Table 3. Maternal inter-pregnancy weight change and risk of low Apgar score (0–6) at 5 min, neonatal seizures, and meconium aspiration, stratified by maternal BMI in first pregnancy: live singleton second term infants of women in Sweden 1992–2012.
| Outcome | Inter-pregnancy Weight Change (kg/m2) | Maternal BMI < 25 kg/m2 | Maternal BMI ≥ 25 kg/m2 | Interaction p-Value | ||
|---|---|---|---|---|---|---|
| Number with Outcome (Rate/1,000) | OR (95% CI) | Number with Outcome (Rate/1,000) | OR (95% CI) | |||
| Low Apgar score (0–6) | Total | 1,361 (4.45) | 811 (7.06) | 0.12 | ||
| <−2 | 24 (3.47) | 0.82 (0.54–1.26) | 72 (5.84) | 0.83 (0.63–1.09) | ||
| −2 to <−1 | 81 (3.34) | 0.83 (0.66–1.05) | 74 (6.44) | 0.98 (0.75–1.27) | ||
| −1 to <1 | 633 (4.08) | 1.00 | 245 (6.43) | 1.00 | ||
| 1 to <2 | 314 (4.88) | 1.16 (1.01–1.33) | 144 (7.10) | 1.10 (0.89–1.35) | ||
| 2 to <4 | 225 (5.33) | 1.24 (1.06–1.46) | 182 (8.37) | 1.26 (1.04–1.53) | ||
| ≥4 | 84 (6.63) | 1.50 (1.18–1.92) | 94 (8.59) | 1.20 (0.94–1.55) | ||
| Neonatal seizures | Total | 322 (1.10) | 196 (1.70) | 0.004 | ||
| <−2 | 5 (0.71) | 0.65 (0.24–1.77) | 25 (1.98) | 1.25 (0.78–2.01) | ||
| −2 to <−1 | 19 (0.77) | 0.87 (0.54–1.41) | 20 (1.69) | 1.12 (0.67–1.86) | ||
| −1 to <1 | 142 (0.90) | 1.00 | 61 (1.57) | 1.00 | ||
| 1 to <2 | 73 (1.11) | 1.21 (0.91–1.61) | 32 (1.54) | 1.00 (0.65–1.54) | ||
| 2 to <4 | 65 (1.51) | 1.65 (1.22–2.24) | 43 (1.93) | 1.21 (0.81–1.81) | ||
| ≥4 | 24 (1.85) | 2.04 (1.30–3.22) | 20 (1.79) | 0.99 (0.57–1.70) | ||
| Meconium aspiration | Total | 181 (0.60) | 99 (0.90) | 0.77 | ||
| <−2 | 2 (0.28) | 0.25 (0.03–1.78) | 8 (0.63) | 0.65 (0.28–1.49) | ||
| −2 to <−1 | 11 (0.44) | 0.81 (0.43–1.52) | 8 (0.68) | 0.90 (0.41–1.96) | ||
| −1 to <1 | 88 (0.56) | 1.00 | 29 (0.74) | 1.00 | ||
| 1 to <2 | 28 (0.43) | 0.74 (0.48–1.13) | 23 (1.10) | 1.46 (0.85–2.53) | ||
| 2 to <4 | 36 (0.84) | 1.27 (0.84–1.92) | 18 (0.81) | 0.96 (0.52–1.75) | ||
| ≥4 | 23 (1.77) | 2.22 (1.32–3.73) | 15 (1.34) | 1.46 (0.76–2.80) | ||
ORs were adjusted for BMI in first pregnancy, smoking in second pregnancy, maternal age at second birth, inter-pregnancy interval, mother’s education, mother’s country of birth, and year of second birth. Among mothers with BMI < 25 kg/m2, the adjusted analyses of low Apgar score include 300,002 second births with complete information on covariates; 1,334 infants had a low Apgar score. Among mothers with BMI ≥ 25 kg/m2, the corresponding numbers are 112,936 second births and 794 infants with low Apgar score. Among mothers with BMI < 25 kg/m2, the adjusted analyses of neonatal seizures include 305,670 second births with complete covariate information; 322 infant had neonatal seizures. Among mothers with BMI ≥ 25 kg/m2, the corresponding numbers are 115,580 second births and 196 infants with neonatal seizures. Among mothers with BMI < 25 kg/m2, the adjusted analyses of meconium aspiration include 305,653 second births with complete covariate information; 181 infants had meconium aspiration. Among mothers with BMI ≥ 25 kg/m2, the corresponding numbers are 115,553 second births and 99 infants with meconium aspiration.