Table 1.
Mothers' and children's characteristics grouped by birth weight and overweight/obesity at age 3 years (N=1581)
| Birth weight | Weight at 3 years of age | ||||||
|---|---|---|---|---|---|---|---|
| Characteristics | Total | Low birth weight (<2500 g) | Normal birth weight (≥2500 g) | P‐value | Normal | Overweight/obese | P‐value |
| Number of children | 1,581 | 130 | 1397 | 1481 | 93 | ||
| Children's factors | |||||||
| Boys | 788 (49.8) | 54 (41.5) | 712 (51.0) | .040 | 746 (50.4) | 38 (40.9) | .075 |
| Girls | 793 (50.2) | 76 (58.5) | 685 (49.0) | 735 (49.6) | 55 (59.1) | ||
| Birth ordera | |||||||
| First birth | 692 (43.8) | 60 (46.5) | 632 (45.4) | .705 | 646 (45.4) | 40 (44.4) | .984 |
| Second birth | 564 (35.7) | 44 (34.1) | 520 (37.4) | 530 (37.3) | 34 (37.8) | ||
| Third birth and more | 264 (16.7) | 25 (19.4) | 239 (17.2) | 247 (17.4) | 16 (17.8) | ||
| Birth weight (g) | |||||||
| Mean (SD) | 3037.9 (438.3) | 2178.6 (392.8) | 3117.8 (347.2) | <.001 | 3029.3 (435.5) | 3175.8 (457.9) | .002 |
| Birth weighta | |||||||
| <2500 g | 130 (8.2) | 130 (100.0) | 0 (0.0) | < .001 | 125 (8.4) | 4 (4.3) | .171 |
| 2500‐3999 g (reference) | 1376 (87.0) | 0 (0.0) | 1,376 (98.5) | 1,288 (87.0) | 82 (88.2) | ||
| ≥4000 g | 21 (1.3) | 0 (0.0) | 21 (1.5) | 17 (1.2) | 4 (4.3) | ||
| Gestational agea | |||||||
| Mean (SD) | 38.9 (1.6) | 36.3 (2.8) | 39.1 (1.3) | <.001 | 38.9 (1.6) | 39.0 (1.7) | .135 |
| <37 (preterm) | 82 (5.2) | 49 (37.7) | 33 (2.4) | <.001 | 76 (5.2) | 5 (5.6) | .892 |
| BMI at age 18 months, mean (SD)a | 15.9 (1.1) | 15.7 (1.14) | 16.0 (1.12) | .004 | 15.9 (1.10) | 16.5 (1.13) | <.001 |
| BMI at age 3 years, mean (SD)a | 16.0 (1.1) | 15.5 (1.23) | 16.0 (1.12) | <.001 | 15.9 (1.07) | 16.8 (1.34) | <.001 |
| BMI at age 15 years, mean (SD)a | 20.3 (3.0) | 19.9 (3.5) | 20.3 (2.9) | .178 | 20.1 (2.7) | 23.4 (4.3) | <.001 |
| Overweight/obese at age 15 years | 167 (10.6) | 18 (14.0) | 147 (10.7) | .252 | 135 (9.2) | 31 (33.7) | <.001 |
| Maternal factors | |||||||
| Mother's age at pregnancy | |||||||
| <20 years | 45 (2.9) | 4 (3.1) | 39 (2.8) | .907 | 42 (2.8) | 3 (3.2) | .704 |
| 20–35 years | 1417 (89.6) | 115 (88.5) | 1253 (89.7) | 1329 (89.7) | 81 (87.1) | ||
| ≥35 years | 119 (7.5) | 11 (8.5) | 105 (7.5) | 110 (7.4) | 9 (9.7) | ||
| Prepregnancy BMI, mean (SD)a | 20.5 (2.8) | 20.1 (3.0) | 20.5 (2.7) | .066 | 20.4 (2.7) | 21.6 (3.2) | <.001 |
| Underweight | 310 (19.6) | 35 (26.9) | 265 (19.0) | .090 | 299 (20.2) | 10 (10.8) | .079 |
| Overweight/obese | 93 (5.9) | 8 (6.2) | 83 (5.9) | .202 | 81 (5.5) | 12 (12.9) | .028 |
| Having full‐time jobs | 637 (40.3) | 59 (45.4) | 568 (40.7) | .295 | 588 (39.7) | 44 (47.3) | .147 |
| History of abortion | 102 (6.5) | 6 (4.6) | 93 (6.7) | .366 | 101 (6.8) | 1 (1.1) | .029 |
| History of spontaneous abortion | 228 (14.4) | 19 (14.6) | 206 (14.8) | .968 | 212 (14.3) | 14 (15.1) | .844 |
| Prenatal smokingb | 160 (10.1) | 16 (12.5) | 140 (10.5) | .481 | 141 (9.9) | 17 (19.8) | .004 |
| Prenatal alcohol intakeb | 422 (26.7) | 34 (27.0) | 377 (28.4) | .742 | 387 (27.4) | 31 (36.1) | .083 |
Note. Data are shown as number and percentage or mean and standard deviation.
Abbreviations: BMI: body mass index; SD: standard deviation.
a
Numbers (percentages) of subjects with missing data were reported for the following variables: birth order, 61 (3.9%); birth weight, 54 (3.4%); gestational age, 28 (1.8%); BMI at age 18 months, 1 (0.06%); BMI at age 3 years, 7 (0.4%); BMI at age 15 years, 19 (1.2%); maternal prepregnancy BMI, 118 (7.5%); smoking status of mothers, 68 (4.3%); and alcohol intake of mothers, 76 (4.8%).
b
Responses to smoking or alcohol intake statuses were yes, no, or sometimes.