Table 2 Distributions of gestational age, total GWG, and GWG Z−scores by case−control statusa
From: The association between gestational weight gain z-score and stillbirth: a case-control study
|  | Stillbirths (n = 479) | Live births (n = 1601) | ||||
|---|---|---|---|---|---|---|
Gestational age at delivery, weeks | Mean | SD | Mean | SD | ||
29.60 | 6.6 | 38.64 | 2.1 | |||
Estimated gestational age at fetal death, weeks (stillbirths only)b | Mean | SD |  | |||
28.58 | 7.0 | |||||
Total GWG, lb | Mean | SD | Mean | SD | ||
 Total sample (All BMI Categories) | 18.95 | 17.6 | 30.89 | 13.3 | ||
 Underweight (BMI < 18.5 kg/m2) | 25.23 | 19.9 | 35.12 | 10.3 | ||
 Normal weight (BMI 18.5 − < 25.0 kg/m2) | 21.65 | 15.2 | 33.90 | 11.7 | ||
 Overweight (BMI 25.0 − < 30.0 kg/m2) | 22.13 | 19.5 | 30.75 | 12.8 | ||
 Class 1 obese (BMI 30.0 − < 35.0 kg/m2) | 15.96 | 17.5 | 26.24 | 14.0 | ||
 Classes 2–3 obese (BMI ≥35.0 kg/m2) | 9.55 | 15.7 | 21.90 | 16.2 | ||
GWG Z−scores | Mean | Median | SD | Mean | Median | SD |
 Total sample (All BMI Categories) | −0.39 | −0.26 | 1.5 | −0.17 | −0.10 | 0.9 |
 Underweight (BMI < 18.5 kg/m2) | −0.23 | −0.80 | 1.8 | 0.14 | 0.26 | 0.9 |
 Normal weight (BMI 18.5 − < 25.0 kg/m2) | − 0.63 | − 0.40 | 1.8 | − 0.20 | − 0.17 | 1.0 |
 Overweight (BMI 25.0 − < 30.0 kg/m2) | − 0.26 | −0.30 | 1.3 | −0.26 | −0.17 | 0.8 |
 Class 1 obese (BMI 30.0 − < 35.0 kg/m2) | − 0.31 | − 0.17 | 1.2 | −0.17 | −0.19 | 0.9 |
 Classes 2–3 obese (BMI ≥35.0 kg/m2) | −0.12 | −0.01 | 1.1 | 0.09 | 0.24 | 0.7 |