Table 4.
Stratification analyses by smoking before pregnancy for the likelihood for total and recurrent spontaneous abortion (SA) by body mass index (BMI) at 18–20 years old in the Health Examinee Study (HEXA), 2004–2012
| BMI (kg/m2) | Smokers before pregnancy | Never-smokers before pregnancy | ||
|---|---|---|---|---|
| SA | OR1 (95% CI)1 | SA | OR1 (95% CI)1 | |
| N (%) | N (%) | |||
| <18.5 | 34 (26.0) | 1.31 (0.70–2.44) | 3,060 (17.5) | 1.09 (1.05–1.15) |
| 18.5–22.9 | 49 (67.1) | 1.00 (ref) | 12,249 (69.9) | 1.00 (ref) |
| 23–24.9 | 3 (4.1) | 0.70 (0.12–1.40) | 1,666 (9.5) | 0.94 (0.89–1.00) |
| ≥25 | 2 (2.7) | 0.74 (0.15–3.59) | 545 (3.1) | 1.05 (0.95–1.16) |
1Adjusted by age, education, smoking before pregnancy, drinking status and first pregnancy age