Asthma is a disease characterized by difficulty breathing, and an asthma attack can bring on bouts of coughing and wheezing in those afflicted with this condition. About six million children in the United States have asthma. The CDC estimates that 1 in 6 children with asthma require emergency treatment each year, and 1 in 20 children with asthma require hospitalization.
Many genetic and environmental factors can increase a child’s risk of developing asthma. Early life exposures like the mother's diet and cesarean delivery can even increase the risk of asthma. Last year, a meta-analysis suggested infertility treatments as an additional early life exposure impacting asthma risk. However, studies on the association between infertility treatment and asthma risk are limited, especially in cohorts of children in the United States.
Given the suggestive yet limited information available, a group of researchers from various institutions initiated a large-scale study to investigate whether children conceived with infertility treatment exhibited an elevated risk of developing asthma. The results of this study were recently published in the journal Human Reproduction.
The data emerged from the Upstate KIDS Study, a collaborative prospective cohort study that “tracked the growth, motor, and social development of children to examine associations with parental medical conditions and characteristics, including infertility treatments, environmental, and other exposures.” The study enrolled over 5,000 mothers and their 6,171 children born between 2008 and 2010.
Mothers enrolled in the study reported the fertility agents used to become pregnant. The analysis found that 22% of the mothers used Assisted Reproductive Technology (ART), 20% used ovulation induction (OI) and/or intrauterine insemination (IUI), and 58% used no infertility treatment. While the researchers found no significant differences in asthma risk between children conceived with ART versus OI/IUI, they detected substantial impacts of infertility treatment overall. The analysis revealed that children conceived with any infertility treatment exhibited an increased risk of persistent wheeze by age three when compared to those conceived without treatment. By age nine, children conceived with treatment were more likely to have asthma than those conceived without treatment.
Overall, the authors conclude that both ART and OI/IUI increase the risk of children developing asthma at a young age. This data may encourage additional studies investigating the mechanisms underlying the link between these infertility treatments and asthma. A clear picture of the mechanistic links may assist with diagnosis and therapeutic development for treating asthma.