Table 4 Adjusted^a odds ratios (OR) with 95 % confidence intervals (95 % CI) for prematurity-related adverse outcomes by male sex at birth in gestational week 35–36, and cohort ratios (CR) for the change in male risk before and after the implementation of ultrasound for pregnancy dating in Sweden

Neonatal death

1.15 (0.91–1.45)

0.95 (0.71–1.26)

0.82 (0.57–1.19)

Apgar score <7 at 5 min

1.08 (0.91–1.28)

1.26 (1.10–1.45)

1.17 (0.94–1.45)

Pneumothorax

1.70 (1.10–2.62)

2.27 (1.66–3.11)

1.34 (0.78–2.28)

RDS^c

1.74 (1.40–2.16)

1.89 (1.56–2.28)

1.08 (0.81–1.45)

Other respiratory conditions

1.31 (1.12–1.54)

1.60 (1.48–1.72)

1.22 (1.02–1.45)

Hyperbilirubinemia

1.12 (1.03–1.20)

1.18 (1.12–1.23)

1.05 (0.96–1.15)