Table 1 Characteristics of the participants stratified by feeding practice and period. Rio de Janeiro, Brazil, 2018

 Sex

female

48.1 (43.6–52.6)

46.6 (39.7–53.7)

48.1 (34.3–62.2)

49.3 (43.6–55.1)

53.0 (45.1–60.8)

39.7 (27.0–53.4)

43.1 (34.6–51.8)

50.6 (44.0–57.3)

42.9 (32.5–53.7)

male

51.9 (47.4–56.4)

53.4 (46.3–60.3)

51.9 (37.8–65.7)

50.7 (44.9–56.4)

47.0 (39.2–54.9)

60.3 (46.6–73.0)

56.9 (48.2–65.4)

49.4 (42.7–56.0)

57.1 (46.3–67.5)

 Multiple births

no

87.7 (84.5–90.4)

76.0 (69.6–81.6)

79.6 (66.5–89.4)

93.0 (89.6–95.6)

70.5 (62.9–77.3)

74.1 (61.0–84.7)

95.6 (90.7–98.4)

92.6 (88.5–95.7)

71.4 (61.0–80.4)

yes

12.3 (9.6–15.5)

24.0 (18.4–30.4)

20.4 (10.6–33.5)

7.0 (4.4–10.4)

29.5 (22.7–37.1)

25.9 (15.3–39.0)

4.4 (1.6–9.3)

7.4 (4.3–11.5)

28.6 (19.6–39.0)

 Gestational age (weeks)

>  37

85.7 (82.3–88.6)

68.8 (62.0–75.0)

42.6 (29.2–56.8)

89.1 (85.0–92.4)

72.3 (64.8–78.9)

60.3 (46.6–73.0)

89.1 (82.6–93.7)

88.3 (83.5–92.2)

60.4 (49.6–70.5)

<  37

14.3 (11.4–17.7)

31.2 (25.0–38.0)

57.4 (43.2–70.8)

10.9 (7.6–15.0)

27.7 (21.1–35.2)

39.7 (27.0–53.4)

10.9 (6.3–17.4)

11.7 (7.8–16.5)

39.6 (29.5–50.4)

 Birth weight

ELBW

0.4 (0.0–1.5)

0.5 (0.0–2.6)

9.3 (3.1–20.3)

0.0 (0.0–1.2)

1.2 (0.1–4.3)

0.0 (0.0–6.2)

0.0 (0.0–2.7)

0.4 (0.0–2.4)

2.2 (0.3–7.7)

VLBW

0.2 (0.0–1.1)

1.9 (0.5–4.9)

16.7 (7.9–29.3)

0.7 (0.1–2.4)

1.8 (0.4–5.2)

5.2 (1.1–14.4)

0.7 (0.0–4.0)

0.9 (0.1–3.1)

5.5 (1.8–12.4)

LBW

10.1 (7.6–13.1)

27.9 (21.9–34.5)

20.4 (10.6–33.5)

10.6 (7.4–14.6)

21.7 (15.7–28.7)

20.7 (11.2–33.4)

9.5 (5.1–15.7)

10.8 (7.1–15.6)

25.3 (16.7–35.5)

> 2500 g

89.3 (86.2–91.9)

69.7 (63.0–75.9)

53.7 (39.6–67.4)

88.7 (84.6–92.1)

75.3 (68.0–81.7)

74.1 (61.0–84.7)

89.8 (83.4–94.3)

87.9 (83.0–91.8)

67.0 (56.4–76.5)

 Perinatal morbidity

no

69.3 (65.0–73.3)

48.1 (41.1–55.1)

0.0 (0.0–6.6)

71.9 (66.4–76.9)

54.2 (46.3–62.0)

37.9 (25.5–51.6)

70.1 (61.7–77.6)

70.6 (64.2–76.4)

34.1 (24.5–44.7)

yes

30.7 (26.7–35.0)

51.9 (44.9–58.9)

100.0 (93.4–100.0)

28.1 (23.1–33.6)

45.8 (38.0–53.7)

62.1 (48.4–74.5)

29.9 (22.4–38.3)

29.4 (23.6–35.8)

65.9 (55.3–75.5)

 Hospital readmission

no

–

–

–

95.7 (92.8–97.7)

92.8 (87.7–96.2)

82.8 (70.6–91.4)

97.1 (92.7–99.2)

93.9 (90.0–96.6)

91.2 (83.4–96.1)

yes

–

–

–

4.3 (2.3–7.2)

7.2 (3.8–12.3)

17.2 (8.6–29.4)

2.9 (0.8–7.3)

6.1 (3.4–10.0)

8.8 (3.9–16.6)

 Maternal age

<  20 y.o.

10.9 (8.3–14.0)

6.2 (3.4–10.5)

20.4 (10.6–33.5)

10.3 (7.1–14.3)

6.6 (3.4–11.5)

8.6 (2.9–19.0)

8.0 (4.1–13.9)

10.0 (6.4–14.6)

9.9 (4.6–17.9)

from 20 to 34 y.o.

69.7 (65.4–73.7)

76.0 (69.6–81.6)

59.3 (45.0–72.4)

71.5 (66.1–76.5)

68.7 (61.0–75.6)

74.1 (61.0–84.7)

75.9 (67.9–82.8)

63.6 (57.1–69.8)

73.6 (63.3–82.3)

>  35 y.o.

19.4 (16.0–23.2)

17.8 (12.8–23.7)

20.4 (10.6–33.5)

18.2 (14.0–23.0)

24.7 (18.3–32.0)

17.2 (8.6–29.4)

16.1 (10.3–23.3)

26.4 (20.8–32.6)

16.5 (9.5–25.7)

 Maternal education

up to elementary school

32.3 (28.2–36.6)

34.1 (27.7–41.0)

38.9 (25.9–53.1)

27.8 (22.8–33.2)

33.1 (26.0–40.8)

31.0 (19.5–44.5)

27.0 (19.8–35.3)

25.5 (20.0–31.7)

31.9 (22.5–42.5)

secondary school or higher

67.7 (63.4–71.8)

65.9 (59.0–72.3)

61.1 (46.9–74.1)

72.2 (66.8–77.2)

66.9 (59.2–74.0)

69.0 (55.5–80.5)

73.0 (64.7–80.2)

74.5 (68.3–80.0)

68.1 (57.5–77.5)

 Household income ^a

less than $576

37.8 (33.5–42.2)

38.9 (32.3–45.9)

51.9 (37.8–65.7)

37.1 (31.6–42.8)

36.1 (28.8–44.0)

46.6 (33.3–60.1)

41.6 (33.3–50.3)

34.2 (28.1–40.7)

38.5 (28.4–49.2)

over $576

62.2 (57.8–66.5)

61.1 (54.1–67.7)

48.1 (34.3–62.2)

62.9 (57.2–68.4)

63.9 (56.0–71.2)

53.4 (39.9–66.7)

58.4 (49.7–66.7)

65.8 (59.3–71.9)

61.5 (50.8–71.6)

 Parity and PEBF

primiparous

49.5 (45.0–54.0)

45.2 (38.3–52.2)

63.0 (48.7–75.7)

51.3 (45.5–57.1)

47.6 (39.8–55.5)

43.1 (30.2–56.8)

54.0 (45.3–62.6)

50.2 (43.6–56.8)

45.1 (34.6–55.8)

multiparous with PEBF

46.1 (41.6–50.6)

47.1 (40.2–54.1)

35.2 (22.7–49.4)

45.0 (39.3–50.8)

46.4 (38.6–54.3)

41.4 (28.6–55.1)

43.1 (34.6–51.8)

44.6 (38.1–51.2)

42.9 (32.5–53.7)

multiparous without PEBF

4.4 (2.8–6.7)

7.7 (4.5–12.2)

1.9 (0.0–9.9)

3.6 (1.8–6.4)

6.0 (2.9–10.8)

15.5 (7.3–27.4)

2.9 (0.8–7.3)

5.2 (2.7–8.9)

12.1 (6.2–20.6)

 Gestational morbidity

no

53.5 (49.0–58.0)

46.2 (39.2–53.2)

48.1 (34.3–62.2)

54.0 (48.2–59.7)

54.2 (46.3–62.0)

53.4 (39.9–66.7)

57.7 (48.9–66.1)

49.8 (43.2–56.4)

57.1 (46.3–67.5)

yes

46.5 (42.0–51.0)

53.8 (46.8–60.8)

51.9 (37.8–65.7)

46.0 (40.3–51.8)

45.8 (38.0–53.7)

46.6 (33.3–60.1)

42.3 (33.9–51.1)

50.2 (43.6–56.8)

42.9 (32.5–53.7)

 Maternal work and maternity leave

does not work

48.3 (43.8–52.8)

51.4 (44.4–58.4)

57.4 (43.2–70.8)

47.7 (41.9–53.5)

48.2 (40.4–56.1)

65.5 (51.9–77.5)

54.0 (45.3–62.6)

42.4 (36.0–49.1)

59.3 (48.5–69.5)

works from home

4.8 (3.1–7.1)

5.3 (2.7–9.3)

3.7 (0.5–12.7)

4.0 (2.1–6.8)

9.0 (5.1–14.5)

0.0 (0.0–6.2)

4.4 (1.6–9.3)

6.1 (3.4–10.0)

3.3 (0.7–9.3)

ML up to 6 mos

6.1 (4.1–8.5)

3.8 (1.7–7.4)

3.7 (0.5–12.7)

7.3 (4.6–10.8)

4.2 (1.7–8.5)

5.2 (1.1–14.4)

8.0 (4.1–13.9)

6.1 (3.4–10.0)

2.2 (0.3–7.7)

ML up to 4 mos

29.1 (25.1–33.3)

27.4 (21.5–34.0)

16.7 (7.9–29.3)

27.8 (22.8–33.2)

25.9 (19.4–33.3)

24.1 (13.9–37.2)

19.0 (12.8–26.6)

33.3 (27.3–39.8)

23.1 (14.9–33.1)

works without ML benefits

11.7 (9.0–14.9)

12.0 (7.9–17.2)

18.5 (9.3–31.4)

13.2 (9.6–17.6)

12.7 (8.0–18.7)

5.2 (1.1–14.4)

14.6 (9.2–21.6)

12.1 (8.2–17.0)

12.1 (6.2–20.6)

 Mode of delivery

cesarean

52.7 (48.2–57.2)

74.0 (67.5–79.9)

81.5 (68.6–90.7)

53.0 (47.2–58.7)

66.3 (58.5–73.4)

74.1 (61.0–84.7)

51.1 (42.4–59.7)

55.4 (48.8–61.9)

70.3 (59.8–79.5)

transpelvic

47.3 (42.8–51.8)

26.0 (20.1–32.5)

18.5 (9.3–31.4)

47.0 (41.3–52.8)

33.7 (26.6–41.5)

25.9 (15.3–39.0)

48.9 (40.3–57.6)

44.6 (38.1–51.2)

29.7 (20.5–40.2)

 Use of a pacifier

no

93.7 (91.2–95.7)

77.9 (71.6–83.3)

35.2 (22.7–49.4)

92.7 (89.2–95.4)

84.3 (77.9–89.5)

69.0 (55.5–80.5)

94.9 (89.8–97.9)

89.2 (84.4–92.9)

67.0 (56.4–76.5)

yes

6.3 (4.3–8.8)

22.1 (16.7–28.4)

64.8 (50.6–77.3)

7.3 (4.6–10.8)

15.7 (10.5–22.1)

31.0 (19.5–44.5)

5.1 (2.1–10.2)

10.8 (7.1–15.6)

33.0 (23.5–43.6)

 Skin-to-skin contact in the delivery room

yes

55.6 (51.1–60.0)

34.6 (28.2–41.5)

5.6 (1.2–15.4)

54.0 (48.2–59.7)

44.6 (36.9–52.5)

32.8 (21.0–46.3)

56.2 (47.5–64.7)

51.5 (44.9–58.1)

34.1 (24.5–44.7)

no

44.4 (40.0–48.9)

65.4 (58.5–71.8)

94.4 (84.6–98.8)

46.0 (40.3–51.8)

55.4 (47.5–63.1)

67.2 (53.7–79.0)

43.8 (35.3–52.5)

48.5 (41.9–55.1)

65.9 (55.3–75.5)

 BF difficulties

no

44.6 (40.2–49.1)

38.5 (31.8–45.4)

7.4 (2.1–17.9)

46.0 (40.3–51.8)

39.2 (31.7–47.0)

20.7 (11.2–33.4)

48.9 (40.3–57.6)

44.6 (38.1–51.2)

28.6 (19.6–39.0)

yes

55.4 (50.9–59.8)

61.5 (54.6–68.2)

92.6 (82.1–97.9)

54.0 (48.2–59.7)

60.8 (53.0–68.3)

79.3 (66.6–88.8)

51.1 (42.4–59.7)

55.4 (48.8–61.9)

71.4 (61.0–80.4)

 Use of pasteurized donor human milk

no

44.0 (39.6–48.5)

50.0 (43.0–57.0)

1.9 (0.0–9.9)

51.7 (45.9–57.4)

31.9 (24.9–39.6)

24.1 (13.9–37.2)

56.2 (47.5–64.7)

47.2 (40.6–53.8)

25.3 (16.7–35.5)

yes

56.0 (51.5–60.4)

50.0 (43.0–57.0)

98.1 (90.1–100.0)

48.3 (42.6–54.1)

68.1 (60.4–75.1)

75.9 (62.8–86.1)

43.8 (35.3–52.5)

52.8 (46.2–59.4)

74.7 (64.5–83.3)

 Use of cup-feeding

no

44.2 (39.8–48.7)

13.0 (8.7–18.3)

53.7 (39.6–67.4)

36.4 (31.0–42.1)

27.1 (20.5–34.5)

27.6 (16.7–40.9)

39.4 (31.2–48.1)

35.1 (28.9–41.6)

38.5 (28.4–49.2)

yes

55.8 (51.3–60.2)

87.0 (81.7–91.3)

46.3 (32.6–60.4)

63.6 (57.9–69.0)

72.9 (65.5–79.5)

72.4 (59.1–83.3)

60.6 (51.9–68.8)

64.9 (58.4–71.1)

61.5 (50.8–71.6)

 NB received infant formula

no

96.8 (94.8–98.1)

3.8 (1.7–7.4)

0.0 (0.0–6.6)

76.2 (70.9–80.9)

60.8 (53.0–68.3)

43.1 (30.2–56.8)

73.7 (65.5–80.9)

71.4 (65.1–77.2)

42.9 (32.5–53.7)

yes

3.2 (1.9–5.2)

96.2 (92.6–98.3)

100.0 (93.4–100.0)

23.8 (19.1–29.1)

39.2 (31.7–47.0)

56.9 (43.2–69.8)

26.3 (19.1–34.5)

28.6 (22.8–34.9)

57.1 (46.3–67.5)

 Place admission

maternity ward

82.2 (78.6–85.5)

57.2 (50.2–64.0)

0.0 (0.0–6.6)

81.5 (76.6–85.7)

66.3 (58.5–73.4)

48.3 (35.0–61.8)

81.0 (73.4–87.2)

77.9 (72.0–83.1)

46.2 (35.6–56.9)

NICU

17.8 (14.5–21.4)

42.8 (36.0–49.8)

100.0 (93.4–100.0)

18.5 (14.3–23.4)

33.7 (26.6–41.5)

51.7 (38.2–65.0)

19.0 (12.8–26.6)

22.1 (16.9–28.0)

53.8 (43.1–64.4)

 Feeding practice at hospital discharge

EBF

–

–

–

75.8 (70.6–80.5)

62.7 (54.8–70.0)

43.1 (30.2–56.8)

72.3 (64.0–79.6)

73.2 (67.0–78.8)

44.0 (33.6–54.8)

PBF

–

–

–

23.2 (18.5–28.4)

32.5 (25.5–40.2)

36.2 (24.0–49.9)

26.3 (19.1–34.5)

24.2 (18.9–30.3)

35.2 (25.4–45.9)

NBF

–

–

–

1.0 (0.2–2.9)

4.8 (2.1–9.3)

20.7 (11.2–33.4)

1.5 (0.2–5.2)

2.6 (1.0–5.6)

20.9 (13.1–30.7)