Table 2

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

StudyCountryYearStudy designControl (n)Asthma (n)Exacerbations (n)Adverse perinatal outcomes associated with exacerbations
ED, emergency department, PIH, pregnancy induced hypertension.
Gordon et al26USAHistorical cohortn = 30861 (all)n = 277n = 16 (recurrent attacks or status asthmaticus)Fetal death
Greenberger and Patterson27USA1981–7Case seriesn = 80n = 25 (emergency treatment or status asthmaticus)Reduced birth weight (status asthmaticus v no status asthmaticus)
Stenius-Aarniala et al6Finland1978–82Prospective cohortn = 198n = 198n = 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 al28USA1978–84Prospective cohortn = 360Number unknown (acute episodes of asthma requiring emergency treatment or hospitalisation)Lower mean birth weight by 273 g (not statistically significant).
Schatz et al12USA1978–89Prospective cohortn = 486n = 486n = 54 (emergency treatment)None significant (pre-eclampsia, low birth weight, preterm delivery)
Jana et al11India1983–92Prospective cohortn = 364n = 182n = 15 (hospitalisation)Low birth weight (women who were hospitalised compared with asthmatics who were not hospitalised)
Stenius-Aarniala et al13Finland1982–92Prospective and retrospective cohortn = 237n = 504n = 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 al29Saudi Arabia1997–2000Prospective cohortn = 106n = 88n = 62 (ED presentation)Reduced birth weight Reduced placental weight
Pre-eclampsia (entire asthma group compared to the control group)
Martel et al19Canada1990–2000Case controln = 4593 pregnancies in 3505 womenn = 1553 (used oral steroids)Oral steroid use significantly associated with PIH
n = 430 (admission or ED visit for asthma)Admissions or ED visits during pregnancy not associated with PIH or pre-eclampsia
Bakhireva et al21North America1998–2003Prospective cohortn = 303n = 654n = 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 al24Australia1997–2003Prospective cohortn = 146n = 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)