Use of Antiasthmatic Drugs during Pregnancy after the First Trimester and Maternal and Neonatal Outcomes

Abstract

Background. Women with asthma using antiasthmatics during the later part of the pregnancy have an increased risk for obstetric complications and their infants of neonatal complications. Material and Methods. The study is based on a linkage between the Swedish Medical Birth Register and a register of prescribed drugs in Sweden for the years 2009-2011, identifying women who had filled prescriptions for antiasthmatics after the first trimester. Their characteristics, their obstetric history, and the neonatal conditions of their infants were compared with all other women who gave birth. Adjusted Mantel-Haenszel odds ratios were determined. Results. We found an increased risk for a number of maternal conditions but no risk increase for gestational diabetes (after adjustment for body mass index) or for premature rupture of membranes. There was an increase in preterm births for some drugs used at severe asthma and of low birth weight and small for gestational age for most drug combinations. An increased risk was seen for neonatal hypoglycemia, respiratory problems, and low Apgar score. Conclusions. There are many hazards associated with maternal asthma and use of antiasthmatic drugs. Most evidence suggests a disease effect. A careful control of the asthma during pregnancy is important.