Table 2 Odds ratios (ORs) of gastroschisis based on the pre-pregnancy body mass index (BMI)
Pre-pregnancy BMI | No. of women | No. of gastroschisis cases | Frequency of gastroschisis | Maternal age at delivery adjusted OR | 95% confidence interval |
|---|---|---|---|---|---|
Complete case analysis | |||||
< 18.5 kg/m2 (underweight) | 15,034 | 2 | 0.01 | 2.2 | (0.4–11.0) |
18.5–24.9 kg/m2 (reference) | 67,774 | 4 | 0.01 | Reference | |
≥ 25.0 kg/m2 (overweight) | 9864 | 2 | 0.02 | 3.4 | (0.6–17.8) |
(Situation 1) we categorised one mothera, who delivered an infant with gastroschisis and had no information on height and weight before pregnancy, as in the reference group | |||||
< 18.5 kg/m2 (underweight) | 15,034 | 2 | 0.01 | 1.7 | (0.4–8.3) |
18.5–24.9 kg/m2 (reference) | 67,775 | 5 | 0.01 | Reference | |
≥ 25.0 kg/m2 (overweight) | 9864 | 2 | 0.02 | 2.7 | (0.5–13.5) |
(Situation 2) we categorised one mothera, who delivered an infant with gastroschisis and had no information on height and weight before pregnancy, as in the underweight group. | |||||
< 18.5 kg/m2 (underweight) | 15,035 | 3 | 0.01 | 3.1 | (0.7–13.6) |
18.5–24.9 kg/m2 (reference) | 67,774 | 4 | 0.01 | Reference | |
≥ 25.0 kg/m2 (overweight) | 9864 | 2 | 0.02 | 3.5 | (0.7–18.2) |
(Situation 3) given situation 1, we re-categorised two cases of women with BMI < 18.5 kg/m2 as women of the reference group, because their BMI values were near 18.5 kg/m2 | |||||
< 18.5 kg/m2 (underweight) | 15,032 | 0 | 0 | ||
18.5–24.9 kg/m2 (reference) | 67,777 | 7 | 0.01 | Reference | |
≥ 25.0 kg/m2 (overweight) | 9864 | 2 | 0.02 | 2.0 | (0.4–9.8) |