Fertility and IBD Part 2

Crohn’s Disease and Ulcerative Colitis (the two main forms of Inflammatory Bowel Disease – IBD) are often first diagnosed in people in their 20s and 30s. This is also the age at which many couples are thinking of having children. If you or your partner have IBD and are thinking of starting a family, you may be concerned about how IBD might affect your fertility. This series of articles look at the main ways in which UC or Crohn’s, or the treatments for these conditions, may sometimes have an effect on fertility


How do IBD drug treatments affect fertility?

The majority of drug treatments for IBD do not affect fertility and are also safe in pregnancy.

However, there are some exceptions, as shown below. If you are trying to start a family, or if you are already pregnant, do discuss this and your drug treatment with your doctor or IBD team. It is better to avoid flare ups while trying to conceive and while pregnant, so most doctors will recommend continuing with your medication unless there are clear reasons not to. If the drugs you are on are not thought to be completely safe, there is usually a good alternative. 

For more information on the drugs mentioned below, see our individual drug treatment leaflets and our booklet Drugs and IBD. 


Specific drug treatments that may affect fertility or conception:

Sulphasalazine (Salazopyrin), a 5-ASA medication commonly used for IBD, is known to reduce fertility in men. This effect is usually temporary however, and fertility should return to normal levels within two to three months of stopping the medication. One study has also suggested that there may be an increased risk of birth defects if the father has been taking sulphasalazine. There are several good alternatives to sulphasalazine, such as mesalazine, olsalazine or balsalazide, which can usually be used instead. These have the same action 
on the colon but do not affect fertility. Sulphasalazine has not been shown to affect fertility in women or to be linked to any birth defects if taken by women. 

Methotrexate, an immunosuppressive drug sometimes prescribed for IBD, can increase the risk of birth defects if taken by women at conception or during pregnancy. It may also affect sperm production and quality. So it should not be taken by either partner when trying to conceive a child. Traces of methotrexate can remain in the body tissues for some time and couples are usually advised to avoid pregnancy for at least 6 months after stopping methotrexate. 

Mycophenolate Mofetil, another immunosuppressant, may cause miscarriages or birth defects if used during pregnancy. Women being treated with this drug will be advised to stop taking it at least 6 weeks before conception. 


The immunosuppressive drugs azathioprine and mercaptopurine (6MP) have not been shown to affect fertility, but one study has suggested that conceiving a child with a man taking these drugs may carry an increased risk of miscarriage or birth defects. Because of this, some doctors have advised men planning to father a child to switch to other medication. 

More recent research has not replicated these findings and many doctors now advise continuing with azathioprine or mercaptopurine, rather than risking a flare-up of the IBD. Similar advice is usually now given to women taking azathioprine or mercaptopurine. Although some doctors may still recommend caution with the use of these drugs during pregnancy, there are growing numbers of women who have had successful births while taking these immunosuppressants. 

Infliximab (Remicade) and adalimumab (Humira) are relatively new drugs, known as ‘biologics’ or ‘antiTNF drugs’. These affect the immune process and are used in severe cases of Crohn’s Disease and sometimes UC, when other drugs have not worked. Research is ongoing into the effect of infliximab and adalimumab on fertility and pregnancy. Several studies have found that women taking infliximab during pregnancy had the same birth outcome as for the general population of pregnant women, or women with IBD who had not been taking infliximab. 

There have also been reports of successful pregnancies in women with Crohn’s who began adalimumab before conception or during pregnancy. However, evidence is still limited about the long term effects on the baby if the mother takes anti-TNF drugs while pregnant. Recent guidelines suggest that doctors should talk through the possible risks and benefits of taking infliximab or adalimumab when pregnant, on an individual basis. They also recommend stopping anti-TNF medication at the end of the second  trimester, when the woman is six months pregnant. If you do decide to stop anti-TNF medication before 
conception, you will need to wait at least 6 months after the last treatment to be certain the drug has left your 
system.

In part 3: Can you improve fertility?