Table 5 Relative risks estimates (hazard ratios) of hospitalization for bronchiolitis in 33^+0d-34^+6d wGA newborns

  Prenatal Conditions

Assisted reproductive technology

0.3 (0.1-0.8)

Prenatal smoke exposure

1.9 (1.1-3.3)

2.0 (1.2-3.5)

  Neonatal Conditions

Male gender

1.6 (1.1-2.3)

1.6 (1.0-2.7)

Singleton

1.7 (1.1-3.0)

Apgar in the first 5 min <8

2.2 (1.1-4.9)

Birth weight in g

1.0 (1.0-1.0)

Surfactant therapy

3.8 (2.0-7.4)

3.1 (1.6-6.0)

Antibiotic therapy

2.0 (1.1-3.5)

  Postnatal Conditions

Presence of siblings ≤10 year

3.8 (2.1-6.6)

3.2 (1.8-5.7)

Residential crowding

3.0 (1.7-5.5)

2.9 (1.6-5.4)

Indoor humidity

1.9 (1.1-3.8)

Exposure to epidemic season

1.8 (1.0-3.0)

1.8 (1.0-3.3)