Pregnancy-Onset Asthma Increases Risk of Spontaneous Preterm Births

According to a recent study published in The Journal of Allergy and Clinical Immunology: In Practice, pregnancy-onset asthma is associated with an increased risk of spontaneous preterm births compared with asthma diagnosed prior to pregnancy.

The investigators acknowledged that “asthma adversely affects both the mother and the fetus” and aimed to explore whether pregnancy-onset asthma leads to worse perinatal outcomes compared with prepregnancy asthma.

A total of 335 women were included in the retrospective cohort analysis. Patients were divided into groups based on whether the asthma was diagnosed during (n=39) or before (n=296) pregnancy. Clinical characteristics, perinatal outcomes, and asthma exacerbations (AEs) were compared between groups.

Notably, the results of the study showed that all women in the pregnancy-onset asthma group experienced AEs during pregnancy.

Additionally, the pregnancy-onset asthma group had a higher proportion of chronic hypertension, chronic hypertension with superimposed preeclampsia, and spontaneous preterm births compared with the prepregnancy asthma group.

After adjusting for age, body mass index, onset of asthma during pregnancy, and severity of AEs, multivariate analysis showed that pregnancy-onset asthma was an independent risk factor for spontaneous preterm birth, with an adjusted odds ratio (aOR) of 7.71 (95% CI, 1.30-46.12). Furthermore, severe AE was found to be an independent risk factor for gestational hypertension and preeclampsia (aOR, 3.58; 95% CI, 1.30-9.87).

“Obstetricians should be vigilant for signs of asthma onset during pregnancy,” the investigators cautioned. They further recommended that other health care providers remain cognizant of the symptoms of gestational hypertension and preeclampsia in pregnant women with pre-existing or new-onset asthma.