The chemicals, called phthalates, are used to soften plastic and can be found in thousands of consumer items including plastic containers and wrapping, beauty care products and toys.
Phthalates have been known for decades to be "hormone disruptors" which affect a person's endocrine system and have been previously linked to obesity, heart disease, some cancers and fertility problems.
Because they affect hormones, these chemicals "can precipitate early labor and early birth", lead study author Leonardo Trasande of New York University's Langone Health center says.