Table 2.
The association of maternal vitamin D concentrations and pregregnancy BMI categories with CRL in early pregnancy
| Maternal characteristic | Effect size for CRL standard deviation score (SDS),1 SDS = 6.5 mm | Restricted fetal growth (CRL < 20th percentile) | ||||
|---|---|---|---|---|---|---|
| Mean (SE) | Adjusted mean differences (95% CI) | P | n (%) | Adjusted OR (95% CI) |
P | |
| Vitamin D binary | ||||||
| SUFFa | 0.06 (0.02) | 0 [Reference] | 1 [Reference] | 928 (18.3) | 0 [Reference] | 1 [Reference] |
| INSUFF/DEFb | 0.01 (0.01) | − 0.05 (− 0.08, − 0.02) | 0.005 | 2202 (20.8) | 1.13 (1.04, 1.24) | 0.004 |
| Vitamin D, nmol/L | ||||||
| p5(< 20.0) | − 0.03 (0.04) | − 0.08 (− 0.18, 0.02) | 0.12 | 164 (21.5) | 1.31 (1.01, 1.71) | 0.04 |
| p5-p25(20.0 -30.5) | − 0.004 (0.02) | − 0.07 (− 0.15, 0.003) | 0.06 | 627 (20.0) | 1.23 (1.00, 1.52) | 0.06 |
| p25-p50(30.6 -41.6) | − 0.03 (0.02) | − 0.11 (− 0.19, − 0.04) | 0.004 | 826 (21.1) | 1.35 (1.09, 1.66) | 0.005 |
| p50-p75(41.7 -53.5) | − 0.02 (0.02) | − 0.10 (− 0.18, − 0.03) | 0.009 | 810 (20.6) | 1.31 (1.07, 1.62) | 0.01 |
| p75-p95(53.6 -70.4) | 0.03 (0.02) | − 0.07 (− 0.15, 0.01) | 0.08 | 578 (18.5) | 1.16 (0.94, 1.44) | 0.16 |
| p95-p100(≥ 70.5) | 0.12 (0.03) | 0 [Reference] | 125 (15.8) | 0 [Reference] | ||
| P for trend | 0.002 | 0.003 | ||||
| BMI, kg/m2 | ||||||
| Underweight (< 18.5) | 0.08 (0.02) | 0.04 (− 0.01, 0.08) | 0.11 | 402 (19.4) | 0.95 (0.84, 1.07) | 0.37 |
| Normal weight (18.5–23.9) | 0.05 (0.01) | 0 [Reference] | 1 [Reference] | 2273 (19.2) | 0 [Reference] | 1 [Reference] |
| OWO (≥ 24) | − 0.15 (0.02) | − 0.20 (− 0.25, − 0.15) | < 0.0001 | 455 (26.0) | 1.58 (1.40, 1.78) | < 0.0001 |
| P for trend | < 0.0001 | < 0.0001 | ||||
n = 15,651. General linear regression models provide regression coefficients (β) for the standard deviation score (SDS) in CRL. Logistic regression models provide OR (95% CI) for the risk in restricted fetal growth (CRL < 20th centile). Analyses were adjusted for maternal age, parity, season at vitamin D testing, fetal sex
BMI body mass index, CRL crown-rump length, OWO overweight or obese
aSUFF (sufficient), 25(OH)D in serum ≥ 50.00 nmol/L
bINSUFF/DEF (insufficient or deficient), 25(OH)D in serum < 50.00 nmol/L