DENVER – Obesity and weight gain of more than 5 kg during the first trimester in women with asthma are significant predictors of asthma exacerbation during pregnancy, according to findings from the Management of Asthma during Pregnancy (MAP) study.
Of 1,018 women in the prospective study, 370 experienced a total of 407 asthma exacerbations. The risk of exacerbation was greatest in those with body mass index over 30 kg/m2 (odds ratio, 2.2) and in those with gestational weight gain of more than 5 kg in the first trimester (OR, 8.2), Zarqa Ali of Hvidovre Hospital, Copenhagen, and colleagues reported in a poster at an international conference of the American Thoracic Society.
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Other risk factors for exacerbation included previous asthma exacerbations (OR, 1.3), uncontrolled asthma (OR, 2), inhaled corticosteroid treatment (OR, 5.8), and current and former smoking (OR, 1.9), the investigators said.
Risk factors for severe exacerbation of asthma, which occurred in 157 women, included gestational weight gain of greater than 5 kg (OR, 4.1), and age (OR, 1.1).
After excluding women with a prepregnancy body mass index above the mean of 24.1, risk factors for exacerbation included first-trimester weight gain greater than 5 kg (OR, 13.1) and lower prepregnancy body weight (OR, 0.9), they noted.
Women included in the study had a diagnosis of asthma, had been prescribed rescue bronchodilator therapy, had their first outpatient clinic visit within the first 18 weeks of pregnancy, and were seen for scheduled visits about every 4 weeks during pregnancy and for 3 months post partum. The women had a mean age of 31 years, 73% had never smoked, and their mean forced expiratory volume in 1 second (FEV1) % predicted was 92, and mean exhaled nitric oxide was 20 ppb.
FEV1% predicted was significantly greater at baseline in those without exacerbations vs. with exacerbations (93 vs. 90), and exhaled nitric oxide was significantly lower in the groups, respectively (18 vs. 23 ppb).
The findings are important, as acute exacerbations of asthma during pregnancy may be the most significant risk factor for unfavorable pregnancy outcomes in women with asthma, the investigators said, noting that exacerbations occur in about 30% of pregnant women with asthma and are associated with complications such as preterm delivery, low birth weight, excessive antepartum hemorrhage, and cesarean delivery.
Risk factors for exacerbation identified in prior studies include severe asthma, viral infections, nonadherence to controller medication, tobacco exposure, and possibly fetal gender and maternal body mass index, the investigators said.
The investigators reported having no disclosures.