Various Perinatal Risks Associated With Maternal Asthma Diagnosis

Preterm birth, perinatal mortality, low birth weight, fetal growth restriction, and asphyxia may be associated with the maternal diagnosis of asthma, according to a study published in PLoS One.

Researchers collected data from a national population register-based cohort investigation of singleton live and still births in Finland to assess whether there was an association between perinatal risk and a maternal diagnosis of asthma. In addition, they assessed the effects and complication risks associated with the use of asthma medication in pregnant women diagnosed with asthma. 

A total of 3 groups of women were identified in this study: women who were not diagnosed with asthma and did not use asthma medications (controls; n=898,333), women with confirmed asthma not using asthma medication (untreated asthma; n=7624), and women diagnosed with asthma using asthma medications (treated; n=19,050). Women without the diagnosis of asthma who were using asthma medications were not included in this study (n=37,398).

Infants born to mothers diagnosed with asthma, compared with those born to mothers in the control group, had an increased risk for perinatal mortality (adjusted odds ratio [aOR], 1.26; 95% CI, 1.07-1.48; P =.0067), preterm birth (aOR, 1.18; 95% CI 1.12-1.25; P <.0001), low birth weight (aOR, 1.29; 95% CI; 1.21-1.37; P <.0001), fetal growth restriction (aOR, 1.32; 95% CI, 1.24-1.40; P <.0001), Apgar score <7 at 1 minute and 5 minutes (aOR, 1.26; 95% CI, 1.19-1.32; P <.0001 and aOR, 1.21; 95% CI 1.09-1.35; P =.0005, respectively), delivery by urgent Cesarean section (aOR, 1.23; 95% CI, 1.18-1.28; P <.0001), birth asphyxia (aOR, 1.07; 95% CI, 1.00-1.14; P =.0454), and umbilical arterial pH<7.1 (aOR, 1.17; 95% CI, 1.08-1.26; P <.00001). 

However, in a subgroup analysis, mothers diagnosed with and treated for asthma had a lower risk of having a preterm birth infant compared with mothers with untreated asthma but had a higher risk for fetal growth restrictions and asphyxia.

When the number of asthma treatment medications was assessed, there were no logistic increases in perinatal mortality or preterm birth; however, each purchased asthma medication group increased the maternal risk of having an infant with low birth weight by 6% (aOR, 1.06; 95% CI, 1.00-1.13; P =.0356) and fetal growth restriction by 13% (aOR, 1.13; 95% CI, 1.07-1.19; P <.0001).

The researchers suggested the observed increase in perinatal mortality associated with a maternal diagnosis of asthma is related to the disease process itself. Interestingly, there was a decrease in the risk for preterm birth in women using asthma medication, but no decrease in the risk for fetal growth restriction or perinatal death. The authors concluded that the risks for perinatal mortality, preterm birth, low birth weight, fetal growth restriction, and asphyxia were increased in women diagnosed with asthma, with only a reduction in the risk for preterm delivery with the use of asthma medications. 

Clinicians should carefully consider the perinatal risk in women diagnosed with asthma and the benefits vs risks associated with the maternal use of asthma medications.

Reference

Kemppainen M, Lahesmaa-Korpinen AM, Kuppi P, et al. Maternal asthma is associated with increased risk of perinatal mortality [published online May 18, 2018]. PLoS One. doi:10.1371/journal.pone.0197593