Table 2. The association between weight gain in the first 4 months and BMI z-score and overweight or obesity at age 2–7 years.
| Weight gain category | N |
BMI z-score |
Overweight or obesity |
||
|---|---|---|---|---|---|
| mean ± SD | β(95%CI) | Case, No. (%) | OR(95%CI) | ||
| Total sample* | |||||
| On track | 717 | 0.62 ± 1.20 | ref | 278(38.8) | 1.0 |
| Slow growth | 424 | 0.45 ± 1.30 | −0.34(−0.48, −0.20)§ | 133(31.4) | 0.5(0.4, 0.7)§ |
| Rapid growth | 300 | 0.78 ± 1.20 | 0.36(0.20, 0.52)§ | 128(42.7) | 1.7(1.2, 2.2)§ |
| Extremely rapid | 530 | 0.89 ± 1.24 | 0.57(0.42, 0.72)§ | 244(46.0) | 2.3(1.7, 3.0)§ |
| Weight gain z-score | 0.26(0.22, 0.30)§ | 1.5(1.4, 1.7)§ | |||
| Full term | |||||
| On track | 409 | 0.76 ± 1.17 | ref | 180 (44.0) | 1.0 |
| Slow growth | 297 | 0.53 ± 1.26 | −0.32(−0.49, −0.16)§ | 101(34.0) | 0.5(0.4, 0.8)‡ |
| Rapid growth | 123 | 0.97 ± 1.10 | 0.37(0.15, 0.59)‡ | 59(48.0) | 1.5(1.0, 2.4) |
| Extremely rapid | 97 | 1.04 ± 1.18 | 0.39(0.14, 0.64)‡ | 48(49.5) | 1.6(1.0, 2.6) |
| Weight gain z-score | 0.21(0.15, 0.27)§ | 1.4(1.2, 1.6)§ | |||
| Early term | |||||
| On track | 208 | 0.45 ± 1.19 | ref | 67(32.2) | 1.0 |
| Slow growth | 102 | 0.32 ± 1.33 | −0.33(−0.61, −0.05)† | 24(23.5) | 0.4(0.2, 0.8)‡ |
| Rapid growth | 92 | 0.72 ± 1.27 | 0.34(0.06, 0.62) † | 39(42.4) | 1.7(1.0, 3.0) |
| Extremely rapid | 114 | 1.06 ± 1.15 | 0.71(0.45, 0.98) § | 62(54.4) | 3.2(1.9, 5.5)§ |
| Weight gain z-score | 0.31(0.22, 0.39)§ | 1.9(1.6, 2.3)§ | |||
| Late preterm | |||||
| On track | 74 | 0.48 ± 1.23 | ref | 23(31.1) | 1.0 |
| Slow growth | 23 | 0.01 ± 1.65 | −0.71(−1.26, −0.16)† | 7(30.4) | 0.5(0.1, 1.8) |
| Rapid growth | 58 | 0.57 ± 1.27 | 0.27(−0.14, 0.68) | 19(32.8) | 1.5(0.6, 3.5) |
| Extremely rapid | 145 | 0.95 ± 1.23 | 0.70(0.36, 1.04)§ | 70(48.3) | 3.6(1.8, 7.5)§ |
| Weight gain z-score | 0.35(0.25, 0.46)§ | 1.8(1.4, 2.3)§ | |||
| Early preterm | |||||
| On track | 26 | 0.25 ± 1.53 | ref | 8(30.8) | 1.0 |
| Slow growth | 2 | 0.49 ± 1.28 | – | 1(50.0) | – |
| Rapid growth | 27 | 0.53 ± 1.11 | 0.49(−0.21, 1.19) | 11(40.7) | 2.2(0.6, 7.8) |
| Extremely rapid | 174 | 0.65 ± 1.32 | 0.49(−0.05, 1.03) | 64(36.8) | 1.5(0.5, 4.0) |
| Weight gain z-score | 0.27(0.13, 0.42)§ | 1.3(1.0, 1.7) | |||
Gestational age category was defined as full term (gestational age ≥39 weeks), early term (37–38 weeks), late preterm (34–36 weeks), and early preterm (<34 weeks). Weight gain z-score was defined as the change in weight for age z–score between birth and 4 months and was categorized into four groups: slow (weight gain z-score less than −0.67); on track (weight gain z-score between −0.67 and 0.67), rapid (weight gain z-score between 0.67 and 1.28), and extremely rapid (weight gain z-score more than 1.28).
Adjusted for maternal education, race, smoking, parity, prepregnancy BMI category, hypertensive disorders, diabetes, fetal growth status, and breastfeeding status.
*Additional adjustment for gestational age categories. †P < 0.05; ‡P < 0.01; §P < 0.001.