Researchers from the University of Pittsburgh Graduate School of Public Health examining the proximity of pregnant women to unconventional gas drilling sites have found that those living closest to gas wells drilled with hydraulic fracturing may be more likely to have babies with lower birth weights than those living farther away.

This finding was obtained following an analysis of southwestern Pennsylvania birth records. The results of the study, published in PLOS ONE and funded by the Heinz Endowments, suggest that further research should be conducted on this association.

After analysis, the researchers found that the group of mothers who lived closest to a high density of fracking wells were 34% more likely to give birth to infants who were small for gestational age — babies with birth weights below the smallest 10% when compared with their peers — than the group of mothers who lived farthest away.