Evaluation of contaminated drinking water and preterm birth, small for gestational age, and birth weight at Marine Corps Base Camp Lejeune, North Carolina: A cross-sectional study
The purpose of this study was to determine if maternal exposures to contaminants in drinking water at Camp Lejeune were associated with preterm birth and fetal growth retardation. This study is a reanalysis of a previous study, which incorrectly categorized as “unexposed” some maternal exposures before June 1972 based on information available at the time.Besides considering the re-categorized births to exposed women, the Agency for Toxic Substances and Disease Registry (ATSDR) recreated monthly estimates of past levels of drinking water contamination using computer models. These estimates were not available when the first study was conducted.
Drinking water at Camp Lejeune was contaminated with volatile organic compounds (VOCs) including trichloroethylene (TCE), tetrachloroethylene (PCE), benzene, 1,2-dichloroethylene (DCE) and vinyl chloride from the 1950s through 1985.
The study included live singleton births 28-47 weeks gestation weighing 500 grams or more. The births occurred between 1968 and 1985 to women who resided on base for at least one week before giving birth. These years were chosen because computerized birth certificates in North Carolina became available in 1968 and the contaminated wells on base were shut down in 1985. The authors cross referenced birth certificate data for Onslow County, NC, where Camp Lejeune is located, with Camp Lejeune housing records and identified 11,896 births that met the study criteria.
Outcomes of interest in this study were preterm birth and fetal growth retardation. Fetal growth retardation was measured by reduced mean birth weight (MBW), term low birth weight (TLBW), and small for gestational age (SGA). Information about these outcomes was obtained from birth certificates. Preterm births were defined as births occurring at less than 37 weeks of gestation. Gestational age was calculated using date of mother’s last menstrual period from the birth certificate. TLBW was defined as full-term babies (37 weeks or more gestation) weighing less than 2,500 grams at birth. SGA births were defined as births weighing less than the 10th percentiles using sex- and race-specific weight by gestational week norms. For the MBW analysis, only full-term infants were included.