Table 3.
Infant outcomes, overall and according to maternal body mass index adjusted for length of gestation (adjBMI) at enrollment
| Maternal adjBMI (kg/m2) at Enrollment | ||||||
|---|---|---|---|---|---|---|
| Underweight | Normal | Over-Weight | Obese | |||
| Overall | (≥10.0 - <19.8) | (≥19.8 - <26.1) | (≥26.1 - <29.0) | (≥29.0 - <50.0) | ||
| Infant outcome | N=697 | n=109 | n=418 | n=88 | n=82 | P value1 |
| Gestational age at birth (weeks): | ||||||
| Mean (SD) | 38.4 (1.7) | 38.0 (2.0) | 38.5 (1.5) | 38.5 (1.6) | 38.4 (2.3) | |
| Median | 39.0 | 38.0 | 39.0 | 39.0 | 39.0 | 0.069 |
| Birth weight (grams): | ||||||
| Mean (SD) | 3005 (519) | 2753 (567) | 3022 (466) | 3142 (496) | 3105 (625) | |
| Median | 3000 | 2700 | 3000 | 3000 | 3200 | <0.0001 |
| BMI at birth: | ||||||
| Mean (SD) | 13.0 (1.6) | 12.4 (1.7) | 13.0 (1.6) | 13.3 (1.3) | 13.1 (2.0) | |
| Median | 13.0 | 12.5 | 13.1 | 13.2 | 13.1 | 0.0002 |
| Birth length (centimeters): | ||||||
| Mean (SD) | 48.0 (2.7) | 46.9 (3.0) | 48.2 (2.5) | 48.5 (2.5) | 48.5 (3.1) | |
| Median | 48.0 | 47.0 | 48.0 | 48.8 | 49.0 | <0.0001 |
| Head circumference at birth (centimeters): | ||||||
| Mean (SD) | 33.9 (1.7) | 33.2 (1.9) | 34.0 (1.5) | 34.3 (1.4) | 34.1 (2.1) | |
| Median | 34.0 | 33.5 | 34.0 | 34.5 | 34.0 | <0.0001 |
1
The p-values for associations between maternal adjBMI at enrollment and infant outcomes are based on the non-parametric Kruskal-Wallis test of equality of means.