Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2016 Mar;27(2):163-72.
doi: 10.1097/EDE.0000000000000387.

Unconventional Natural Gas Development and Birth Outcomes in Pennsylvania, USA

Free PMC article

Unconventional Natural Gas Development and Birth Outcomes in Pennsylvania, USA

Joan A Casey et al. Epidemiology. .
Free PMC article


Background: Unconventional natural gas development has expanded rapidly. In Pennsylvania, the number of producing wells increased from 0 in 2005 to 3,689 in 2013. Few publications have focused on unconventional natural gas development and birth outcomes.

Methods: We performed a retrospective cohort study using electronic health record data on 9,384 mothers linked to 10,946 neonates in the Geisinger Health System from January 2009 to January 2013. We estimated cumulative exposure to unconventional natural gas development activity with an inverse-distance squared model that incorporated distance to the mother's home; dates and durations of well pad development, drilling, and hydraulic fracturing; and production volume during the pregnancy. We used multilevel linear and logistic regression models to examine associations between activity index quartile and term birth weight, preterm birth, low 5-minute Apgar score and small size for gestational age birth, while controlling for potential confounding variables.

Results: In adjusted models, there was an association between unconventional natural gas development activity and preterm birth that increased across quartiles, with a fourth quartile odds ratio of 1.4 (95% confidence interval = 1.0, 1.9). There were no associations of activity with Apgar score, small for gestational age birth, or term birth weight (after adjustment for year). In a posthoc analysis, there was an association with physician-recorded high-risk pregnancy identified from the problem list (fourth vs. first quartile, 1.3 [95% confidence interval = 1.1, 1.7]).

Conclusion: Prenatal residential exposure to unconventional natural gas development activity was associated with two pregnancy outcomes, adding to evidence that unconventional natural gas development may impact health.See Video Abstract at


Figure 1
Figure 1
Flow diagram of study population assembly
Figure 2
Figure 2
The Marcellus shale extent, the location of spudded and producing wells as of December 2012, the location of the two Geisinger Health System hospitals and the primary and surrounding Geisinger counties. Annotation indicates the number of neonates born to mothers residing in each county. GMC = Geisinger Medical Center. GWV = Geisinger Wyoming Valley.

Comment in

Similar articles

See all similar articles

Cited by 44 articles

See all "Cited by" articles

Publication types

MeSH terms