The fetal safety of thiopurines for the treatment of inflammatory bowel disease in pregnancy

J Obstet Gynaecol. 2013 Jan;33(1):1-8. doi: 10.3109/01443615.2012.716106.


Maintaining remission of inflammatory bowel disease (IBD) during pregnancy is critical for positive pregnancy outcomes. Conflicting data exist regarding the association between thiopurine use for IBD treatment in pregnancy and adverse pregnancy outcomes and this meta-analysis aims to clarify this association. A meta-analysis was performed of all original human studies reporting outcomes in pregnancy in patients receiving thiopurines. Nine studies satisfied the inclusion criteria and a total of 494 patients with IBD and 2,782 IBD controls were reported. When compared with healthy women, those receiving thiopurines had an increased risk for congenital malformations (RR 1.45; 95% CI 1.07-1.96; p = 0.02); however, when compared with IBD controls, there was no increased risk (RR 1.37; 95% CI 0.92-2.05; p = 0.1). These data provide support for thiopurines having a minimal risk, if any, to the fetus.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Abnormalities, Drug-Induced / etiology
  • Abortion, Spontaneous / chemically induced
  • Animals
  • Azathioprine / adverse effects*
  • Birth Weight / drug effects
  • Case-Control Studies
  • Female
  • Humans
  • Immunosuppressive Agents / adverse effects*
  • Inflammatory Bowel Diseases / drug therapy*
  • Mercaptopurine / adverse effects*
  • Pregnancy
  • Pregnancy Complications / drug therapy*
  • Pregnancy Outcome
  • Premature Birth / chemically induced


  • Immunosuppressive Agents
  • Mercaptopurine
  • Azathioprine