A new study of expectant mothers suggests that a group of common environmental contaminants called phthalates, which are present in many industrial and consumer products including everyday personal care items, may contribute to the country's alarming rise in premature births.
Researchers at the University of Michigan School of Public Health found that women who deliver prematurely have, on average, up to three times the phthalate level in their urine compared to women who carry to term.
Professors John Meeker, Rita Loch-Caruso and Howard Hu of the SPH Department of Environmental Health Sciences and collaborators from the National Institute of Public Health in Mexico and the U.S. Centers for Disease Control and Prevention analyzed data from a larger study directed by Hu, which follows a cohort of Mexican women recruited during pre-natal visits at one of four clinics of the Mexican Institute of Social Security in Mexico City.
Meeker and colleagues looked at data from 60 women: 30 who carried to term and 30 who delivered prematurely (defined as less than 37 weeks gestation). They analyzed urine samples collected during the third trimester and compared them to the control group who carried to term. They found significantly higher phthalate metabolite levels in the women who delivered prematurely.
Premature birth is a significant risk factor for many health problems in childhood that can persist into adulthood, Meeker says. In the United States, premature births have increased by more than 30 percent since 1981 and by 18 percent since 1990. In 2004, premature births accounted for 12.8 percent of live births nationwide.
Premature births, he says, account for one-third of infant deaths in the United States, making it the leading cause of neonatal mortality. Being born too early can also lead to chronic health problems such as blindness, deafness, cerebral palsy, low IQ and more.