Case mothers n = 306 Control mothers n = 424
Missings
P-value
Demographics
Maternal age, years* 31.8 (4.7) 30.9 (4.6) 1 0.009
Time after index-pregnancy, months 16.2 [15.2, 17.9] 16.3 [15.3, 18.0] 1 0.79
Mode of conception, spontaneous 289 (94.4) 401 (94.6) 1 0.82
Body mass index, [kg/m2] 24.0 [22.0, 28.0] 24.0 [22.0, 27.0] 1 0.25
Education level Low Intermediate High 86 (28.1) 126 (41.2) 94 (30.7) 93 (22.1) 216 (51.3) 112 (26.6)
3
0.02
Geographic origin Western Non-Western 270 (88.2) 36 (11.8) 356 (84.2) 67 (15.8)
1
0.15
Mother with COD 8 (2.6) 4 (0.9) 0 0.15
Family history of COD 43 (14.1) 31 (7.3) 0 0.009
Lifestyle
Periconception use of (n (%))
Alcohol 113 (36.9) 138 (32.5) 4 0.51
Cigarettes 57 (18.6) 87 (20.5) 0 0.56
Folic acid and/or (multi)vitamins 254 (83.0) 339 (80.1) 0 0.38
Current use of (n (%))
Alcohol 157 (51.3) 233 (55.0) 1 0.47
Cigarettes 53 (17.3) 78 (18.4) 2 0.57
Folic acid and/or (multi)vitamins 83 (27.1) 107 (25.3) 0 0.64
Biomarkers
Vitamine B12, serum (pmol/L) 277.5 [209.5, 361.8] 260.0 [201.0, 357.5] 0 0.36
Plasma total homocysteine, plasma, (umol/L) 10.1 [8.4, 12.5] 9.7 [8.2, 11.8] 0 0.05
folate, serum (nmol/L) 15.2 [12.4, 19.4] 14.70 [12.2, 19.6] 0 0.37
folate, red blood cell (nmol/L) 659 [529, 802] 634 [521, 769] 0 0.36
Birth outcomes
Foetal gender, boys 173 (56.5) 234 (55.2) 0 0.78
Birthweight 3,290 [2,850, 3,650] 3,500 [3,200, 3,890] 1 <0.001
Preterm birth(< 37 weeks gestation) 48 (15.8) 24 (5.7) 4 <0.001