnancy due to insufficient human safety data and evidence of animal teratogenicity, and women of childbearing age must use effective contraception while taking these medications.
Guideline-Based Recommendations
The most recent EULAR 2025 guidelines explicitly state that drugs with insufficient safety data on use in pregnancy should be avoided until further evidence is available—this specifically includes baricitinib and abrocitinib 1. The 2025 expert consensus on JAK inhibitors reinforces that pregnancy and lactation remain contraindications, with women of childbearing age required to adhere to effective contraception due to evidence of animal teratogenicity 2.
FDA Drug Label Evidence
Abrocitinib (CIBINQO)
The FDA label clearly states that available data from clinical trials are not sufficient to establish a drug-associated risk for major birth defects, miscarriage, or other adverse maternal or fetal outcomes 3. Critical animal data shows:
- Skeletal variations in rat offspring at 11× the maximum recommended human dose (MRHD)
- Embryofetal lethality at 17× MRHD
- Dystocia with prolonged parturition and reduced offspring body weights at 11× MRHD
- Markedly decreased postnatal survival at 17× MRHD
- Potential impairment of female fertility (reversible after cessation) 3
A pregnancy exposure registry exists (1-877-311-3770) for monitoring outcomes 3.
Baricitinib
While specific FDA label data for baricitinib is not provided in the evidence, the guideline recommendations place it in the same category as abrocitinib regarding pregnancy avoidance 1.
Limited Human Experience
Only one case report exists describing baricitinib exposure during pregnancy: a 43-year-old woman exposed through the first 17 weeks of gestation who delivered a healthy infant with normal fetal growth and no macroscopic abnormalities 4. However, a single positive outcome is insufficient to establish safety, and this case actually reinforces the importance of contraception counseling.
Lactation Considerations
Both medications should be avoided during breastfeeding 1. For abrocitinib specifically, the FDA recommends not breastfeeding during treatment and for one day after the last dose due to serious adverse findings in adults (infections, malignancy, thrombosis) and animal data showing drug concentrations in milk 5× higher than plasma 3.
Clinical Implementation
Before initiating treatment:
- Confirm negative pregnancy test in women of reproductive potential
- Establish reliable contraception (barrier methods plus hormonal or intrauterine device)
- Counsel on the requirement to discontinue immediately if pregnancy occurs
- Provide pregnancy registry contact information
If accidental exposure occurs:
- Discontinue medication immediately upon pregnancy confirmation
- Enroll in pregnancy exposure registry
- Arrange close obstetric monitoring with detailed fetal anatomic surveys
- Document exposure timing and duration
Key Caveats
The animal teratogenicity data occurred at supratherapeutic doses, but the lack of adequate human data prevents risk quantification. The single positive pregnancy outcome with baricitinib 4 should not provide false reassurance—this represents insufficient evidence for safety determination, particularly given the consistent guideline recommendations against use 2, 1.