Asthma in pregnancy - from immunology to clinical management

Maternal asthma is associated with increased risk of perinatal mortality

Background

Asthma is the most common chronic disease during pregnancy and it may have influence on pregnancy outcome.

Objectives

Our goal was to assess the association between maternal asthma and the perinatal risks as well as possible effects of asthma medication.

Methods

The study was based on a nationwide Finnish register-based cohort between the years 1996 and 2012 in the Drug and Pregnancy Database. The register data comprised 962 405 singleton live and stillbirths, 898 333 (93.3%) pregnancies in mothers with neither confirmed asthma nor use of asthma medication (controls), and 26 674 (2.8%) pregnancies with confirmed maternal asthma. 71% of mothers with asthma used asthma medication. The diagnosis of asthma was based on the mothers’ right for subsidised medication which is carefully evaluated by strict criteria including pulmonary function testing. Odds ratio was used in comparison. Premature birth (PB), low birth weight, small for gestational age (SGA), neonatal death were the main outcome measures.

Results

Maternal asthma was associated with adjusted odds ratios (aORs) for perinatal mortality 1.24 (95% CI 1.05 to 1.46), preterm birth 1.18 (1.11 to 1.25), low birth weight 1.29 (1.21 to 1.37), fetal growth restriction (SGA) 1.32, (1.24 to 1.40), and asphyxia 1.09 (1.02 to 1.17). Asthma treatment reduced the increased risk of preterm birth aOR 0.85 (95% CI 0.76 to 0.96) but mothers with treated asthma had higher risks of fetal growth restriction (SGA) aOR 1.26 (1.10 to 1.45), and asphyxia aOR 1.37 (1.17 to 1.61) than mothers with untreated asthma.

Conclusion

Asthma is associated with increased risks of perinatal mortality, preterm birth, low birth weight, fetal growth restriction (SGA), and asphyxia. Asthma treatment reduces the risk of preterm delivery, but it does not seem to reduce other complications such as perinatal mortality.

Does drug compliance change in asthmatic patients during pregnancy?

Background

Pregnant women with asthma are recommended to maintain optimal therapeutic management during pregnancy. Uncontrolled, symptomatic asthma may increase the risk of adverse peri-natal outcomes; thus adequate regular anti-asthmatic treatment must be given to provide optimal asthma control during pregnancy. However, doubts about the safety of asthmatic drugs can affect pregnant asthmatic patients’ drug compliance. The aim of this study was to assess behavioral differences in drug compliance among pregnant asthmatic patients.

Methods

Thirty two asthmatic and 121 healthy pregnant women were enrolled in the study. Structured face-to-face interviews were conducted after delivery. The interviews included disease characteristics, drug compliance and patients’ own perspective for asthma status prior to and during pregnancy. In addition, medical and pregnancy history, pregnancy complications and outcomes, and newborn characteristics were recorded.

Results

In our study group the rates of hospitalization, emergency room visits and systemic steroid use in the year before pregnancy were 13%, 46.9% and 18.8%, respectively. The rate of regular asthma medication use was only 32% at that period and increased to 44% during pregnancy. However, hospitalization, emergency room visits, systemic steroid usage rates remained unchanged and according to patients’ own evaluations, 44% of asthmatics pointed out that their asthma had worsened during pregnancy. No statistically significant difference was detected in terms of pregnancy/labour complication between asthmatic and non-asthmatics.

Conclusions

Contrary to some previous studies, in our study regular use of asthma drugs increased during pregnancy. The uncontrolled condition of their asthma before and during pregnancy and the idea that their asthma worsened during pregnancy might force the patients to use medication more regularly.