Table 2 Characteristics of participants (n = 1379)
|  | Total group (n = 1379) |
|---|---|
Maternal characteristics | |
 Age, mean (SD), years | 30.5 (4.8) |
 Parity, No. nulliparous (%) | 839 (61.2) |
 Educational level, No. low (%) | 102 (7.4) |
 Ethnicity, No. European (%) | 846 (61.9) |
 Folic acid supplement use, No. yes (%) | 887 (80.6) |
 Smoking, No. nonsmoking (%) | 939 (75.5) |
  First trimester, No. nonsmoking (%) | 952 (78.4) |
  Second trimester, No. nonsmoking (%) | 1055 (88.7) |
  Third trimester, No. nonsmoking (%) | 1050 (89.3) |
 Alcohol consumption, No. no alcohol use (%) | 527 (42.6) |
  First trimester, No. no alcohol use (%) | 616 (50.5) |
  Second trimester, No. no alcohol use (%) | 777 (65.6) |
  Third trimester, No. no alcohol use (%) | 747 (63.5) |
 Pre-pregnancy body mass index, median (95% range), kg/m2 | 22.7 (18.5, 34.9) |
 Daily caloric intake, mean (SD), kcal | 2078.1 (511.2) |
Fetal growth characteristics | |
 Second trimester | |
  Gestational age, median (95% range), weeks | 20.4 (18.9, 22.7) |
  Head circumference, mean (SD), mm | 178.0 (12.0) |
  Femur length, mean (SD), mm | 33.2 (2.9) |
  Estimated fetal weight, mean (SD), g | 369.2 (72.7) |
 Third trimester | |
  Gestational age, median (95% range), weeks | 30.4 (28.7, 32.6) |
  Head circumference, mean (SD), mm | 285.9 (11.5) |
  Femur length, mean (SD), mm | 57.5 (2.8) |
  Estimated fetal weight, mean (SD), g | 1620.5 (236.5) |
Birth characteristics | |
 Males, No. (%) | 696 (50.5) |
 Gestational age, median (95% range), weeks | 40.3 (36.7, 42.3) |
 Birth weight, mean (SD), g | 3453.9 (498.5) |
 Birth length, mean (SD), cm | 50.3 (2.3) |
 Birth head circumference, mean (SD), cm | 33.8 (1.7) |
 Preterm birth, No. (%) | 35 (2.5) |
 Small size for gestational age, No. (%) | 114 (8.3) |