Babies born prematurely before 37 weeks have an increased risk of asthma, says a new review study published in the journal PLoS Medicine.
The World Health Organization (WHO) estimates that 15 million babies are born prematurely each year, making the health risks associated with premature birth a serious issue. Prematurity increases the risk of infection, respiratory issues, developmental problems, and even death.
Asthma is a chronic disorder that causes the airways of the lungs to swell and narrow, leading to wheezing, shortness of breath, chest tightness, and coughing. Untreated asthma can lead to death.
For the present study, the researchers analyzed data from 30 studies on more than 1.5 million children born since the 1990s from six continents. The majority of the studies took place in Europe.
Drawing on previous research on preterm children born between the 1960s and 1980s in which many of the children developed asthma, the researchers in the present study note that premature babies often experience breathing problems because of lung immaturity.
The researchers also wanted to know whether improved care for premature babies since the 1980s had affected the risk of developing asthma.
The study revealed that, while eight percent of full term babies develop asthma, the chronic disorder affects 14 percent of premature babies. In other words, a child born before 37 weeks is almost 50 percent more likely to develop asthma.
Furthermore, children born two months prematurely are three times more likely to develop asthma than babies born after 37 weeks.
The increased risk of asthma remains the same for preschoolers and school-age children, indicating that premature children do no outgrow the increased risk. The researchers note in the review study, “The current findings do not support prior suggestions that the association between preterm birth and wheezing disorders becomes less prominent with increasing age. Instead, the strength of the association was similar across age groups [up to 18 years].”
Lead study author Dr. Jasper Been of the Centre for Population Health Sciences at the University of Edinburgh in Scotland comments on the findings:
“Doctors and parents need to be aware of the increased risks of asthma in premature babies, in order to make early diagnosis and intervention possible. By changing the way we monitor and treat children born preterm, we hope to decrease the future risks of serious breathing problems, including asthma. Our findings should help find better ways to prevent and treat asthma and asthma-like symptoms in those born preterm.”
Additional research is needed to understand underlying mechanisms that cause the increased risk of asthma in children born prematurely.
In the meanwhile, pregnant women can take a few steps to reduce the risk and avoid a premature birth.
Dr. Samantha Walker, executive director of research and policy at Asthma UK, emphasizes the importance of current asthma medications: “Standard asthma medicine is very safe to use in pregnancy, and by far the most important way to reduce this risk is for pregnant women to take their medication as prescribed.”
Pregnant women are also advised to maintain a healthy weight, stay active, avoid stress, and not smoke. Smoking, in particular, is linked to both an increased risk of premature birth and an increased risk of respiratory problems like asthma in offspring.
Says Dr. Been to Medical News Today: “An important factor that causes both preterm birth and asthma, particularly in those born preterm, is tobacco smoke exposure before birth. Our current research focuses on evaluating interventions to address this issue.”
Another recent study also linked maternal infections to an increased risk of prematurity.
Premature Babies ‘at Higher Risk for Asthma’: http://www.medicalnewstoday.com/articles/271775.php
Preterm Birth and Childhood Wheezing Disorders: A Systematic Review and Meta-Analysis: http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pmed.1001596
Premature Birth Linked to Asthma in Childhood: http://www.webmd.com/asthma/news/20140128/premature-birth-linked-to-asthma-wheezing-in-childhood
Premature Newborn Baby: http://www.freeimages.com/photo/755159