In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to mesalamine may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What is mesalamine?
Mesalamine is an anti-inflammatory (reduces inflammation or swelling) prescription medication used to treat inflammatory bowel disease. Other names for mesalamine are mesalazine and 5-aminosalicylic acid (5ASA). Mesalamine can be taken orally (Apriso®, Asacol®, Delzicol®, Lialda®, Pentasa®) or rectally (Canasa®, Rowasa®, Pentasa®).

Should I stop taking mesalamine before I try to get pregnant?
You should not stop taking your medication without first speaking with your health care provider. It is important to consider the benefits of controlling your inflammatory bowel disease during pregnancy. Untreated inflammatory bowel disease increases the risk for complications for both the mother and the baby. For more information about inflammatory bowel disease in pregnancy, please see the MotherToBaby fact sheet Inflammatory Bowel Disease at http://mothertobaby.org/fact-sheets/inflammatory-bowel-disease-pregnancy/ or contact MotherToBaby toll-free at 1-866-626-6847.

Individuals break down medicines at different rates. If it is decided that you will stop your mesalamine before trying to get pregnant, it may take up to 6 days for the medication to clear your system.

Can taking mesalamine during my pregnancy cause birth defects?
Exposure to mesalamine is very unlikely to increase the chance for birth defects. There have been several studies, including one involving over 550 women exposed to mesalamine or a similar medication in the first trimester that have found no increased chance for birth defects.

Can exposure to mesalamine later in pregnancy cause other pregnancy complications?
There has been one case report of an infant born with kidney problems whose mother took mesalamine in the third and fifth month of the pregnancy. No conclusions can be made based on one case report. According to reports from one manufacturer, there have been no cases of kidney problems among sixty pregnancies in which the mother took mesalamine.

Can I take mesalamine while breastfeeding?
Mesalamine is found in breastmilk in small amounts. Reports of diarrhea occurring in breastfed infants suggest that some infants may be sensitive to mesalamine in the breastmilk. There is one report that suggests that this may even happen with rectal exposure in the mother. In contrast, there have also been reports of breastfed infants who did not have adverse effects. When taking mesalamine while breastfeeding, the nursing infant should be watched closely for changes in bowel activity. Be sure to talk to your health care provider about all questions regarding breastfeeding.

What if the father of the baby takes mesalamine?
There have been some reports of men who had lower sperm count while taking mesalamine but the sperm count returned to normal after stopping the medication. There are no studies looking at possible risks to a pregnancy when the father takes mesalamine. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet on Paternal Exposures and Pregnancy at http://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/pdf/.

MotherToBaby is currently conducting a study looking at inflammatory bowel disease and the medications used to treat this condition in pregnancy. If you are interested in taking part in this study, please call 1-877-311-8972 or sign up at http://mothertobaby.org/join-study/.

References:

  • Ban L et al. 2014. Limited risks of major congenital anomalies in children of mothers with IBD and effects of medications. Gastroenterology 146 (1):76-84.
  • Chermesh I & Eliakim R. 2004. Mesalazine-induced reversible infertility in a young male. Dig Liver Dis 36:551-2.
  • Colombel J-F et al. 1994. Renal insufficiency in infant: side-effect of prenatal exposure to mesalazine? Lancet 344(8922):620-621.
  • Marteau P & Devaux CB. 1994. Mesalazine during pregnancy. Lancet 344(8938):1708-1709.
  • Nelis GF. 1989. Diarrhoea due to 5-aminosalicylic acid in breastmilk. Lancet 1:383.
  • Shin T et al. 2014. Inflammatory bowel disease in subfertile men and the effect of mesalazine on fertility. Syst Biol Reprod Med 60(6); 373-376.
  • Silverman DA et al. 2005. Is mesalazine really safe for use in breastfeeding mothers? Gut 54: 170-1.