Heavier newborn babies have higher risk of developing atrial fibrillation as adults

BEIJING, China — Health experts say a big birth weight usually means that child will be a big adult. An international study finds a larger birth weight can also spell trouble for that child’s heart later in life. Researchers say babies weighing well over eight pounds or more have a significantly higher risk for developing atrial fibrillation as an adult.

Atrial fibrillation is the most common heart rhythm disorder. It affects over 40 million people worldwide and can cause a rapid heart rate which may lead to poor blood flow. Patients with AFib have upper heart chambers which beat out of sync with their lower chambers. The study finds people with AFib also are at five times greater risk of suffering a stroke.

“Our results suggest that the risk of atrial fibrillation in adulthood may be higher for large newborns (over 4,000 grams or 8 pounds 13 ounces) than those with normal birth weight. Preventing elevated birth weight could be a novel way to avoid atrial fibrillation in offspring – for example with a balanced diet and regular check-ups during pregnancy, particularly for women who are overweight, obese or have diabetes,” study author Dr. Songzan Chen of Zhejiang University says in a media release.

“People born with a high weight should adopt a healthy lifestyle to lower their likelihood of developing the heart rhythm disorder.”

Atrial fibrillation warning signs in the genes

The study examined data on 321,223 individuals from a genome-wide association study (GWAS). This helped researchers identify 132 genetic variants tied to birth weight. Next, the team learned which of these genes also play a role in the development of atrial fibrillation. To find the link, the study used data from another 537,409 participants in the Atrial Fibrillation Consortium. Only 55,114 of these individuals actually have the condition.

The results reveal babies weighing at least one pound (482 grams) more than the average birth weight of 7.48 pounds have a 30-percent higher chance of developing the heart rhythm disorder.

“A major strength of our study is the methodology, which allows us to conclude that there may be a causal relationship between high birth weight and atrial fibrillation. However, we cannot discount the possibility that adult height and weight may be the reasons for the connection,” Dr. Chen explains. “Birth weight is a robust predictor for adult height, and taller people are more likely to develop atrial fibrillation. Previous research has shown that the link between birth weight and atrial fibrillation was weaker when adult weight was taken into account.”

“This study provides genetic evidence for the association between elevated birth weight and the increased risk of atrial fibrillation. From this research, we can see that reducing the number of newborns with elevated birth weight is probably considered as a feasible prevention to ease the burden of atrial fibrillation,” Professor Guosheng Fu of Sir Run Run Shaw Hospital adds. “Therefore, pregnant women should pay more attention to the diet control and regular check-ups, especially for those with obesity or diabetes. Equally important, people born with a high birth weight should be aware of reducing other risk factors to prevent atrial fibrillation.”

The study appears in the European Heart Journal.