This sheet is about exposure to mesalamine in pregnancy and while breastfeeding. This information is based on published research studies. It should not take the place of medical care and advice from your healthcare provider.
What is mesalamine?
Mesalamine (also known as mesalazine) is an anti-inflammatory medication (reduces inflammation or swelling) that has been used to treat ulcerative colitis and inflammatory bowel disease (IBD). It belongs to a class of medications called 5-aminosalicylic acids (5-ASA). Mesalamine has several brand names and can be taken in different ways. Some brands taken by mouth (orally) include Apriso®, Asacol®, Delzicol®, Lialda®, and Pentasa®. Other brands are used rectally (as a suppository or enema), such as Canasa®, Rowasa®, and Pentasa®.
Sometimes when women find out they are pregnant, they think about changing how they take their medication, or stopping their medication altogether. However, it is important to talk with your healthcare providers before making any changes to how you take your medication. When left untreated, IBD increases the risk of complications for both the woman who is pregnant and the fetus. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy. For more information about IBD, please see the MotherToBaby fact sheet at https://mothertobaby.org/fact-sheets/inflammatory-bowel-disease-pregnancy/
I take mesalamine. Can it make it harder for me to get pregnant?
Studies have not been done to see if mesalamine can make it harder to get pregnant.
Does taking mesalamine increase the chance of miscarriage?
Miscarriage is common and can occur in any pregnancy for many different reasons. One study of 146 women who used mesalamine in the first trimester did not find a higher chance of miscarriage.
Does taking mesalamine increase the chance of birth defects?
Birth defects can happen in any pregnancy for different reasons. Out of all babies born each year, about 3 out of 100 (3%) will have a birth defect. We look at research studies to try to understand if an exposure, like mesalamine, might increase the chance of birth defects in a pregnancy. Several studies of pregnant women who took mesalamine in the first trimester have not found an increased chance of birth defects.
One study looked at the medical records of more than 2,000 infants who were reported to have been exposed to mesalamine during the first trimester of pregnancy. The study found a small increase in the chance of heart defects. However, many of the women in the study were also taking other medications. Because of this, it is hard to know whether the slightly higher rate of heart defects was due to mesalamine, a combination of medications, the underlying medical condition, or other factors.
Does taking mesalamine in pregnancy increase the chance of other pregnancy-related problems?
Mesalamine is not expected to increase the chance of pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth).
Does taking mesalamine in pregnancy affect future behavior or learning for the child?
Studies have not been done to see if mesalamine can increase the chance of behavior or learning issues in children.
Breastfeeding while taking mesalamine:
Mesalamine passes into breast milk in small amounts. Most babies have not experienced any side effects. Some babies have developed diarrhea after exposure to mesalamine in breast milk. If you are taking mesalamine while breastfeeding, monitor your baby closely for any changes in bowel movements. If you suspect your baby has symptoms (such as diarrhea), contact the child’s healthcare provider. Be sure to talk to your healthcare provider about all your breastfeeding questions.
If a man takes mesalamine, could it affect fertility or increase the chance of birth defects?
There have been some reports of men who had lower sperm counts while taking mesalamine. Sperm counts returned to previous levels after stopping the medication. Low sperm counts can affect the ability to conceive a pregnancy. There are no studies looking at the possible risks to a pregnancy when a man takes mesalamine. In general, exposures that fathers or sperm donors have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet on Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/.
Please click here for references.
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 https://mothertobaby.org/join-study/.
