Biologics in pregnancy-for the obstetrician

Abstract

Key content The authors discuss commencing biologics in pregnancy and the potential side effects. Infection is a particular risk, which may be atypical or present atypically. While there is no evidence of teratogenicity, these drugs cross the placenta and neonatal cord drug levels may exceed those of maternal drug levels. If possible, anti-tumour necrosis factor (TNF) agents should be discontinued midtrimester but the gestation to which each drug can be used is slightly different. Neonates exposed in utero to anti-TNF agents beyond the recommended gestation should not be given live attenuated vaccines for the first 6 months of life and any infections promptly treated. Data are lacking on the long-term effects of biologics on children exposed in utero. However, the benefits of controlling active autoimmune disease in the mother often outweigh the small risk to the exposed infants. Learning objectives To know the biologics most commonly used in pregnancy. To understand the literature regarding safety of the common biologics in pregnancy. To be able to counsel a woman taking a biologic about the potential benefits and risks of taking it at different gestations. To be able to counsel a woman receiving biologics in pregnancy about vaccinations for her baby after birth. Ethical issues Biologic agents are relatively new drugs that are being increasingly used in young women because of their perceived ‘fertility sparing’ benefits despite a lack of high quality evidence. Most women who have been prescribed biologics are often refractory to other treatments, and therefore these agents are required for disease control. The decision to continue or discontinue these drugs in pregnancy, especially late pregnancy, is particularly contentious. The long-term effect of biologics on infants exposed in utero is not known and the decision to use these drugs has to be balanced against the risk of severe maternal flares.