Table 1 Maternal and child characteristics

Maternal characteristics

Age, years

31.5 ± 4.1

30.4 ± 4.1

Pre-pregnancy body mass index, kg/m²

23.2 ± 3.8

23.8 ± 4.5

Gestational age at serum ferritin measurement, weeks

12.8 (9.9, 17.0)

13.2 (11.0, 17.2)

Education, higher

597 (65.6)

115 (30.6)

Continued smoking during pregnancy

114 (12.5)

110 (29.3)

Serum ferritin, µg/L

61.8 (13.0, 208.2)

27.8 (5.1, 106.2)

Iron deficiency (ferritin < 15 µg/L)

31 (3.4)

86 (22.9)

Iron overload (ferritin > 150 µg/L)

85 (9.3)

2 (0.5)

Child characteristics

Sex, male

445 (48.9)

193 (51.3)

Gestational age at birth, weeks

40.4 (36.7, 42.3)

39.9 (36.9, 42.0)

Birth weight, grams

3552 ± 505

3272 ± 419