Table 2

Summary of studies investigating the association between asthma exacerbations and perinatal outcomes

Study	Country	Year	Study design	Control (n)	Asthma (n)	Exacerbations (n)	Adverse perinatal outcomes associated with exacerbations
ED, emergency department, PIH, pregnancy induced hypertension.
Gordon et al²⁶	USA		Historical cohort	n = 30861 (all)	n = 277	n = 16 (recurrent attacks or status asthmaticus)	Fetal death
Greenberger and Patterson²⁷	USA	1981–7	Case series		n = 80	n = 25 (emergency treatment or status asthmaticus)	Reduced birth weight (status asthmaticus v no status asthmaticus)
Stenius-Aarniala et al⁶	Finland	1978–82	Prospective cohort	n = 198	n = 198	n = 90 (acute worsening requiring medical attention) n = 34 (hospitalisation)	Mild pre-eclampsia (hospitalisation group v women with mild asthma without exacerbations during pregnancy)
Schatz et al²⁸	USA	1978–84	Prospective cohort		n = 360	Number unknown (acute episodes of asthma requiring emergency treatment or hospitalisation)	Lower mean birth weight by 273 g (not statistically significant).
Schatz et al¹²	USA	1978–89	Prospective cohort	n = 486	n = 486	n = 54 (emergency treatment)	None significant (pre-eclampsia, low birth weight, preterm delivery)
Jana et al¹¹	India	1983–92	Prospective cohort	n = 364	n = 182	n = 15 (hospitalisation)	Low birth weight (women who were hospitalised compared with asthmatics who were not hospitalised)
Stenius-Aarniala et al¹³	Finland	1982–92	Prospective and retrospective cohort	n = 237	n = 504	n = 47 (asthma not controlled by usual rescue medications and treated as emergency)	None significant (pre-eclampsia, premature rupture of membranes, gestational diabetes, preterm delivery, perinatal death, emergency caesarean section)
Sobande et al²⁹	Saudi Arabia	1997–2000	Prospective cohort	n = 106	n = 88	n = 62 (ED presentation)	Reduced birth weight Reduced placental weight
							Pre-eclampsia (entire asthma group compared to the control group)
Martel et al¹⁹	Canada	1990–2000	Case control		n = 4593 pregnancies in 3505 women	n = 1553 (used oral steroids)	Oral steroid use significantly associated with PIH
Martel et al¹⁹	Canada	1990–2000	Case control		n = 4593 pregnancies in 3505 women	n = 430 (admission or ED visit for asthma)	Admissions or ED visits during pregnancy not associated with PIH or pre-eclampsia
Bakhireva et al²¹	North America	1998–2003	Prospective cohort	n = 303	n = 654	n = 16 (hospitalisation), n = 62 unscheduled clinic visits (first trimester), n = 48 unscheduled clinic visits (third trimester)	Among users of oral steroids, hospital admissions, or unscheduled clinic visits were not associated with birth weight
Murphy et al²⁴	Australia	1997–2003	Prospective cohort		n = 146	n = 53 (hospitalisation or ED presentation or unscheduled doctor visit or course of oral steroids)	Reduced birth weight among male neonates (compared to women with no exacerbation)