Exposure to thioguanine during 117 pregnancies in women with inflammatory bowel disease

BACKGROUND: Safety of thioguanine in pregnant patients with inflammatory bowel disease (IBD) is sparsely recorded. This study was aimed to document the safety of thioguanine during pregnancy and in birth. METHODS: In this multicenter case series, IBD patients treated with thioguanine during pregnancy were included. Data regarding disease and medication history, pregnancy course, obstetric complications and neonatal outcomes were collected. RESULTS: Data on 117 thioguanine-exposed pregnancies in 99 women were collected. Most (78%) had Crohn's disease and the mean age at delivery was 31 years. In eighteen pregnancies (15%) IBD flared. Obstetric and infectious complications were seen in 15% (n=17) and 7% (n=8) of pregnancies, respectively. Ten pregnancies (8.5%) resulted in a first trimester miscarriage and one in a stillbirth at 22 weeks gestational age. Congenital abnormalities were observed in one induced abortion (trisomy 21) and in one of the live-born children (cleft palate) . In total 109 neonates were born from 101 singleton pregnancies and 4 twin pregnancies. In the singleton pregnancies, ten children were born prematurely and ten were born small for gestational age. Screening for myelosuppresion was performed in sixteen neonates (14.7%); two had anemia in umbilical cord blood. All outcomes were comparable to either the general Dutch population or to data from 3 Dutch cohort studies on the use of conventional thiopurines in pregnant IBD patients. CONCLUSION: In this large case series the use of thioguanine during pregnancy is not associated in excess with adverse maternal or neonatal outcomes