Crude and adjusted ORs, with 95% CI, for adverse birth outcomes in singletons after assisted reproductive technology (ART) in women with UC compared with singletons 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 (%) | 33 (15.14) | 2593 (9.20) | 1.61 (0.48 to 5.39) | 1.80 (0.49 to 6.62) |
| No, N (%) | 185 (84.86) | 25 589 (90.80) | ||
| LBW at term¶ | ||||
| Yes, N (%) | 3 (1.61) | 496 (1.94) | 0.81 (0.24 to 2.81) | 1.12 (0.32 to 3.98) |
| No, N (%) | 183 (98.39) | 25 122 (98.06) | ||
| Congenital abnormalities | ||||
| Yes, N (%) | 27 (12.44) | 3721 (13.16) | 0.94 (0.61 to 1.43) | 1.14 (0.74 to 1.76) |
| No, N (%) | 190 (87.56) | 24 547 (86.84) | ||
| 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 (%) | 8 (10.00) | 2593 (9.20) | 1.03 (0.10 to 10.30) | 0.83 (0.05 to 13.55) |
| No, N (%) | 72 (90.00) | 25 589 (90.80) | ||
| LBW at term¶ | ||||
| Yes, N (%) | 1 (1.37) | 496 (1.94) | 0.69 (0.08 to 5.75) | 0.91 (0.11 to 7.94) |
| No, N (%) | 72 (98.63) | 25 122 (98.06) | ||
| Congenital abnormalities | ||||
| Yes, N (%) | 10 (12.35) | 3721 (13.16) | 0.92 (0.46 to 1.84) | 0.72 (0.32 to 1.64) |
| No, N (%) | 71 (87.65) | 24 547 (86.84) | ||
Intraclass correlation coefficient (ICC): preterm ICC=0.99; LBW ICC=0.41; CA ICC=0.09.
*Number of observations (women): preterm-UC: 218 (187); LBW at term-UC: 186(160); CA-UC: 217 (186).
†Number of observations (women): preterm-non-IBD: 28 182 (24 169); LBW-non-IBD: 25 618 (22 142); CA-non-IBD: 28 268 (24 283).
‡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.
**Number of observations (women), Preterm-CD: 80 (70), LBW at term-CD: 73 (64), CA-CD: 81 (71).
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.