Table 1 Preterm live births and RDS-associated neonatal deaths demographic characteristics, São Paulo state, Brazil, 2004–2015 

Maternal age (years)

n = 645,253

n = 11,078

 < 20

109,089 (16.9)

2,504 (22.6)

 20–34

433,067 (67.1)

7,161 (64.6)

 ≥ 35

103,097 (16.0)

1,413 (12.8)

Maternal schooling (years)

n = 504,995

n = 9,305

 ≤ 7

126,382 (25.0)

2,850 (30.6)

Primiparous

n = 487,941

n = 9,485

 Yes

213,787 (43.8)

4,276 (45.1)

Prenatal care visits

n = 633,801

n = 10,693

 ≥ 4

556,029 (87.7)

6,793 (63.5)

Multiple pregnancy

n = 645,110

n = 11,078

 No

556,993 (86.3)

9,209 (83.1)

Delivery

n = 644,905

n = 11,075

 C-section

388,302 (60.2)

4,707 (42.5)

Gestational age

n = 645,276

n = 11,078

 22^0/7–27^6/7 weeks

32,987 (5.1)

6,779 (61.2)

 28^0/7–31^6/7 weeks

63,106 (9.8)

3,032 (27.4)

 32^0/7–36^6/7 weeks

549,183 (85.1)

1,267 (11.4)

Sex

n = 645,276

n = 11,078

 Male

340,101 (52.7)

6,336 (57.2)

Birthweight

n = 645,276

n = 11,078

 < 1500 g

85,898 (13.3)

9,906 (89.6)

 5^th minute Apgar score

n = 504,569

n = 8,775

 ≥ 7

482,122 (95.6)

5,211 (59.4)