Women with inflammatory bowel disease (IBD) who underwent embryo transfer had higher pregnancy success rates than those who underwent intrauterine insemination (IUI), according to prospective findings presented at the American College of Gastroenterology’s 2026 Annual Scientific Meeting in Nashville, Tennessee.
Eugenia Shmidt, MD, of the University of Minnesota, presented the findings from the multicenter Women with Inflammatory Bowel Disease and Motherhood (WIsDoM) cohort during an oral abstract session.
Dr. Shmidt explained that some women with IBD may experience reduced fertility, particularly during periods of active disease or following pelvic surgery requiring rectal dissection. Citing a 2025 global consensus statement, she noted that assisted reproductive technology (ART) effectiveness appears comparable in women with and without IBD and that in vitro fertilization (IVF) may overcome infertility associated with IBD-related pelvic surgery. Knowledge gaps remain, however. “Specifically, we lack prospective data on how fertility treatments are utilized in real-world clinical practice and what key clinical factors such as surgical history predict pregnancy success,” Dr. Shmidt said during her presentation.
To address these gaps, Dr. Shmidt said the study had two main aims. “First, we sought to prospectively characterize fertility treatment utilization and success in women with IBD enrolled in the WIsDoM cohort, specifically determining whether or not women achieved pregnancy and tracking outcomes through 12 weeks of gestation, including early pregnancy loss. Second, we aimed to identify key clinical, demographic, surgical, and treatment-related factors associated with fertility treatment outcomes.”
Study design and population
Investigators analyzed data from WIsDoM, a prospective observational registry launched in 2021 involving more than 30 sites across the United States and Canada. The cohort included 421 biologically female patients with IBD aged 18 to 45 who were planning to become pregnant within 15 months. Participants completed baseline questionnaires at enrollment and monthly thereafter via a digital platform. Questionnaire data were adjudicated through medical record review. Key data elements included age, prior fertility treatment, disease activity, and IBD-related surgery. The investigators prospectively captured fertility treatment modality utilization, pregnancy success, and outcomes through 12 weeks of gestation.
Of the 421 participants, 67 underwent at least one fertility treatment during follow-up: 52 who attempted pregnancy through IUI or embryo transfer, and 15 who underwent egg retrieval without subsequent transfer.
Women who underwent fertility treatment were older than those who did not (median age, 34 vs. 32 years; P<0.001), spent longer attempting conception (median, 11 vs. 2 months; P<0.001), and were about three times as likely to have a history of pelvic IBD surgery (16.4% vs. 5.4%; P=0.01). Prior fertility treatment was also more common among women receiving treatment (31.3% vs. 8.8%; P<0.001).
“Notably, women undergoing fertility treatment showed a non-statistically significant trend toward more reported active disease within three months prior to the first fertility treatment,” Dr. Shmidt said.
Active disease was reported in 56.7% of women receiving fertility treatment, compared with 43.5% of those not receiving treatment, whose disease activity was assessed at enrollment (P=0.06).
Investigators recorded 148 fertility treatment events across the cohort: 51 egg retrievals, 49 IUI attempts, and 48 embryo transfers. The IUI attempts and embryo transfers constituted 97 pregnancy attempts among 52 women.
Repeat treatment attempts were common, with 22 of the 52 women (42%) undergoing multiple attempts. Women undergoing IUI averaged 2.45 attempts, compared with 1.23 attempts among those undergoing embryo transfer.
Thirty-two women proceeded directly to embryo transfer without prior IUI during the study, while seven progressed from IUI to embryo transfer after an average of about three IUI attempts.
The primary outcome was pregnancy success following fertility treatment, and secondary outcomes included baseline cohort comparisons and multivariable predictors of success.
“Our statistical approach evaluated pregnancy success at both the patient level and the per treatment attempt level, given one patient may have had multiple pregnancy attempts during the study period,” Dr. Shmidt said.
The attempt-level multivariable model adjusted for disease activity, IBD-related surgery, prior ART use, disease duration, and attempt number, and accounted for repeated attempts within individual patients.
The data were presented as an abstract and have not been published in a peer-reviewed journal.
Pregnancy outcomes
Overall, 38 of 52 women (73%) achieved pregnancy with at least one fertility modality. However, success varied by modality. Among women undergoing IUI only, five of 13 (38%) achieved pregnancy. In contrast, 33 of 39 women (85%) undergoing embryo transfer with or without prior IUI achieved pregnancy.
Among the five women who achieved pregnancy in the IUI-only group, two experienced early pregnancy loss. Among the 33 women who achieved pregnancy in the embryo transfer group, seven experienced early pregnancy loss and one had a molar pregnancy.
Among the nine women with prior IBD-related pelvic surgery, all seven who underwent embryo transfer, with or without prior IUI, conceived (100%), compared with neither of the two women who underwent IUI alone (0%).
At the attempt level, 40 of 97 attempts (41%) resulted in pregnancy. IUI resulted in pregnancy in five of 49 attempts (10%), and embryo transfer resulted in pregnancy in 35 of 48 attempts (73%).
In unadjusted analysis, embryo transfer was associated with 24-fold higher odds of pregnancy per attempt compared with IUI (odds ratio [OR], 24; 95% CI, 8.0–70; P<0.0001).
After adjustment for potential confounders, embryo transfer remained associated with higher odds of pregnancy (adjusted OR, 44; 95% CI, 8.9–221; P<0.0001).
The investigators also examined outcomes at the individual patient level. In a separate multivariable analysis, embryo transfer with or without prior IUI was associated with higher odds of pregnancy compared with IUI alone (OR, 9.1; 95% CI, 2.1–47.7; P=0.005).
Embryo transfer was associated with higher odds of pregnancy than IUI whether or not women had undergone prior IUI. The adjusted odds ratio favoring embryo transfer was 53 (95% CI, 6.4–443; P=0.0002) among women without prior IUI and 14 (95% CI, 2.3–92; P=0.004) among those with prior IUI.
The researchers also evaluated whether prior IUI cycles affected subsequent embryo transfer success. Prior IUI was not associated with embryo transfer success (70% with vs. 73% without prior IUI; OR, 0.83; 95% CI, 0.17–4.1; P=0.82). “This suggests that prior failure of IUI does not impair subsequent embryo transfer effectiveness,” Dr. Shmidt said.
In the attempt-level adjusted analysis, other evaluated factors, including disease activity and surgical history, were not significantly associated with pregnancy success. Dr. Shmidt suggested that this finding may indicate that embryo transfer “effectively overcomes disease- and surgery-related factors.”
Clinical implications and future research
“Modality selection is paramount,” Dr. Shmidt said, suggesting that clinicians should consider early referral to IVF and embryo transfer rather than prolonged IUI attempts in women with IBD, particularly those with prior pelvic surgery.
During the question-and-answer session, Dr. Shmidt compared the study’s success rates with those in the general population. “So from an IUI standpoint, our IUI rates were 10% in the attempt level and embryo transfer was 73% effective. Compared to that of the general population — in the general population, the effectiveness is about 10% to 15% for IUI and 45% to 50% for embryo transfer. So as you can tell, our embryo transfer success rate was higher than that of the general population.”
Dr. Shmidt suggested that women with IBD may particularly benefit from embryo transfer because she believes pelvic adhesions and tubal factor infertility are major contributors to infertility in this population.
“So that is why I think women with IBD not only are comparable in terms of effectiveness for fertility treatment, but I think that they benefit from fertility treatments even more than that of the general population,” she said. “And to investigate that further, we are actually working to obtain hysterosalpingogram data in order to do a deeper dive into that theory and our outcomes.”
In response to a question about live birth outcomes, Dr. Shmidt clarified that the study focused on clinical pregnancy through 12 weeks of gestation, including early pregnancy loss. Live birth outcomes were not reported.
The study was supported by the Leona M. and Harry B. Helmsley Charitable Trust. Investigator disclosures were not provided.