Mette Julsgaard, MD, on IBD Medications During Lactation
Dr Julsgaard led the group that studied and developed consensus statements on the subject of IBD medications safe to use during lactation.
Mette Julsgaard, MD, PhD, is a clinical associate professor in the Department of Clinical Medicine - Hepatology and Gastroenterology at Aarhus University in Aarhus, Denmark.
TRANSCRIPT:
Hi, I am Mette Julsgaard, a gastroenterologist from Aarhus University Hospital, Denmark. I was European lead on the global consensus on the management of IBD in pregnancy. Today I will talk about medication during lactation.
When it comes to breastfeeding, management for women with IBD closely follows pregnancy recommendations. Most medications are considered safe during lactation. This image shows how medication, specifically monoclonal antibodies and small molecules, are transferred from maternal blood into breast milk during breastfeeding. One of the key measures then evaluating medication safety during breastfeeding is the relative infant dose, or RID. It estimates how much of the drug the infant is exposed to through breastfeeding. A RID below 10% is, in general, considered low risk. For IBD medications, the RID is typically well under this threshold. This figure shows that while monoclonal antibodies are present in the mother's bloodstream, only a tiny amount is transferred into breast milk. And even then, most of it is broken down in the infant's gut, and in theory, only a minimal amount can be absorbed, resulting in very low infant exposure. Another important point is that in infants exposed to biologics during pregnancy, maternal breastfeeding did not affect neonatal clearance of the drug. This clearly emphasizes that treatment with biologics is compatible with breastfeeding.
We recommend breastfeeding as it is not associated with an increased risk of disease activity in women with IBD. This recommendation is supported by a meta-analysis including more than 500 infants, which found no significant impact of breastfeeding on postpartum disease activity. Early data suggested a higher risk of disease activity, but this was actually linked to mothers stopping their medication, not breastfeeding itself.
Infants born to mothers on anti-TNF therapy who breastfeed do not have an increased risk of infections. So it's important that we reassure and counsel our patients about this. Breastfeeding is considered safe for mothers taking 5-ASAs, thiopurines, corticosteroids, and biologics like anti-TNF, anti-integrins, and anti-IL 23s and biosimilars to these biologics. The relative infant dose is below 1% across all broad categories and studies shows no difference in infant growth, infant development, and risk of infections during the first year of life between breastfed and nonbreastfed infants.
Mothers with IBD on S1Ps or JAK inhibitors should avoid breastfeeding. There's no human safety data on breastfeeding with S1Ps, ozanimod, or etrasimod. Although their high protein binding, in theory suggests minimal transfer into breast milk, breastfeeding should be avoided until we have human data confirming its safety during lactation. For JAK inhibitors, tofacitinib showed higher levels in human breast milk than serum. Although the relative infant dose is low— 3.4%— it is still markedly higher than for other IBD drugs and a high gut bioavailability of tofacitinib may also increase infant absorption.
In conclusion, most IBD drugs are safe during pregnancy. However, due to limited or no human safety data and unknown immune effects of the suckling infant, formula feeding is recommended when treatment with an S1P or a JAK inhibitor is needed. The same applies to methotrexate; despite a low relative infant dose, its active metabolite is detectable in breast milk. Thank you.
