The effects of azathioprine on birth outcomes in women with inflammatory bowel disease (IBD).

AIM

To investigate the effects of azathioprine/6-mercaptopurine (AZA/6-MP) on birth outcomes in women with inflammatory bowel disease (IBD).

METHODS

Details of pregnant women with IBD were obtained through an ObstetriX Database in 3 major teaching hospitals in Sydney from 1996 to 2006. Medical records were reviewed. Birth outcomes of interest were single live births, low birth weight (LBW) at term (<2500 g), preterm births (<37 weeks gestation), neonatal adverse outcomes, and congenital anomaly. Placental blood flow during third trimester of pregnancy was measured using arterial Doppler ultrasonography, where available.

RESULTS

All women had IBD diagnosed before pregnancy. 19 births were exposed to AZA/6-MP. 74 births that were never exposed to AZA/6-MP were selected as controls. Preterm birth was seen in 26.3% of the exposed group as compared to 13.5% of controls (p<0.001). However, in univariate analysis, preterm birth was not associated with AZA/6-MP (OR=2.28; CI: 0.67-7.73). There was 1 neonatal adverse outcome in the exposed group as compared to 4 in controls (5.3% vs 5.4%, p=0.97). One congenital anomaly was seen in each group (p=0.27). No LBW at term was seen in either group. Placental blood flow in 4 women exposed to AZA/6-MP was normal.

CONCLUSION

The use of AZA/6-MP during pregnancy in IBD women was not associated with an increased risk of preterm birth, LBW at term, neonatal adverse outcomes and congenital anomalies.