A sthma complicated 4% to 8% of all pregnancies nearly 10 years ago and its rate continues to increase. Recent studies concluded that asthma increases the risk of low birthweight, small for gestational age, preterm delivery, and preeclampsia and that outcomes are generally worse when asthma is poorly controlled. The purpose of this study was to examine specific risks for complications of pregnancy, labor, and delivery among a large cohort of women in the United States to explore less frequent outcomes and the reasons for the increased risk of preterm delivery in women with asthma. Asthma complicated 7.6% of pregnancies included in this study and mothers with asthma were younger (P < 0.0001) and more likely to be non-Hispanic black, unmarried, and have public insurance. Those with asthma were more likely to be obese before pregnancy, smoke (P < 0.0001), and consume alcohol (P < 0.0001) during pregnancy. Pregnancies complicated by asthma were also more likely to be burdened by other chronic diseases (P < 0.0001). Superimposed preeclampsia [adjusted odds ratio (aOR) 1.354; 95% confidence interval (CI), 1.1533-156.79] and preeclampsia (aOR 1.124; 95% CI, 1.016-1.2233) were significantly associated with asthma in site-adjusted models, but were attenuated after full adjustment (aOR 1.4134; 95% CI, 0.961.15-2.071.56 for preeclampsia, aOR 1.14; 95%CI, 1.06-1.22 for preeclampsia). Increased risk of gestational diabetes (aOR 1.11; 95% CI, 1.03-1.19) and placenta previa (aOR 1.3; 95% CI, 1.08-1.56) was associated with asthma. Asthmatic pregnancies were more likely to be scheduled for prelabor or cesarean delivery (aOR 1.16; 95% CI, 1.09-1.23) or induction (aOR 1.10; 95% CI, 1.06-1.14); asthmatic women were more likely to have a cesarean section regardless of spontaneous labor presentation (P = 0.0003) or labor induction (P < 0.0001). Preterm premature rupture of membranes was higher in deliveries with asthma (P < 0.0001). Placental abruption (aOR 1.22; 95% CI, 1.09-1.36), hemorrhage (aOR 1.09; 95% CI, 1.03-1.16), pulmonary embolism (aOR 1.71; 95% CI, 1.05-2.79), and maternal ICU admission (aOR 1.34; 95% CI, 1.04-1.72) were significantly increased in cases of maternal asthma. Low birthweight (aOR 1.16; 95% CI, 1.10-1.23) and preterm delivery (aOR 1.17; 95% CI, 1.12-1.23) were both associated with maternal asthma, but intrauterine fetal death was not. No r 2014 Lippincott Williams & Wilkins www.obstetricanesthesia.com | 15 2. Centers for Disease Control and Prevention. National Center for Health Statistics. Asthma and chronic obstructive pulmonary disease: US. 1997-2011. Available at: http://205.207.175.93/HDI/TableViewer/tableView.aspx?Report Id = 60. Accessed November 29, 2013. 3. Enriquez R, Griffin MR, Carroll KN, et al. Effect of maternal asthma and asthma control on pregnancy and perinatal outcomes. J Allergy Clin Immunol. 2007;120:625-630. 4. Schatz M, Dombrowski MP, Wise R, et al. Spirometry is related to perinatal outcomes in pregnant women with asthma.
