Table 3. Associations between natural log-transformed maternal serum folate concentration during the first trimester and neural crest cell-derived birth defects after 12 weeks of gestation compared with mothers of infants without birth defects.
| Number of infants with birth defects |
Maternal serum folate (nmol/L) |
Crude ORs (95% CIs) |
Adjusted ORs (95% CIs) |
|
| All birth NCC defects | 161 | 16.5 (13.5, 21.7) | 1.09 (0.73–1.62) | 1.02 (0.65–1.58) |
| NTDs, Q00,01,05 | 6 | 19.9 (14.9, 26.5) | 2.52 (0.37–17.25) | 2.01 (0.21–19.05) |
| CHDs, Q20–28 | 125 | 16.5 (13.4, 20.6) | 0.94 (0.60–1.48) | 0.83 (0.50–1.37) |
| CHDs classifications | ||||
| Septal heart defects, Q21.0–21.1 | 80 | 16.4 (13.3, 21.0) | 1.04 (0.59–1.82) | 0.91 (0.49–1.70) |
| Conotruncal heart defects, Q20.0, 20.1, 20.3, 21.3 | 5 | 16.5 (15.9, 20.6) | 1.01 (0.11–9.49) | 0.74 (0.08–7.19) |
| Left ventricle outflow obstruction, Q23.0, 23.3–4, 25.1–3 | 9 | 14.9 (12.9, 16.5) | 0.30 (0.05–1.76) | 0.23 (0.03–1.68) |
| Right ventricle outflow obstruction Q21.3, 22.1, 22.5, 25. 6 | 17 | 16.1 (13.8, 26.3) | 1.11 (0.33–3.71) | 0.91 (0.25–3.27) |
| CHDs phenotype | ||||
| Ventricular septal defects, Q21.0 | 61 | 16.3 (12.7, 19.9) | 0.73 (0.38–1.40) | 0.63 (0.30–1.33) |
| Atrial septal defects, Q21.1 | 12 | 22.2 (13.7, 30.5) | 3.30 (0.86–12.62) | 2.27 (0.49–10.53) |
| Pulmonary valve stenosis, Q22.1 | 17 | 16.1 (13.8, 26.3) | 1.19 (0.36–3.95) | 0.93 (0.26–3.31) |
| Orofacial cleft phenotype | ||||
| Cleft lip with or without cleft palate, Q36–37 | 13 | 19.0 (15.9, 21.3) | 2.25 (0.60–8.38) | 4.10 (0.96–17.58) |
| Cleft palate (alone), Q35 | 8 | 18.9 (13.9, 22.7) | 0.81 (0.13–4.87) | 0.47 (0.06–3.62) |
| Hypospadias, Q54 | 4 | 21.6 (12.1, 35.1) | 2.86 (0.28–29.65) | 1.86 (0.10–34.66) |
| Limb reduction, Q71–72 | 2 | 16.8 (15.9, 17.7) | 0.83 (0.02–30.19) | 2.92 (0.05–157.08) |
CHDs, congenital heart defects; CI, confidence interval; NCCs, neural crest cells; NTDs, neural tube defects; OR, odds ratio.
Serum folate, median (interquartile range). Serum folate level of women who had infants without birth defects was 16.5 nmol/L.
ORs (with 95% CIs) per log-transformed folate concentration in maternal serum folate.
Adjusted for maternal age (continuous variable), parity, educational level (years), assisted reproductive technology, smoking, alcohol, body mass index (continuous variable), and medication use.