Table 1

Maternal information

Maternal information Boys
(n=3356)
Girls
(n=3382)
OR (boys/girls)
(95% CI)
Married34  (14–67)33  (13–68)1.05 (0.95 to 1.17)
⩽18 years of age10 (4–14)9 (5–15)1.07 (0.91 to 1.27)
⩾35 years of age8 (5–9)8 (3–20)0.96 (0.80 to 1.15)
Prenatal care1-150 86 (80–98)87 (81–96)0.94 (0.82 to 1.09)
Antepartum haemorrhage17 (4–31)14 (1–26)1.31 (1.14 to 1.50)
Antenatal steroids20 (1–35)24 (1–43)0.80 (0.71 to 0.90)
Antenatal antibiotics33 (20–43)34 (22–45)0.98 (0.88 to 1.09)
Race
 Black54 (6–87)55 (7–87)0.94 (0.85 to 1.04)
 White31 (11–66)31 (11–73)
 Hispanic13 (0–48)11 (0–45)
 Other2 (0–18)2 (0–16)
ROM ⩾1 hour51 (38–59)54 (38–61)0.88 (0.88 to 0.98)
ROM ⩾24 hours26 (18–33)27 (22–37)0.96 (0.85 to 1.07)
  • Based on 6186 mothers; inborn infants born between 1 May 1991 and 31 December 1993 with birth weights from 501 to 1500 g. Data are presented as percentages with centre ranges in parentheses.

  • 1-150 Defined as at least one prenatal visit.

  • ROM, Rupture of membranes.