From one-quarter to half of patients with inflammatory bowel disease (IBD) are below 35 years of age when diagnosed, or will become pregnant after they receive this diagnosis. The single most important principle of managing IBD during pregnancy is the paramount need to control the disease during the period of conception and throughout pregnancy.
An optimum regimen must be worked out to achieve the best outcome for both mother and fetus. Thus the first condition is that a woman known to have IBD should try to conceive when she is in a period of quiescent disease. This situation is linked to a lower risk of spontaneous abortion, complications related to pregnancy, and poor neonatal outcomes, comparable to that of the general population.
Effect of IBD on Pregnancy
When IBD is active before and during pregnancy, several complications are more likely to occur, such as:
- Miscarriage rates of up to 35%
- Preterm labor and premature birth (though usually after 35 weeks)
- Low birth weight
- Infants who are small for gestational age
- Higher risk of Caesarean delivery, perhaps due to the possibility of perianal disease, fistulas, or enterostomies
- Risk of venous thromboembolic disease
- Risk of protein-calorie malnutrition
- Need for blood transfusion during delivery
The risk of fetal malformations has not been associated with IBD per se. Smoking increases the risk for preterm labor in women who have Crohn’s disease, but not in those with ulcerative colitis.
Effect of Pregnancy on IBD
When pregnancy begins with the disease in an active phase, one-third of women will improve, one-third will remain the same, while another third will experience worsening symptoms. Some workers hypothesize that the presence of the fetal immune system, which is different from the mother’s, has a beneficial effect on the latter’s immune activity.
IBD flares are not more common in pregnancy, so the latter does not obviously have any long-term effect on IBD. Women with ulcerative colitis (UC) tend to remain quiescent (70-80%) if conception occurred in such a phase. This may be related to cessation of medications or if smoking is carried out during pregnancy. However, if a woman with active UC conceives, the condition is more difficult to treat.
Women with Crohn’s disease react to pregnancy in almost the same way as those with UC.
Elective termination simply on the ground of having IBD is not acceptable because of the low overall risk of any complications due solely to the disease.
IBD and the Postpartum Period
Inflammatory bowel disease by itself is not a contraindication to breastfeeding, but the presence of antimetabolites or antibodies in the mother’s blood may require cessation of nursing.
Drugs During Pregnancy with IBD
It is universally agreed that it is far more dangerous to have active disease during pregnancy than to have active treatment with therapeutic agents. Drugs that may be continued during pregnancy include the aminosalicylates, the antibiotics such as ampicillin, erythromycin, ciprofloxacin and metronidazole, biologics such as anti-TNF-α, and certain immunomodulators.
These drugs are considered safe in pregnancy. Women on sulfasalazine should receive folic acid supplementation to minimize neural tube defects.
These include azathioprine and methotrexate. Methotrexate is a known teratogen and should be avoided during pregnancy, but azathioprine and 6-mercaptopurine can be continued as no difference in women on and not on these medications has been documented.
These agents are used for very active IBD, though sometimes they are used as a first option. Anti-TNF-α drugs include infliximab, adalimumab, natalizumab, while other drugs used include anti-integrin molecules. Current recommendations are to continue the use of biologics at least until 30 weeks of gestation. They have not been shown to cause any negative outcomes in the short term, despite the occurrence of placental transfer, since this happens only after the 20th week, and does not affect organogenesis. However, long-term outcomes are yet to be determined for this relatively new modality.
Moreover, the use of biologics does not produce pregnancy complications in excess but instead decreases neonatal complications because of more efficient induction of remission of disease.
However, it is important to ensure that newborns do not receive immunization until the age of at least 12 months to avoid disseminated infection due to their immunosuppressed status. At the same time, it is essential to be alert to the possibility of infections in the infant without any of the clinical signs usually expected and to initiate investigations or treatment earlier in such cases.
These powerful anti-inflammatory drugs are used to control disease activity when required even during pregnancy, without a significant risk of fetal anomalies.
Procedures for IBD in pregnancy
Some indications for endoscopy may occur during pregnancy, such as gastrointestinal bleeding, dysphagia, nausea or vomiting which does not respond to treatment, or if a colonic mass is suspected. Since endoscopy is not known to pose a threat to pregnancy, it should be carried out as indicated, with proper obstetrical support.
Reviewed by Yolanda Smith, BPharm