Can you take certolizumab pegol while breastfeeding?
What LactMed says
The National Library of Medicine’s own summary, quoted in full. We do not write a verdict of our own on this question, and we do not compress theirs into a label.
Certolizumab is excreted into breastmilk in some, but not all, women in small amounts. It is also likely to be partially destroyed in the infant's gastrointestinal tract and absorption by the infant is probably minimal. Polyethylene glycol is not excreted into breastmilk. Numerous experts and professional guidelines have stated that the drug is a low risk to the nursing infant and acceptable to use during breastfeeding. Anti-TNF agents appear to reduce the levels of tumor necrosis factor and IP-10 in the milk of mothers with inflammatory bowel disease in the early postpartum period. This reduction in TNF might lead to decreased milk production, so extra lactation support might be necessary in women taking certolizumab pegol.
Quoted from Certolizumab Pegol — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised July 15, 2026.
What LactMed would consider instead
LactMed ends this record by naming the drugs it would consider in place of certolizumab pegol. Whether any of them fits depends on what you are treating — this is the database’s list, not a recommendation from us.
- Adalimumab
- Infliximab
- Etanercept
- Tocilizumab
How much certolizumab pegol gets into breastmilk
Maternal Levels. One woman received certolizumab pegol 400 mg by subcutaneous injection every 4 weeks during pregnancy and postpartum. The last dose during pregnancy was 1 week prior to delivery. Breastmilk samples were collected 1 and 2 weeks postpartum and 4 hours, 3 days and 6 days after the first postpartum dose which was given at 3 weeks postpartum. Certolizumab was undetectable (<410 mcg/L) in all 5 samples.
Two women were receiving certolizumab pegol 200 mg every two weeks. Certolizumab was undetectable (<0.6 mg/L) in breastmilk one hour after the dose in both women and 4 hours after the dose in one of them.
Seventeen nursing mothers who were taking certolizumab pegol for an inflammatory condition and were at least 6 weeks postpartum had certolizumab measured in their breastmilk at least 8 times over a dosage interval. The maternal dose was 200 mg every 2 weeks in 16 women and 400 mg every 4 weeks in another. Out of 137 breastmilk samples, 77 had no detectable certolizumab and 4 mothers had no detectable (<32 mcg/L) certolizumab in milk at any time point, including the mother who received the 400 mg dose. Of the 13 other mothers, the highest concentrations found were 76 mcg/L, which was found in one woman at 6 and 8 days after the dose, and 65 and 66 mcg/L in another at 4 and 6 days after the dose, respectively. All other mothers with detectable certolizumab had milk levels that were less than 64 mcg/L. The median time of peak milk levels was 5.05 days (range 2.9 to 11.9 days). The estimated average daily infant dose ranged from 0 to 0.0104 mg/kg daily. No measurable levels of total polyethylene glycol were detected in 134 of 137 breast milk samples; 3 samples had indeterminate results upon retesting.
In a multi-center study of women with inflammatory bowel disease in pregnancy (the PIANO registry), 13 women receiving certolizumab pegol provided milk samples at 1, 12, 24, and 48 hours after drug administration. Some also provided samples at 72, 96, 120, and 168 hours after drug administration. Three of the women had detectable (>0.01 mg/L) certolizumab levels in milk. Peak concentrations in breastmilk ranged from 0.27 to 0.29 mg/L and occurred at 12 to 48 hours after the dose.
A woman in Japan with rheumatoid arthritis was treat with certolizumab pegol (dosage not stated) beginning at 28 weeks of pregnancy and continuing postpartum. Breastmilk samples taken before delivery, at delivery, and 4 and 8 weeks postpartum all contained unmeasurable (<0.1 mg/L) amounts of certolizumab.
Infant Levels. One woman received certolizumab pegol 400 mg by subcutaneous injection every 4 weeks during pregnancy and postpartum. The last dose during pregnancy was 1 week prior to delivery. At birth, her infant had a serum concentration of 1.02 mg/L. At one month of age, her breastfed (extent not stated) infant had a serum concentration of 0.84 mg/L seven days after the previous injection.
In a study reported in the product information, plasma certolizumab concentrations were collected 4 weeks after birth in 9 breastfed infants whose mothers had been currently taking certolizumab pegol (regardless of being exclusively breastfed or not). Certolizumab was not measurable (<32 mcg/L) in infant plasma.
What has been seen in breastfed infants
Eight women who received certolizumab pegol during pregnancy and postpartum breastfed (extent not stated) their infants. No mention was made of side effects in the infants.
Seventeen mothers received certolizumab pegol for an inflammatory condition and breastfed their infants. During a study period starting at least 6 weeks postpartum and after at least 3 doses of certolizumab pegol, 8 of the infants experienced 11 adverse effects. None of the infants had any unusual or serious adverse reactions attributed to the drug and all effects were consistent with events typically experienced by infants of the same age, such as upper respiratory infection, Candida infection, or vomiting.
In a multi-center study of women with inflammatory bowel disease in pregnancy (the PIANO registry), 54 women received certolizumab pegol while breastfeeding their infants. Among those who received certolizumab or another biologic agent while breastfeeding, infant growth, development or infection rate was no different from infants whose mothers received no treatment. An additional 67 women received a biologic agent plus a thiopurine. Infant outcomes were similar in this group.
Six women being treated with certolizumab pegol for uveitis during pregnancy and postpartum breastfed their infants (extent not sated). One of the mothers also took hydroxychloroquine. In 6 months of follow-up, no infants had any infections, and all had inactivated vaccines specified in the Spanish national immunization program (hepatitis B, diphtheria, tetanus and acellular pertussis [DTaP], inactivated poliovirus, Haemophilus influenzae type B conjugate, pneumococcal conjugate and meningococcal C conjugate). One of the infants also received rotavirus vaccine. No complications were seen with any of the vaccines.
Three women were treated with certolizumab, two during pregnancy and breastfeeding and one during breastfeeding alone. Infant follow-up at 6, 18 and 32 months, respectively, found no adverse reactions and normal growth and neurodevelopment in the infants.
A national prospective registry of patients with rheumatic diseases who were treated with biological DMARDs was conducted in Spain. One whose mother was taking certolizumab was breastfed (extent not stated) with no mild or severe adverse events reported in the infant.
A retrospective study of mothers in Spain taking certolizumab pegol for psoriasis found 11 women who breastfed (extent not stated) their infants during therapy. No adverse events were reported in breastfed infants.
An analysis of the US Food and Drug Administration’s FAERS database of 7,022 spontaneous adverse reaction reports of anti-TNF drugs found that they may cause an increased risk of lactation insufficiency and disorders. Drugs that were studied included adalimumab, infliximab, golimumab, certolizumab, and etanercept. The authors noted that TNF alpha is involved in milk production, adding biological plausibility to the findings.
A retrospective, single-center study of patients treated with certolizumab pegol during lactation found four infants who were exposed. No infant experienced serious infections, vaccine-related complications, or developmental delay during follow-up (mean 39.3 months). Vaccinations were administered according to the Turkish National Immunization Schedule appropriate for the infants' ages during follow-up.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take certolizumab pegol while breastfeeding?
Certolizumab is excreted into breastmilk in some, but not all, women in small amounts. The full record is quoted on this page, and the decision is one to make with the person who prescribed it — LactMed itself states it is not a substitute for professional judgement.
What can I take instead of certolizumab pegol while breastfeeding?
LactMed lists Adalimumab, Infliximab, Etanercept, Tocilizumab as alternate drugs to consider. That is the database's own list for this drug — whether any of them suits you depends on what you are treating.
Does certolizumab pegol pass into breastmilk?
LactMed's measured drug levels for certolizumab pegol are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking certolizumab pegol?
LactMed does not frame its records that way — it reports measured drug levels in milk and what has been observed in breastfed infants, which is what this page quotes. "Pump and dump" advice for a specific drug and dose should come from your clinician or a pharmacist, not from a general rule.
More on certolizumab pegol
LactMed states that the information it presents is not a substitute for professional judgement, and that you should consult your healthcare provider for breastfeeding advice related to your particular situation. Nothing on this page is medical advice.