Older studies have estimated infertility rates between 32 and 42 % in women with CD but more recent reviews indicated infertility rates closer to 5 and 14 % which is similar to the general population [1–4]. When looking at population and referral center-based studies, the majority of studies have found involuntary infertility in IBD patients to be similar to the general population [5]. It is felt that fertility in a CD patient in remission is equivalent to a healthy woman but may be decreased with active inflammation with subfertility seen in CD patients with active disease [6, 7]. Overall, most studies have not seen a decrease in fertility in UC women when compared to the general population except with surgical resection and ileal pouch-anal anastomosis (IPAA) [5, 8, 9]. In quiescent disease, male and female fertility is not significantly affected in the nonoperated IBD patient [10].

IPAA can increase the risk of subfertility in women by approximately threefold [11]. When defining infertility as the inability to achieve pregnancy within 12 months, the rates increase from 15 to 48 % in women post IPAA for UC [9, 11–14]. It is important to remember that the IPAA may result in a mechanical infertility (tubal factor) in these patients and there is a reduced probability of conception rather than a true infertility [13]. More recently, pregnancy rates have been shown to be significantly higher after laparoscopic IPAA and that in vitro pregnancy outcomes and success rates after IPAA are similar to the general population [12].

IBD medications do not negatively impact fertility except for sulfasalazine and MTX. Sulfasalazine in men can induce oligospermia, decreased sperm motility, and abnormal morphology which cause a reversible infertility [15–17]. Sperm quality is restored within 2 months or two full cycles of spermatogenesis after drug cessation or switching to another 5-ASA agent [7, 10].

Methotrexate has been reported to cause reversible oligospermia and has known teratogenic properties [18]. Despite the fact that no increase in congenital abnormalities in children conceived by fathers on MTX has been reported, it is still recommended to wait at least 3–6 months prior to conception. MTX does not affect a female’s ability to achieve pregnancy; however, due to adverse fetal effects and early pregnancy loss, discontinuation is recommended 6 months prior to conception.