Table 2.
Association of neural tube defects with weight gain during pregnancy stratified by gestational age (< 37 weeks or ≥ 37 weeks)
| Deliveries <37 weeks | Deliveries ≥ 37 weeks | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Controls (n= 438) |
Anencephaly (n= 177) |
Spina Bifida (n=145) |
Controls (n=4773) |
Anencephaly (n= 58) |
Spina Bifida (n= 382) |
|||||
| N | N | OR 1 (95%CI) |
N | OR 1 (95%CI) |
N | N | OR 1 (95%CI) |
N | OR 1 (95%CI) |
|
| Total weight gain (kg)2 | ||||||||||
| Quartile 1 (≤ 6.67) | 117 | 106 | 3.1 (2.1,4.7) | 78 | 2.9 (1.9,4.4) | 1132 | 29 | 2.7 (1.5,4.9) | 119 | 1.1 (0.9,1.5) |
| Quartiles 2&3 (6.68–14.88) | 216 | 62 | REF | 48 | REF | 2435 | 25 | REF | 174 | REF |
| Quartile 4 (>14.88) | 105 | 9 | 0.3 (0.1,0.6) | 19 | 0.8 (0.4,1.4) | 1206 | 4 | 0.3 (0.1,1.0) | 89 | 1.1 (0.8,1.4) |
| Continuous, 25th vs. 75th percentile (8.21 unit change) | 438 | 177 | 0.58 (0.47,0.72) | 145 | 0.72 (0.59,0.88) | 4773 | 58 | 0.55 (0.42,0.72) | 382 | 0.98 (0.88,1.10) |
| Average weekly weight gain (kg)2 | ||||||||||
| Quartile 1 (≤ 0.17) | 98 | 57 | 1.3 (0.8,2.0) | 51 | 1.5 (1.0,2.4) | 1120 | 28 | 2.6 (1.5,4.6) | 117 | 1.1 (0.9,1.5) |
| Quartiles 2&3 (0.18–0.39) | 210 | 85 | REF | 65 | REF | 2493 | 26 | REF | 177 | REF |
| Quartile 4 (> 0.39) | 130 | 35 | 0.7 (0.4,1.1) | 29 | 0.7 (0.4,1.2) | 1160 | 4 | 0.3 (0.1,1.0) | 88 | 1.1 (0.8,1.4) |
| Continuous, 25th vs. 75th percentile (0.22 unit change) | 438 | 177 | 0.87 (0.76,1.01) | 145 | 0.88 (0.75,1.04) | 4773 | 58 | 0.53 (0.40,0.71) | 382 | 1.00 (0.90,1.12) |
Adjusted for maternal race-ethnicity (non-Hispanic white, non-Hispanic black, Hispanic, other), education (<12, 12, >12 years), pre-pregnancy BMI (<18.5, 18.5–24.9, 25.0–29.9, ≥ 30 kg/m2), intake of folic acid-containing supplements during the month before and the first three months of pregnancy (any versus none), maternal total energy intake (kcal/day), and dietary folate intake (dietary folate equivalents, µg/day). Analyses included subjects with complete data on all covariates.
Birth weight was subtracted from total weight gain, and average weekly weight gain was obtained by dividing the total weight gain (minus birth weight) with gestational duration in weeks.