Crohn’s Disease (CD), a chronic inflammatory bowel disease (IBD), frequently affects women during their prime reproductive years. While CD can influence pregnancy outcomes, the vast majority of women who receive proper medical care successfully carry their pregnancies to term and deliver healthy babies. Pregnancy success is most strongly tied to managing the disease state before and during gestation.
The Critical Role of Disease Activity
The single most important factor determining a successful pregnancy outcome for a woman with Crohn’s disease is whether the disease is in remission at the time of conception. Women whose CD is inactive have fertility rates comparable to women without the condition. Active inflammation or previous extensive surgery, such as a colectomy with a J-pouch, may lower fertility.
Active Crohn’s disease at conception significantly raises the risk of adverse maternal and fetal outcomes. When conception occurs during a flare-up, the disease is more likely to remain active or worsen, increasing the chances of complications for the developing baby.
Inflammation due to active disease is associated with a higher risk of spontaneous abortion, preterm delivery, and having a baby with a low birth weight. Achieving and maintaining remission, ideally for three to six months prior to conception, is the primary goal to mitigate these risks. Maintaining this inactive state throughout all three trimesters is equally important, as a flare during pregnancy can lead to poor outcomes.
Managing Crohn’s Medications During Pregnancy
A common concern among women is the safety of their maintenance medications during pregnancy, which sometimes leads to the discontinuation of effective treatment. Stopping medication is generally more dangerous than continuing it, because the risks posed by active disease far outweigh the potential risks of most CD drugs. Discontinuation frequently results in a flare, which directly endangers the pregnancy.
Most medications used to treat Crohn’s disease are considered safe to continue throughout gestation. Aminosalicylates (like mesalamine) and thiopurines (like azathioprine) are generally safe for use. Corticosteroids may also be used safely to treat acute flares during pregnancy.
Biologics, including anti-tumor necrosis factor (TNF) agents, also have reassuring safety data. Certolizumab pegol is often considered one of the safest biologics because it undergoes minimal transfer across the placenta. Other biologics, such as infliximab and adalimumab, cross the placenta more readily in the third trimester, but they are generally continued to maintain remission, with dosing adjustments sometimes considered later in pregnancy.
One notable exception is methotrexate, which is strictly contraindicated due to its teratogenic effects. It must be discontinued several months before attempting to conceive. Patients taking sulfasalazine or thiopurines should ensure they are taking high-dose folic acid supplements. Folic acid is important in pregnancy and counteracts potential drug interference with folate metabolism.
Delivery Planning and Perianal Disease
For the majority of women with Crohn’s disease, a vaginal delivery is a safe option. CD limited to the small intestine or colon without perianal involvement does not typically require a planned Cesarean section (C-section). The decision on the mode of delivery should be a joint choice between the patient, her gastroenterologist, and the obstetric team.
A C-section is usually recommended when CD involves active or severe perianal disease. This includes women with active perianal fistulas, abscesses, or significant inflammation in the rectum and anal area at the time of delivery. Vaginal delivery in these circumstances carries a risk of trauma to the perineal tissues and could potentially worsen the existing perianal disease or impair sphincter function.
Although research comparing delivery methods has shown similar rates of perianal flare regardless of the delivery mode, a C-section is often chosen to avoid the mechanical pressure of labor and potential tearing of the perineum in women with high-risk perianal involvement. Women with CD have a slightly increased risk of a disease flare in the postpartum period.