Table 1 Distribution of maternal characteristics based on the presence or absence of pre-existing and gestational comorbidities

Maternal age

 15–19

 20–24

 25–29

 30–34

 35–39

 40–44

 45–49

19.3 (19.3–19.4)

30.4 (30.4–30.5)

26.2 (26.1–26.2)

17.3 (17.3–17.4)

5.7 (5.7–5.7)

1.0 (1.0–1.0)

0.1 (0.1–0.1)

9.7 (9.5–9.9)

23.4 (23.1–23.7)

28.3 (27.9–28.6)

23.1 (22.8–23.4)

12.0 (11.8–12.3)

3.3 (3.1–3.4)

0.2 (0.2–0.3)

9.7 (9.2–10.2)

25.2 (24.5–25.9)

27.7 (26.9–28.4)

22.5 (21.8–23.2)

11.7 (11.2–12.3)

3.1 (2.8–3.4)

0.2 (0.1–0.3)

21.0 (20.8–21.1)

31.1 (31.0–31.3)

26.2 (26.1–26.4)

15.1 (15.0–15.3)

5.4 (5.3–5.5)

1.1 (1.0–1.1)

0.1 (0.1–0.1)

7.8 (7.6–7.9)

22.5 (22.2–22.8)

30.2 (29.9–30.5)

25.5 (25.2–25.8)

11.2 (11.0–11.4)

2.7 (2.6–2.8)

0.2 (0.2–0.2)

27.1 (26.7–27.6)

30.9 (30.4–31.4)

22.5 (22.1–23.0)

13.0 (12.6–13.3)

5.2 (5.0–5.5)

1.1 (1.0–1.2)

0.1 (0.1–0.1)

Maternal race

 Non-Hispanic White

 Non-Hispanic Black

 Hispanic

 American Indian/Alaska Native

 Asian/Pacific Islander

 Other

57.4 (57.4–57.5)

12.7 (12.7–12.8)

21.0 (21.0–21.1)

0.7 (0.7–0.7)

7.0 (6.9–7.0)

1.1 (1.1–1.2)

65.2 (64.8–65.6)

21.4 (21.0–21.7)

9.0 (8.8–9.3)

0.9 (0.9–1.0)

2.8 (2.7–3.0)

0.6 (0.5–0.7)

57.6 (56.8–58.5)

17.1 (16.5–17.7)

16.8 (16.1–17.4)

1.5 (1.3–1.7)

5.7 (5.3–6.1)

1.3 (1.1–1.5)

68.3 (68.2–68.5)

15.1 (15.0–15.2)

12.5 (12.4–12.6)

1.1 (1.1–1.2)

2.4 (2.4–2.5)

0.5 (0.4–0.5)

56.6 (56.3–56.9)

10.3 (10.1–10.5)

17.5 (17.2–17.7)

0.9 (0.9–1.0)

13.5 (13.3–13.7)

1.2 (1.1–1.2)

60.1 (59.6–60.7)

20.7 (20.3–21.2)

14.5 (14.1–14.9)

1.8 (1.7–2.0)

2.4 (2.3–2.6)

0.3 (0.3–0.4)

Did not graduate high school

16.8 (16.7–16.8)

10.5 (10.2–10.7)

13.7 (13.1–14.3)

17.0 (16.9–17.1)

10.8 (10.6–11.0)

22.5 (22.1–23.0)

Not married

47.5 (47.4–47.6)

37.7 (37.3–38.1)

46.1 (45.2–46.9)

42.1 (41.9–42.2)

36.7 (36.3–37.0)

46.1 (45.6–46.7)

Current smoker

17.2 (17.1–17.2)

16.1 (15.9–16.4)

18.5 (17.8–19.1)

14.7 (14.6–14.9)

15.1 (14.9–15.3)

13.3 (12.9–13.6)

Gestational weight gain ≥40 lbs

30.0 (29.9–30.1)

28.4 (28.0–28.8)

29.2 (28.430.0)

40.0 (39.8–40.2)

22.3 (22.0–22.6)

37.4 (36.8–38.0)

Delivered via cesarean section

27.6 (27.5–27.6)

48.7 (48.3–49.1)

60.3 (59.5–61.2)

41.6 (41.4–41.7)

42.4 (42.1–42.7)

51.5 (51.0–52.1)

Small for gestational age infant (< 10th centile)

11.5 (11.4–11.5)

17.9 (17.6–18.2)

10.7 (10.2–11.2)

18.4 (18.3–18.6)

11.5 (11.3–11.7)

24.9 (24.4–25.4)

Large for gestational age infant (> 90th centile)

6.8 (6.8–6.8)

7.6 (7.3–7.8)

18.1 (17.4–18.7)

7.4 (7.3–7.5)

10.0 (9.8–10.2)

6.0 (5.7–6.2)

Preterm birth (gestational age < 37 weeks)

7.4 (7.4–7.4)

20.1 (19.7–20.4)

23.8 (23.1–24.6)

18.1 (18.0–18.3)

11.6 (11.4–11.8)

31.5 (31.0–32.0)