Table 2.

Adjusted odds ratios (aOR) for admission to hospital with asthma between 2 and 5 yrs of age (simultaneous adjustment for all listed factors in the entire table)

	aOR of asthma admission (95% CI)
Maternal and environmental factors
Maternal asthma admission*	2.09 (1.90–2.29)
Maternal age <20 yrs	1.20 (1.07–1.34)
Maternal age ≥35 yrs	1.00 (0.94–1.07)
Nulliparous (first child)	0.97 (0.92–1.02)
Smoked during pregnancy	1.08 (1.02–1.15)
Urban area resident	1.18 (1.10–1.26)
Most advantaged socio-economic quintile	0.87 (0.80–0.95)
2nd advantaged socio-economic quintile	0.92 (0.86–0.99)
Pregnancy and delivery factors
Spring conception	1.03 (0.96–1.10)
Autumn conception	1.09 (1.02–1.16)
Winter conception	1.15 (1.08–1.23)
Antenatal admit UTI†	1.49 (1.23–1.79)
Any maternal diabetes	0.95 (0.86–1.06)
Any maternal hypertension	1.02 (0.95–1.11)
Pre-term PROM‡	1.23 (1.04–1.45)
Term PROM‡	1.06 (0.97–1.16)
Induction with prostaglandins	1.05 (0.97–1.13)
Cesarean section delivery	1.03 (0.97–1.09)
Infant factors
Male	1.70 (1.62–1.79)
Gestational age (per additional week)	0.947 (0.93–0.96)
SGA (<10th percentile size)	1.08 (1.00–1.17)
LGA (>10th percentile size)	0.97 (0.89–1.05)
Respiratory distress syndrome	1.34 (1.12–1.60)
Transient tachypnea of newborn	1.20 (1.07–1.36)
Jaundice and/or phototherapy	1.10 (0.99–1.22)
Neonatal bacterial sepsis	1.20 (0.90–1.60)

LGA, large-for-gestational-age; PROM, pre-labor rupture of membranes; SGA, small-for-gestational-age.

^*Mother was admitted with asthma anytime between July 2000 and June 2009.

^†Urinary tract infection

^‡Spontaneous pre-labor rupture of membranes.