Table 1. Characteristics of the isotretinoin exposure and non-exposure groups.
| Characteristics | Exposure | Non-exposure | P-valuea) | ||
|---|---|---|---|---|---|
| Pregnancies (n=22,374) | 650 (2.9) | 21,724 (97.1) | |||
| Maternal age (yr) | |||||
| Mean±SD | 29.0±4.4 | 32.0±4.2 | <0.001 | ||
| Range | 18.1–46.0 | 15.2–51.3 | |||
| No. of subjects by ages (%) | |||||
| <20 | 4 (0.7) | 16 (0.1) | <0.001 | ||
| ≥20–24 | 65 (11.9) | 575 (3.1) | |||
| ≥25–29 | 246 (45.1) | 3,876 (21.1) | |||
| ≥30–34 | 171 (31.1) | 8,944 (48.7) | |||
| ≥35 | 60 (11.0) | 4,954 (27.0) | |||
| Gravidity | 1.1±0.9 | 1.4±1.1 | <0.001 | ||
| Parity | 0.2±0.5 | 0.4±0.6 | <0.001 | ||
| Spontaneous abortion | 0.03±0.17 | 0.07±0.32 | 0.001 | ||
| Therapeutic abortion | 0.12±0.50 | 0.11±0.44 | 0.443 | ||
| Duration of isotretinoin exposure (day), median (range) | 18 (1–4,231) | - | |||
| Alcohol | |||||
| No | 543 (83.5) | 18,686 (86.0) | 0.073 | ||
| Yes | 107 (16.5) | 3,038 (14.0) | |||
| Cigarette smoking | |||||
| No | 622 (95.7) | 21,052 (96.9) | 0.080 | ||
| Yes | 28 (4.3) | 672 (3.1) | |||
Values are presented as number (%) or mean±standard deviation.
SD, standard deviation.
a)P<0.05, t-test or χ2 test.