Table 1.

The incidence of emergency room visits or hospitalisation for asthma exacerbations during pregnancy

	Number of patients with events (%)	Number of events	Incidence (per pregnancy)
Definition 1: Among all pregnant women with asthma
In the complete study period (n=5589; 0.43% among all pregnant women)
(1) ER visit or hospitalisation for asthma treatment	647 (11.6%)	926	0.17
(2) Condition 1+treatment with systemic steroids or SABA	383 (6.9%)	506	0.09
In 2009 (n=1986; 0.44% of all pregnant women)
(1) ER visit or hospitalisation due to asthma	223 (11.2%)	324	0.16
(2) Condition 1+treatment with systemic steroids or SABA	127 (6.4%)	170	0.09
In 2010 (n=1864; 0.41% of all pregnant women)
(1) ER visit or hospitalisation for asthma treatment	213 (11.4%)	318	0.16
(2) Condition 1+treatment with systemic steroids or SABA	132 (7.1%)	184	0.09
Definition 2: Definition 1 and treatment with antiasthmatic drugs
In the complete study period (n=3825; 0.29% of all pregnant women)
(1) ER visit or hospitalisation due to asthma	613 (16%)	886	0.23
(2) Condition 1+treatment with systemic steroids or SABA	383 (10%)	506	0.13
In 2009 (n=1325; 0.29% of all pregnant women)
(1) ER visit or hospitalisation for asthma treatment	213 (16.1%)	313	0.24
(2) Condition 1+treatment with systemic steroids or SABA	127 (9.6%)	170	0.13
In 2010 (n=1274; 0.28% of all pregnant women)
(1) ER visit or hospitalisation due to asthma	201 (15.8%)	305	0.23
(2) Condition 1+treatment with systemic steroids or SABA	132 (10.4%)	184	0.14

ER, emergency room; SABA, short-acting β2-agonists.