This sheet is about exposure to mesalamine in pregnancy and while breastfeeding. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.
What is mesalamine?
Mesalamine is an anti-inflammatory (reduces inflammation or swelling) medication. Mesalamine has been used to treat ulcerative colitis, an inflammatory bowel disease (IBD). It belongs to a class of medications called 5-aminosalicylic acid (5-ASA). Another name for mesalamine is mesalazine. Some brand names for mesalamine that can be taken orally are Apriso®, Asacol®, Delzicol®, Lialda® and Pentasa®. Some brand names for mesalamine that can be taken rectally are Canasa®, Rowasa® and Pentasa®.
Sometimes when people 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. Your healthcare providers can talk with you about the benefits of treating your condition and the risks of untreated illness during pregnancy. Untreated IBD increases the risk for complications for both the person who is pregnant and the fetus. 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?
It is not known 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 people who used mesalamine in the first trimester did not find a higher chance of miscarriage.
Does taking mesalamine increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Use of mesalamine in pregnancy is considered unlikely to significantly increase the chance of birth defects. There have been several studies looking at pregnancies exposed to both oral and rectal mesalamine in the first trimester that have found no increased chance of birth defects.
One study reviewed medical records of over 2,000 infants who were reportedly exposed to mesalamine at some time during the first trimester of pregnancy. This study found a slightly higher chance of heart defects. Many of the people in this study had also used other medications. This makes it hard to know if mesalamine, a combination of medications, the underlying disease, or other factors contributed to the reported slightly higher rate of heart defects.
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). There have been questions about a higher chance for preterm delivery and stillbirth from earlier reports. However, more recent data has not suggested an increased chance for these complications.
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 for the child.
Breastfeeding while taking mesalamine:
Mesalamine gets into breast milk in small amounts. Diarrhea has been reported in some breastfeeding infants. There have also been reports of breastfed infants who did not have side effects. If you take mesalamine while breastfeeding, the nursing infant should be watched closely for changes in bowel activity. If you suspect the baby has any 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 male takes mesalamine, could it affect fertility or increase the chance of birth defects?
There have been some reports of males who had lower sperm count while taking mesalamine. This could affect male fertility (ability to get partner pregnant). Sperm counts returned to usual after stopping the medication. There are no studies looking at possible risks to a pregnancy when the father or sperm donor 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/.
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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/.
OTIS/MotherToBaby encourages inclusive and person-centered language. While our name still contains a reference to mothers, we are updating our resources with more inclusive terms. Use of the term mother or maternal refers to a person who is pregnant. Use of the term father or paternal refers to a person who contributes sperm.
