Table 1 Characteristics^a of study participants

Mothers (n (%))

51,125 [100.0]

31,787 [62.2]

7805 [15.3]

11,533 [22.5]

 Maternal age (years)

27.6 [4.19]

27.2 [4.08]

25.9 [3.74]

29.6 [4.39]

 Primiparous (n (%))

34,876 [68.2]

21,791 [68.6]

5451 [69.8]

7634 [66.2]

 Single mother (n (%))

1380 [2.7]

998 [3.1]

197 [2.5]

185 [1.6]

 Gestational weight gain (kg)

13.1 [4.17]

13.4 [3.95]

14.1 [3.77]

11.5 [4.55]

 GDM (n (%))

10,361 [20.3]

5722 [18.0]

932 [11.9]

3706 [32.1]

 Preeclampsia (n (%))

804 [1.6]

368 [1.2]

58 [0.7]

378 [3.3]

 Cesarean delivery (n (%))

29,720 [58.1]

18,219 [57.3]

3657 [46.9]

7841 [68.0]

 Gender, girl (n (%))

26,506 [51.9]

16,551 [52.1]

3918 [50.2]

6034 [52.4]

 Preterm delivery (n (%))

2645 [5.2]

1514 [4.8]

387 [5.0]

744 [6.5]

 Stillbirth (n (%))

588 [1.2]

317 [1.0]

78 [1.0]

193 [1.7]

 Gestational age at delivery (wks)

39.0 [1.98]

39.1 [1.89]

39.1 [1.85]

38.8 [2.26]

 Birth weight (kg)

3.26 [0.49]

3.26 [0.47]

3.15 [0.45]

3.32 [0.55]

 Birth length (cm)

49.4 [2.61]

49.5 [2.48]

49.2 [2.50]

49.4 [3.01]

 Macrosomia (n (%))

2104 [4.1]

1186 [3.7]

119 [1.5]

799 [6.9]

 Small for gestational age (n (%))

677 [1.3]

405 [1.3]

147 [1.9]

125 [1.1]

 Large for gestational age (n (%))

554 [1.1]

310 [1.0]

30 [0.4]

214 [1.9]