Table 2.
Characteristics of the new-borns and frequency of outcomes with respect to pre-pregnancy BMI.
| BMI categories | Total* | ||||
|---|---|---|---|---|---|
| Underweight | Normal | Overweight | Obesity | ||
| New-born characteristics& | |||||
| Gestational week (M ± SD, week) | 39.0 ± 1.4 | 39.0 ± 1.4 | 39.0 ± 1.5 | 39.0 ± 1.5 | 39.0 ± 1.4 |
| Birth weight (M ± SD, week) | 3142 ± 136 | 3187 ± 385 | 3214 ± 394 | 3224 ± 412 | 3181 ± 384 |
| Male sex (n, %) | 70,523(51.8) | 235,450(52.5) | 37,232(53.3) | 7621(52.4) | 350,826(52.4) |
| New-born outcomes& | |||||
| Preterm birth | 7133(5.2) | 22,240(5.0) | 3533(5.1) | 828(5.7) | 33,734(5.0) |
| Large for gestational age (n, %) ┼ | 12,544(9.2) | 52,581(11.7) | 9783(14.0) | 2296(15.8) | 77,204(11.5) |
| Small for gestational age (n, %)╪ | 16,266(11.9) | 41,711(9.3) | 5664(8.1) | 1141(7.8) | 64,782(9.7) |
| Stillbirth (n, %) ¶ | 50(0.9) | 206(1.2) | 38(1.8) | 10(2.2) | 304(1.2) |
| Obstetrical outcomes (N, %) Ϯ | |||||
| Caesarean delivery | |||||
| Primary | 18,742(13.8) | 65,454(14.6) | 10,264(14.7) | 2514(17.3) | 96,974(14.5) |
| Repeat | 5125(3.8) | 33,969(7.6) | 10,471(15.0) | 2588(17.8) | 52,153(7.8) |
| Shoulder dystocia or birth injury | 1567(1.2) | 5199(1.2) | 679(1.0) | 165(1.1) | 7610(1.1) |
┼Birth weight above the 90th percentile for gestational age by infants’ sex;
╪Birth weight below the 10th percentile for gestational age by infants’ sex;
&Total number of participants is 669,101;
¶Total number of participants is 256,882;
ϮTotal number of participants is 668,956.