WEDNESDAY, Sept. 27, 2017 (HealthDay News) -- Infants born early in a full-term pregnancy have a higher risk of poor heart-lung fitness later in life, a new study suggests.
The study included nearly 800 people in Northern Ireland who were born at full-term (37 to 42 weeks) and had their cardiorespiratory fitness assessed at ages 12, 15 and 22.
Those born at 37 to 38 weeks had a 57 percent higher risk of poor heart-lung fitness when they were teens and young adults compared to those born between 39 and 42 weeks.
Each extra week of full-term pregnancy was associated with a 14 percent reduced risk, the Australian researchers reported.
Diet, physical activity and smoking behavior did not affect the findings, according to the study published Sept. 27 in the Journal of the American Heart Association.
"We believe that earlier births -- even within the at-term range -- may interrupt normal development and lead to permanent changes of tissues and organs, thereby affecting cardiorespiratory fitness," study lead author Isabel Ferreira said in a journal news release.
"As such, recent trends towards deliveries at shorter gestational lengths within the at-term period are worrisome," added Ferreira, an associate professor at the University of Queensland.
Cardiorespiratory fitness refers to the ability to supply oxygen to muscles during physical activity. It also affects metabolic and heart health throughout a person's life. Previous research has found that people who were born prematurely have lower cardiorespiratory fitness levels.
"Health care providers and mothers should be informed of the lifelong health risks that early term deliveries may have on their offspring and refrain from these [e.g., scheduled caesarean sections or induced labor] unless there is a medical indication to anticipate deliveries," Ferreira suggested.
The U.S. National Heart, Lung, and Blood Institute offers a guide to a healthy heart.