Babies who are born too early at an abnormally low birth weight can face a lifetime of acute and chronic health problems. So it's not surprising that identifying the causes and reducing the occurrence of preterm and low birth weight deliveries have been the subject of much research.

A recent study found a novel factor contributing to better birth weights in newborns.

Increased access to green spaces during pregnancy seems to help improve the likelihood that a baby will be born full-term and at a healthy weight. Researchers defined green spaces as land that is partly or completely covered with grass, trees, shrubs or other vegetation. These green zones can be city parks, community gardens — even cemeteries.

As the amount of surrounding greenness increased during pregnancy, the incidence of low birth weight infants decreased.

Spending time outdoors in green spaces has been associated with other positive health outcomes including improved mental and physical health, and a longer life. These observations may be the result of a few different mechanisms including increased opportunity for physical exercise, improved opportunities for socializing, and spending time in less noise and air pollution.

The Spanish and Israeli researchers were interested to see if pregnant women who lived near green spaces had healthier babies. They looked at 39,132 live births that took place between 2000 and 2006 and compared each newborn's birth weight and gestational age at delivery to the amount of green space and the depth of greenness around the mother’s neighborhood.

The babies whose mothers lived near parks or other green areas were more likely to be born at healthy birth weights. The results clearly demonstrated that as the amount of surrounding greenness increased during pregnancy, the incidence of low birth weight infants decreased.

Unfortunately, living close to green space did not positively influence the likelihood of preterm delivery. That rate remained the same regardless of how green a mother-to-be's neighborhood was.

The reasons for the positive effect on birth weight are not clear, but some earlier Israeli studies have shown that green spaces decrease the environmental temperature in desert communities and lowers air and noise pollution levels. These changes could contribute to the observed positive outcomes by decreasing physiologic and psychosocial stressors on pregnant women.

The researchers conclude that green space availability is a concept worth further exploration by those who are interested in improving pregnancy outcomes. Pregnant women might take a hint from the scientific literature and consider exploring the availability of green spaces in their neighborhood.

The study is published in Occupational and Environmental Medicine.