Hormone disruptor phthalate chemicals were associated with nearly 56,600 preterm births in the United States in 2018, according to a study published online Feb. 6 in The Lancet Planetary Health.
Leonardo Trasande, M.D., from the New York University Grossman School of Medicine in New York City, and colleagues examined associations between 20 phthalate metabolites and birth weight and gestational age. The analysis included data from 5,006 mother-child dyads participating in the U.S. National Institutes of Health Environmental Influences on Child Health Outcomes Program (1998 to 2022).
The rate of preterm birth among Black American women is significantly higher than that of white women, averaging at 14.6% of births.
The researchers found that phthalic acid, diisodecyl phthalate (DiDP), di-n-octyl phthalate (DnOP), and diisononyl phthalate (DiNP) were most strongly associated with gestational age, birth length, and birth weight compared with di-2-ethylhexyl phthalate (DEHP) or other metabolite groupings. While DEHP was associated with preterm birth (odds ratio [OR], 1.45), the risks per log10 increase were higher for phthalic acid (OR, 2.71), DiNP (OR, 2.25), DiDP (OR, 1.69), and DnOP (OR, 2.90). An estimated 56,595 phthalate-attributable preterm birth cases occurred in 2018 with associated costs of US$3.84 billion.
“We identified associations of phthalate exposure with decreased gestational age in a large and diverse sample generally representative of the USA,” the authors write. “This finding suggests the adverse consequences of substitution of DEHP with chemically similar phthalates and need to regulate chemicals with similar properties as a class.”