THE SAFETY OF MESALAMINE IN HUMAN-PREGNANCY - A PROSPECTIVE CONTROLLED COHORT STUDY

Background & Aims: Mesalamine is a first-line drug in the treatment of inflammatory bowel disease. Information regarding human pregnancy exp erience with mesalamine has been scarce and uncontrolled despite its f requent use in women of childbearing age. The aim of this study was to examine the fetal safety of mesalamine. Methods: The Motherisk Progra m prospectively enrolled and followed up 165 women exposed to mesalami ne during pregnancy, 146 of whom had first trimester exposure. Pregnan cy outcome was compared with that of a matched control group, who were counseled for nonteratogenic exposure. Results: There was no increase in major malformations (1 of 127 [0.8%] for mesalamine vs. 5 of 131 [ 3.8%] for nonteratogenic controls; P = 0.23). There was an increase in the rate of preterm deliveries (13.0% for mesalamine vs. 4.7% for non teratogenic controls; P = 0.02), a decrease in the mean maternal weigh t gain during pregnancy (13.1 +/- 6.3 kg for mesalamine vs. 15.6 +/- 6 .0 kg for nonteratogenic controls; P = 0.0002), and a decrease in the mean birth weight (3253 +/- 546 g for mesalamine vs. 3461 +/- 542 g fo r nonteratogenic controls; P = 0.0005). There were no significant diff erences in the maternal obstetric history, rates of live births, misca rriages, pregnancy terminations, ectopic pregnancies, delivery method, or fetal distress between the groups. Conclusions: This study suggest s that mesalamine does not represent a major teratogenic risk in human s when used in the recommended doses.