Crude and adjusted ORs, with 95% CI, for adverse birth outcomes in the study cohorts of children after assisted reproductive technology (ART) in women with UC compared with children after ART in women without IBD; similar results in women with CD (1 January 1994 through 2013)
| UC | ||||
|---|---|---|---|---|
| Exposed cohort* (embryo transfers in women with UC) | Unexposed cohort† (embryo transfers in women without IBD) | Crude OR (95% CI) | Adjusted OR‡ (95% CI) | |
| Preterm birth§ | ||||
| Yes, N (%) | 100 (30.77) | 9708 (23.00) | 3.53 (1.72 to 7.22) | 5.29 (2.41 to 11.63) |
| No, N (%) | 225 (69.23) | 32 493 (77.00) | ||
| LBW at term¶ | ||||
| Yes, N (%) | 13 (5.75) | 1802 (5.55) | 1.07 (0.49 to 2.30) | 1.48 (0.69 to 3.13)** |
| No, N (%) | 213 (94.25) | 30 684 (94.45) | ||
| Congenital abnormalities | ||||
| Yes, N (%) | 61 (18.83) | 6652 (15.73) | 1.29 (0.77 to 2.17) | 1.52 (0.87 to 2.64)** |
| No, N (%) | 263 (81.17) | 35 643 (84.27) | ||
| CD | ||||
| Exposed cohort†† (embryo transfers in women with CD) | Unexposed cohort†(embryo transfers in women without IBD) | Crude OR (95% CI) | Adjusted OR‡ (95% CI) | |
| Preterm birth§ | ||||
| Yes, N (%) | 18 (16.98) | 9708 (23.00) | 0.42 (0.09 to 1.93) | 0.44 (0.09 to 2.21) |
| No, N (%) | 88 (83.02) | 32 493 (77.00) | ||
| LBW at term¶ | ||||
| Yes, N (%) | 5 (5.62) | 1802 (5.55) | 0.99 (0.28 to 3.49) | 1.41 (0.40 to 4.89)** |
| No, N (%) | 84 (94.38) | 30 684 (94.45) | ||
| Congenital abnormalities | ||||
| Yes, N (%) | 13 (12.15) | 6652 (15.73) | 0.70 (0.27 to 1.84) | 0.59 (0.19 to 1.79)** |
| No, N (%) | 94 (87.85) | 35 643 (84.27) | ||
Intraclass correlation coefficient (ICC): preterm ICC=0.82; LBW ICC=0.54; CA ICC=0.62.
*Number of observations (women): preterm-UC: 325 (231); LBW-UC: 226 (177); CA-UC: 324 (230).
†Number of observations (women): preterm-non-IBD: 42 201 (29 898); LBW-non-IBD: 32 486 (24 918); CA-non-IBD: 42 295 (29 968).
‡Adjusted for women's age, parity, type of treatment (IVF, ICSI, FER), calendar year of treatment, cause of infertility (female factor, male factor, or mixture of factors/idiopathic) and smoking during pregnancy.
§Birth before 37 completed weeks of pregnancy.
¶Birth weight <2500 g in children born at gestational age ≥37 weeks.
**Also adjusted for singleton birth/multiple births.
††Number of observations (women): Preterm-CD: 106 (78); LBW-CD: 89 (68); CA-UC: 107 (79).
CA, congenital anomaly; CD, Crohn's disease; FER, frozen-thawed embryos; IBD, inflammatory bowel disease; ICSI, intracytoplasmic sperm injection; IVF, in vitro fertilisation; LBW, low birth weight; UC, ulcerative colitis.