Pregnant women exposed to phthalates, a group of chemicals used in many products, may be at increased risk for preterm birth, studies have found. Now a new study has found that exposure even before conception may increase the risk.
Phthalates are found in plastic toys, hair sprays, soaps, perfumes and other products and can contaminate foods by contact with packaging. The new study, in JAMA Network Open, included 419 women and 229 men seeking treatment at a fertility treatment center in Boston.
The researchers measured urine concentrations of phthalate metabolites in men and women at the start of the study, and then again in women just before ovulation and in men at the start of fertility treatment. From 2005 through 2018, there were 423 singleton births, 34 at less than 37 weeks’ gestation.
After controlling for other known risk factors, including phthalate exposure during pregnancy, the scientists found that high levels of exposure to two of the phthalates tested was associated with a 50 percent to 70 percent increased relative risk of preterm birth. None of the other nine chemicals tested nor the fathers’ levels of phthalates were associated with an increased risk of prematurity.
“This study suggests that even before you try to get pregnant you can actually affect the child’s health,” said the senior author, Carmen Messerlian, an assistant professor of epidemiology at Harvard. “People planning a pregnancy should reduce exposure before conceiving.”
