Table 2.
Predictors of infant body composition at ~5 months of age.
| Model 1 | Model 2 | Model 3 | ||||
|---|---|---|---|---|---|---|
| β (SE) | p | β (SE) | p | β (SE) | p | |
| Fat-free mass (g) | ||||||
| Race (reference = NHW) | ||||||
| Hispanic | 79 (45) | 0.08 | 53 (38) | 0.16 | 18 (36) | 0.62 |
| Black | 93 (56) | 0.10 | 201 (49) | <0.001 | 165 (46) | <0.001 |
| Other | 19 (77) | 0.80 | 44 (66) | 0.51 | 2 (63) | 0.97 |
| Pre-pregnant BMI (kg/m2) | 6 (3) | 0.05 | −1 (3) | 0.72 | 0 (2) | 0.99 |
| Gestational weight gain (kg) | 6 (3) | 0.03 | 0 (3) | 0.94 | 1 (2) | 0.56 |
| Sex (ref = male) | −482 (35) | <0.001 | −345 (31) | <0.001 | −355 (30) | <0.001 |
| GA at birth (ref = 37 weeks) | 112 (16) | <0.001 | 8 (16) | 0.61 | 16 (15) | 0.29 |
| Percent time exclusively breastfed (%) | −311 (53) | <0.001 | −417 (46) | <0.001 | −375 (44) | <0.001 |
| Fat-free mass at birth (%) | 1 (0) | <0.001 | 1 (0) | <0.001 | ||
| Rapid growth in WAZ (ref = no) | 411 (47) | <0.001 | ||||
| R2 | 0.50 | 0.64 | 0.68 | |||
| Fat mass (g) | ||||||
| Race (reference = NHW) | ||||||
| Hispanic | 267 (47) | <0.001 | 272 (46) | <0.001 | 221 (42) | <0.001 |
| Black | −141 (59) | 0.02 | −110 (59) | 0.06 | −169 (53) | 0.002 |
| Other | 88 (81) | 0.28 | 101 (80) | 0.21 | 36 (72) | 0.62 |
| Pre-pregnant BMI (kg/m2) | 3 (3) | 0.30 | 0 (3) | 0.98 | 1 (3) | 0.67 |
| Gestational weight gain (kg) | 5 (3) | 0.08 | 4 (3) | 0.26 | 6 (3) | 0.03 |
| Sex (ref = male) | 50 (37) | 0.18 | 25 (37) | 0.50 | −15 (33) | 0.65 |
| GA at birth (ref = 37 weeks) | 34 (17) | 0.05 | 21 (17) | 0.23 | 40 (16) | 0.01 |
| Percent time exclusively breastfed (%) | 224 (56) | <0.001 | 204 (55) | 0.0003 | 276 (50) | <0.001 |
| Fat mass at birth (%) | 1 (0) | <0.001 | 1 (0) | <0.001 | ||
| Rapid growth in WAZ (ref = no) | 651 (54) | <0.001 | ||||
| R2 | 0.13 | 0.16 | 0.31 | |||
| Adiposity (%) | ||||||
| Race (reference = NHW) | ||||||
| Hispanic | 2.72 (0.50) | <0.001 | 2.80 (0.49) | <0.001 | 2.36 (0.46) | <0.001 |
| Black | −1.93 (0.63) | 0.002 | −1.70 (0.62) | 0.01 | −2.23 (0.59) | 0.0002 |
| Other | 1.08 (0.86) | 0.21 | 1.22 (0.85) | 0.15 | 0.67 (0.80) | 0.40 |
| Pre-pregnant BMI (kg/m2) | 0.00 (0.03) | 0.94 | −0.03 (0.03) | 0.43 | −0.01 (0.03) | 0.63 |
| Gestational weight gain (kg) | 0.04 (0.03) | 0.25 | 0.02 (0.03) | 0.49 | 0.05 (0.03) | 0.13 |
| Sex (ref = male) | 2.30 (0.39) | <0.001 | 1.92 (0.39) | <0.001 | 1.56 (0.37) | <0.001 |
| GA at birth (ref = 37 weeks) | −0.01 (0.18) | 0.93 | −0.08 (0.18) | 0.64 | 0.10 (0.17) | 0.55 |
| Percent time exclusively breastfed (%) | 3.51 (0.59) | <0.001 | 3.36 (0.59) | <0.001 | 4.00 (0.55) | <0.001 |
| Adiposity at birth (%) | 0.22 (0.05) | <0.001 | 0.29 (0.05) | <0.001 | ||
| Rapid growth in WAZ (ref = no) | 5.57 (0.59) | <0.001 | ||||
| R2 | 0.17 | 0.19 | 0.28 | |||
NHW, non-Hispanic White; BMI, body mass index; GA, gestational age; WAZ, weight-for-age z-score
*
Estimates obtained from multivariable linear regression models conducted separately for each outcome. Other predictors considered and removed due to statistical non-significance include: maternal age, education, household income, gravidity, gestational diabetes, prenatal smoking, prenatal alcohol consumption, weeks of daily prenatal vitamin use, mode of delivery, introduction to solids, and second- and third-order interactions between pre-pregnant BMI, gestational weight gain, and breastfeeding.