Asthma doesn't usually increase pregnancy risks

Adverse obstetric or pediatric complications are not generally increased in women with asthma, according to a report in the May 15th American Journal of Respiratory and Critical Care Medicine.

Previous studies have suggested the possibility of increased risks of pregnancy complications in women with asthma, the authors explain, but these studies have had various statistical shortcomings.

To further investigate, Dr. Laila J. Tata from University of Nottingham in the UK and colleagues used data from more than 280,000 pregnancies to compare the risks of obstetric complications and adverse pregnancy outcomes in women with asthma and those without asthma.
Asthma did not significantly increase the risk of high blood pressure, diabetes, thyroid disorders, the need for assisted delivery, placental separation from the uterine wall (placental abruption), placenta blocks the opening to the birth canal (placental previa), pre-eclampsia (a condition affecting multiple body systems characterized by high blood pressure and kidney failure), or eclampsia (progression of pre-eclampsia to a life-threatening severity).

However, when compared with women without asthma, women with asthma did have a 20-percent increased risk of hemorrhaging during delivery, a 38-percent risk of hemorrhaging after delivery, a 6-percent risk of anemia, and a 57-percent increase risk of depression. They were also 11-percent more likely to deliver by cesarean section.

Women with more severe asthma and a history of asthma exacerbations had an increased risk of miscarriage and depression, the researchers note, but increased risk of hemorrhage after delivery was restricted to women with milder asthma and no exacerbations.

"Our results provide reassuring evidence that the risks of most adverse pregnancy outcomes and obstetric complications are similar to those in women without asthma," the investigators conclude.

"With the possible exception of increased vigilance in monitoring certain complications in pregnant women with asthma, our findings do not indicate a necessity to alter current practice of optimal (asthma drug therapy) in women of child-bearing age in the general population," the authors add.

SOURCE: American Journal of Respiratory and Critical Care Medicine, May 15, 2007.