Pregnant expatriates may wish to consider relocating abroad to somewhere with clean air, following research that linked prenatal exposure to airborne pollutants with obesity in childhood.
The study, which was undertaken by Columbia University's Mailman School of Public Health and published in the American Journal of Epidemiology, involved the analysis of expectant mothers in New York City.
It found the females who breathed in higher concentrations of polycyclic aromatic hydrocarbons (PAH) more than doubled the likelihood of their children being obese by the age of seven when compared with those who had lower levels of exposure.
Being overweight at an early age could substantially increase the chance of a person having to make a claim on an expatriate health insurance policy, with the US' Centers for Disease Control and Prevention (CDC) noting heavy youths have a greater risk of suffering from high blood pressure or unhealthy cholesterol levels.
These factors are related to cardiovascular disease, the group noted.
Furthermore, obese youngsters are more likely to be affected by bone and joint problems, psychological and social issues and sleep apnoea, while heaviness has also been linked to prediabetes, which can lead to diabetes.
Overweight children and teenagers also face long-term health problems, including heart disease, cancer and osteoarthritis, as they have an elevated likelihood of being obese in adulthood, the CDC remarked.
Researchers led by Andrew Rundle, a professor of epidemiology at Columbia's Mailman School of Public Health, recruited 702 pregnant women who did not smoke.
All participants lived in low-income areas in south Bronx or northern Manhattan and identified themselves as either Dominican or African-American.
The scientists discovered those who were exposed to high levels of PAH had children who were 1.79 times more likely to be obese when they reached five years old, with this figure reaching 2.26 by the age of seven.
Previous investigations have shown PAH can potentially cause a spike in fat mass and prevent lipolysis – a process wherein cells carrying fatty compounds become smaller.
"For many people who don't have the resources to buy healthy food or don't have the time to exercise, prenatal exposure to air pollution may tip the scales, making them even more susceptible to obesity," Mr Rundle stated.