Feb. 7, 2024 – Chemicals used to make everyday plastic items like food containers and cosmetic packages may be linked to the rise in preterm births, according to a new study.
Preterm births are those that occur before the 37th week of pregnancy, and the CDC warned earlier this month that they are on the rise.
For the study, the researchers looked for chemicals called phthalates in about 5,000 U.S. mothers by analyzing their urine at various points during their pregnancies. Phthalates have long been known to affect hormone functions that can sometimes affect other body processes.
The findings were published in this month’s edition of The Lancet Planetary Health. The researchers concluded that exposure to several specific phthalates may significantly increase the risk of preterm birth and may be linked to as many as 56,595 preterm births annually.
The report authors specifically called for manufacturers to seek an alternative chemical for a phthalate known as DHEP, which helps make plastic flexible and is used in an array of products, including furniture upholstery, garden hoses, baby pants, toys, and medical tubing.
"Our findings uncover the tremendous medical and financial burden of preterm births we believe are connected to phthalates, adding to the vast body of evidence that these chemicals present a serious danger to human health. There is a clear opportunity here to lessen these risks by either using safer plastic materials or by reducing the use of plastic altogether whenever possible," said study lead author Leonardo Trasande, MD, in a statement. (Trasande is a pediatrician at NYU Langone Health, professor at the NYU Grossman School of Medicine, and a renowned expert in the field of children’s environmental health.)
Among annual U.S. live births, about 8% of babies have low birth weight, and about 10% are preterm, the authors noted. Low birth weight and low gestational age (the time between conception and birth) are known predictors of health problems both in early life and throughout a person’s lifespan. Babies with low birth weight or short gestational age are at increased risk of poor academic performance later in life, as well as heart disease and diabetes, according to NYU Langone Health.
The researchers sought to better understand potential links between phthalates and birth outcomes because the chemicals are known to “induce inflammation and oxidative stress, and are endocrine disruptors,” they wrote, adding that all three effects are known to interact in ways that can affect the placenta and pregnancy complications.
Overall, they found that evidence of phthalates in the pregnant women’s urine was similar in terms of concentration levels compared to those previously found in other studies of women of childbearing age. Evidence of high concentrations of specific phthalates varied among pregnant women based on their race or ethnicity, but no differences were identified based on the sex of the baby.
The researchers said their findings are of “great concern,” particularly because some of the phthalates their study linked to preterm birth are currently being used by manufacturers of food packaging as alternatives to the already concerning DHEP phthalate.
“The adverse consequences of chemically similar phthalates to DEHP suggest a need to regulate chemicals with similar properties as a class,” the authors concluded.
