Table 1.
Description of the study population
| Isotretinoin exposed* | Isotretinoin unexposed | P Value | |
|---|---|---|---|
| Pregnancies (N=203 962) | 51 | 203 911 | |
| Mean (±SD) maternal age at conception in years (95% CI) | 29.1 (4.9) (27.8 to 30.5) | 30.3 (4.7) (30.3 to 30.3) | 0.56 |
| Mean (±SD) gestational age at delivery in weeks (95% CI) | 39 (25 days) (38 to 40) | 39, 3 days (19 days) (39, 3 days–39, 3 days) |
0.33 |
| Fetuses (N=208 161) | 53 | 208 108 | |
| Gender (boy %) | 47.2% (33.3–61.1) | 51.5% (51.3–51.7) | 0.53 |
| Maternal age at conception in years, N, column % | 0.37 | ||
| <20 | 2 (3.8%) | 4063 (2.0%) | |
| ≥20–25 | 7 (13.2%) | 22 144 (10.6%) | |
| ≥25–30 | 21 (39.6%) | 68 366 (32.9%) | |
| ≥30–35 | 14 (26.4%) | 81 581 (39.2%) | |
| ≥35 | 9 (17.0%) | 31 951 (15.4%) | |
| Gestational age at delivery in weeks, N, column % | 0.64 | ||
| <27 | 1 (1.9%) | 2198 (1.1%) | |
| 27–30 | 1 (1.9%) | 1167 (0.6%) | |
| 31–33 | 0 (0.0%) | 2008 (1.0%) | |
| 34–36 | 3 (5.7%) | 7126 (3.4%) | |
| 37–39 | 12 (22.6%) | 50 854 (24.4%) | |
| >39 | 36 (67.9%) | 144 755 (69.5%) | |
| Adverse fetal outcome, N; % (95% CI) | 5; 9.4% (1.3 to 17.6) |
9041; 4.3% (4.3 to 4.4) |
0.08 |
*In the 30 days before conception or during pregnancy.