Use of Inhaled Corticosteroids During Pregnancy and Risk of Pregnancy-Induced Hypertension: Nested Case???Control Study

Abstract

An estimated 6% to 8% women develop hypertension during pregnancy, which has been linked with asthma, through either the condition itself or treatment such as oral corticosteroids. Steroid use also has been linked with an increased risk of preeclampsia. This large population-based case–control study was planned to determine whether inhaled steroids increase the risk of either pregnancy-induced hypertension or preeclampsia in asthmatic women. Participants were 3505 women with asthma, 14–44 years of age, who had 4593 pregnancies in the years 1990–2000. As many as 10 control women at 30 or more weeks gestation were selected for each case. Sociodemographic factors were similar in the case and control groups. There were 302 cases of pregnancy-induced hypertension, representing 6.6% of the study population. They included 128 cases of gestational hypertension, 165 cases of preeclampsia, and 9 cases of eclampsia. More case women than controls were prescribed inhaled corticosteroids before and during pregnancy, and more were taking oral steroids. Case women who took more than 3 doses of a short-acting β2 agonist per week before pregnancy were at increased risk of pregnancy-induced hypertension, but this level of treatment during pregnancy correlated with a lower risk. Cases more often visited an emergency department for asthma. Using inhaled steroids while pregnant was not associated with the risk of either preeclampsia or pregnancy-induced hypertension. There was no dose–response relationship with inhaled steroids for either of these conditions. Oral steroids were, however, significantly associated with pregnancy-induced hypertension; the adjusted odds ratio was 1.57, and the 95% confidence interval was 1.02–2.41. This study failed to significantly relate the use of inhaled corticosteroids to either pregnancy-induced hypertension or preeclampsia in asthmatic women. These women should be encouraged to continue using inhaled steroids while pregnant to control their asthma.