ASSOCIATION BETWEEN PREGNANCY-INDUCED HYPERTENSION AND ASTHMA DURING PREGNANCY

OBJECTIVE: Pregnancy-induced hypertension is an important cause of mat ernal mortality, intrauterine growth retardation, and perinatal mortal ity. We examined the relationship between pregnancy-induced hypertensi on and asthma. STUDY DESIGN: The study population consisted of 24,115 women without a history of chronic systemic hypertension who were deli vered of live born and stillborn infants at Mount Sinai Medical Center between January 1987 and December 1991. Pregnancy-induced hypertensio n was defined as blood pressure of at least 140/90 mm Hg or an increas e of greater-than-or-equal-to 30 mm Hg in systolic pressure or greater -than-or-equal-to 15 mm Hg in diastolic pressure. RESULTS: There was a significant association between pregnancy-induced hypertension and as thma during pregnancy (chi2 = 17.86, p < 0.001). In addition, there wa s a significant upward trend in the incidence of asthma during pregnan cy in women without, with moderate, and with severe pregnancy-induced hypertension (Mantel-Haenszel chi2 = 11.8, p = 0.001). Logistic regres sion analysis demonstrated that the association between pregnancy-indu ced hypertension and asthma during pregnancy persisted after adjustmen t for the confounding factors of race or ethnicity, maternal age, pari ty, and prepregnancy weight (adjusted odds ratio 2.52, 95% confidence interval 1.47 to 4.35, p = 0.0008). An association between pregnancy-i nduced hypertension and a history of asthma was also found (chi2 = 11. 2, p = 0.001). However, after adjustment for potential confounders, th is association failed to achieve statistical significance (adjusted od ds ratio 1.2, 95% confidence interval 0.97 to 1.53, p = 0.083). CONCLU SION: Both pregnancy-induced hypertension and asthma might be caused b y a third factor affecting smooth muscle reactivity.