Table 2.
Maternal interpregnancy BMI change and neonatal (birth to 28 ≤d) mortality of a subsequent child
| Full term (≥37 wk gestation) N = 247,940 | Preterm (<37 wk gestation) N = 18,812 | |||
|---|---|---|---|---|
| All-cause mortality | Hazard rate ratioa | 95% CI | Hazard rate ratioa | 95% CI |
| Weight change: | ||||
| Lost 1 kg/m2 or more | 1.46 | 1.04–2.05 | 1.05 | 0.83–1.32 |
| Lost 1 kg/m2 to no change | 1.14 | 0.79–1.65 | 1.17 | 0.93–1.47 |
| Gained 0 kg/m2 to <1 kg/m2 | 1.00 | 1.00 | ||
| Gained 1 to <2 kg/m2 | 1.11 | 0.77–1.62 | 0.83 | 0.64–1.07 |
| Gained 2 to <4 kg/m2 | 1.29 | 0.91–1.82 | 1.04 | 0.82–1.33 |
| Gained 4 kg/m2 or more | 1.72 | 1.23–2.41 | 0.97 | 0.75–1.25 |
| Trend | 1.04 | 0.97–1.11 | 0.97 | 0.93–1.02 |
| Mortality from congenital malformations | ||||
| Weight change: | ||||
| Lost 1 kg/m2 or more | 2.55 | 1.39–4.66 | 1.06 | 0.65–1.73 |
| Lost 1 kg/m2 to no change | 1.65 | 0.85–3.20 | 1.00 | 0.60–1.66 |
| Gained 0 kg/m2 to <1 kg/m2 | 1.00 | 1.00 | ||
| Gained 1 to <2 kg/m2 | 1.20 | 0.57–2.53 | 0.98 | 0.58–1.63 |
| Gained 2 to <4 kg/m2 | 1.70 | 0.88–3.29 | 0.69 | 0.39–1.23 |
| Gained 4 kg/m2 or more | 2.30 | 1.19–4.45 | 0.67 | 0.36–1.23 |
| Trend | 0.98 | 0.86–1.11 | 0.91 | 0.82–1.02 |
Abbreviation: kg/m2, kilogram/meter squared.
a
These models control for whether the neonate was small-for-gestational age, large-for-gestational age, gestational age at delivery (weeks), neonatal sex, interpregnancy interval, assisted reproduction, and maternal race/ethnicity, age, education, marital status, smoking, diabetes, and hypertension during the subsequent pregnancy.