Improvement in Airway Responsiveness and Asthma Severity during Pregnancy: A Prospective Study

In the myometrium and gut, smooth muscle becomes less contractile during pregnancy, probably because of the effect of progesterone and estrogen. It is not known whether these hormones cause similar changes in airway smooth muscle, and therefore, this study examined airway responsiveness during the large hormonal changes of pregnancy and evaluated whether changes in responsiveness are associated with changes in (1) progesterone and estrogen and …