Table 1.
Population characteristics according to maternal dietary glycemic index quartiles
| Total group (n = 3471) | Glycemic index quartile 1 (n = 867) | Glycemic index quartile 2 (n = 868) | Glycemic index quartile 3 (n = 868) | Glycemic index quartile 4 (n = 868) | p valuea | |
|---|---|---|---|---|---|---|
| Maternal characteristics | ||||||
| Maternal age at enrollment, mean (SD), years | 31.4 (4.4) | 32.3 (4.0) | 31.7 (4.1) | 31.1 (4.4) | 30.4 (4.9) | 0.00 |
| Gestational age at enrollment, median (95%), weeks | 13.4 (10.6; 21.2) | 13.4 (10.9; 21.2) | 13.4 (10.5; 21.6) | 13.4 (10.6; 21.6) | 13.4 (10.4; 20.8) | 0.93 |
| Parity, n nulliparous (%) | 2076 (59.9) | 542 (62.7) | 538 (62.0) | 513 (59.2) | 483 (55.9) | 0.02 |
| Pre-pregnancy weight status, overweight, or obese, n (%) | 685 (22.9) | 138 (18.3) | 164 (22.2) | 194 (25.9) | 189 (25.3) | 0.01 |
| Gestational weight gain, mean (SD), g/week | 10.8 (4.4) | 10.7 (4.1) | 10.8 (4.5) | 10.9 (4.4) | 10.8 (4.7) | 0.71 |
| Education, n high (%) | 2026 (59.1) | 605 (70.4) | 536 (62.3) | 489 (57.3) | 396 (46.4) | 0.00 |
| Glycemic index, mean (SD) | 57.7 (3.3) | 53.8 (1.4) | 56.5 (0.6) | 58.6 (0.7) | 62.1 (1.9) | n.a. |
| Glycemic load, mean (SD) | 155 (47) | 132 (33) | 147 (39) | 160 (43) | 179 (56) | 0.00 |
| Carbohydrate intake, mean (SD), g/day | 267 (75) | 246 (60) | 261 (68) | 272 (74) | 288 (88) | 0.00 |
| Protein intake, mean (SD), g/day | 79 (19) | 82 (18) | 80 (19) | 79 (19) | 75 (20) | 0.00 |
| Fat intake, mean (SD), g/day | 86 (24) | 85 (24) | 87 (24) | 88 (25) | 85 (25) | 0.02 |
| Fiber intake, mean (SD), g/day | 23 (7) | 25 (7) | 24 (7) | 23 (7) | 21 (7) | 0.00 |
| Total energy intake, mean (SD), kcal/day | 2145 (511) | 2063 (453) | 2132 (495) | 2183 (516) | 2201 (564) | 0.00 |
| Folic acid supplement use, n yes (%) | 2532 (72.9) | 658 (75.9) | 638 (73.5) | 648 (74.7) | 588 (67.7) | 0.00 |
| Alcohol use during pregnancy, n yes (%) | 2117 (66.3) | 581 (72.8) | 554 (69.6) | 506 (63.1) | 476 (59.6) | 0.00 |
| Smoking during pregnancy, n yes (%) | 833 (26.9) | 152 (19.0) | 181 (22.5) | 226 (28.0) | 274 (33.9) | 0.00 |
| Nausea during early pregnancy, n (%) | 880 (27.7) | 181 (22.8) | 207 (26.2) | 249 (31.2) | 243 (30.5) | 0.00 |
| Vomiting during early pregnancy, n (%) | 145 (4.6) | 20 (2.5) | 36 (4.6) | 42 (5.3) | 47 (5.9) | 0.01 |
| Gestational diabetes, n (%) | 31 (0.9) | 6 (0.7) | 6 (0.7) | 9 (1.1) | 10 (1.2) | 0.64 |
| Birth characteristics | ||||||
| Sex, n male (%) | 1753 (50.5) | 404 (46.6) | 475 (54.7) | 411 (47.4) | 463 (53.3) | 0.00 |
| Gestational age at birth, median (95% range), weeks | 40.3 (37.0, 42.1) | 40.3 (36.9, 42.1) | 40.3 (37.1, 42.1) | 40.1 (37.1, 42.1) | 40.3 (36.3, 42.1) | 0.59 |
| Birthweight, mean (SD), g | 3489 (554) | 3498 (584) | 3500 (512) | 3505 (553) | 3452 (565) | 0.17 |
| Preterm birth, n (%) | 162 (4.7) | 43 (5.0) | 34 (3.9) | 30 (3.5) | 55 (6.3) | 0.02 |
| Small-for-gestational-age, n (%) | 345 (10.0) | 85 (9.8) | 82 (9.5) | 87 (10.1) | 91 (10.5) | 0.91 |
| Large-for-gestational-age, n (%) | 345 (10.0) | 105 (12.1) | 85 (9.8) | 89 (10.3) | 66 (7.6) | 0.02 |
ap values were obtained by ANOVA test for continuous variables or by Chi-square test for categorical variables