Table 5 Rates of respiratory distress syndrome (RDS) at 32–36 weeks and 37–38 weeks per 1000 fetuses at risk and unadjusted odds ratios and 95 % confidence intervals (CI) expressing the association between maternal and infant characteristics and RDS, United States, 2005–2006

Age

<20 years

1165

426,327

2.7

1.00 [0.94, 1.06]

360

386,323

0.93

0.83 [0.74, 0.92]

20–34

8969

3,265,775

2.7

Reference

3364

2,978,793

1.13

Reference

≥35

1808

610,342

3.0

1.03 [1.01, 1.04]

568

545,748

1.04

0.97 [0.95, 1.00]

2770

133,526

20.7

9.61 [9.21, 10.0]

214

55,869

3.83

3.63 [3.16, 4.17]

1613

441,604

3.7

1.37 [1.30, 1.44]

632

392,595

1.61

1.55 [1.42, 1.69]

996

160,801

6.2

2.35 [2.20, 2.51]

414

136,882

3.02

2.95 [2.67, 3.27]

423

44,759

9.5

3.52 [3.19, 3.88]

126

35,036

3.60

3.35 [2.81, 4.01]

832

61,034

13.6

5.26 [4.90, 5.65]

346

50,707

6.82

6.71 [6.01, 7.50]

7130

2,200,877

3.2

1.42 [1.37, 1.47]

2739

1,994,128

1.37

1.70 [1.59, 1.81]

11,942

4,302,444

2.8

-

4292

3,910,864

1.10

-