Question 2. How does maternal asthma affect pregnancy outcome?

From Chapter 8 of the Philippine Consensus Report on Asthma 2004 by the Philippine College of Chest Physicians.
This guideline starts below.

How does maternal asthma affect pregnancy outcome?

Answer

When asthma is properly controlled, pregnant women with asthma can maintain a normal pregnancy with little or no increased risk to themselves or their fetuses.

Summary of Evidence

Uncontrolled asthma during pregnancy has been proven to produce serious maternal and fetal complications. Both mother and child are at risk if asthma is not well managed during pregnancy. Severe persistent asthma has been related to the development of maternal complications like pre-eclampsia, maternal hypertension, hyperemesis gravidarum, uterine vaginal hemorrhage, toxemia, placenta previa, and induced complicated labors. Fetal complications include increased risk of perinatal mortality, intrauterine growth retardation, preterm birth, low birth weight, and neonatal hypoxia.

Studies in which asthma was actively controlled did not show any difference in the overall incidence of adverse fatal outcomes among infants of asthmatic women and non-asthmatic women. A study involving severe asthma reported that pregnant women with poorly controlled asthma requiring hospital admission gave birth to infants who weighed significantly less than babies whose mothers' asthma is well controlled. Severe asthma requiring emergency therapy or corticosteroid seem to be associated with an increased incidence of perinatal complications like pre-eclampsia, low-birth weight infants, perinatal mortality, preterm births and hyperbilirubinemia. However, these associations did not reach statistical significance.