Pregnant women with higher levels of certain hormone-disrupting chemicals in their bodies had elevated blood pressure across pregnancy, according to a new study in the Journal of the Endocrine Society.
The chemicals, called phthalates, are widely used to soften plastics and to hold fragrance in shampoos, lotions, perfumes and cleaning products.
Researchers at the Harvard T.H. Chan School of Public Health measured phthalate metabolites in the urine of 338 pregnant participants at three points during pregnancy. The women were drawn from the Environmental Reproductive and Glucose Outcomes (ERGO) Study.
Women with higher urine concentrations of fragrance-associated phthalates and phthalates from personal care products showed higher systolic and diastolic blood pressure later in pregnancy, the authors reported. About 13 percent of the participants developed a hypertensive disorder of pregnancy.
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"Our study suggests that having higher concentrations of personal care products-associated chemicals, known as phthalates, in the body might contribute to elevated blood pressure in pregnancy," said Kimberly Parra, Ph.D., of Harvard T.H. Chan School of Public Health, in a statement from the Endocrine Society.
The finding fits a broader pattern. A 2024 ECHO analysis of more than 3,400 US pregnant participants tied a quartile increase in a combined phthalate mixture to a 27 percent higher risk of preeclampsia or eclampsia.
Hypertensive disorders remain a leading cause of maternal complications and can escalate into preeclampsia, a condition that can damage organs and require early delivery.
Where the exposure comes from
Phthalates rarely appear on cosmetic labels because US law treats fragrance blends as trade secrets. The FDA lists diethyl phthalate, or DEP, as the phthalate still commonly used in cosmetics, mainly as a fixative in fragrance.
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Historically, dibutyl phthalate turned up in nail polish and dimethyl phthalate in hair spray. The FDA says DEP as currently used in cosmetics and fragrances does not raise safety concerns in its view.
Independent researchers continue to publish findings linking phthalate exposure to hormonal and cardiovascular outcomes.
Exposure is not limited to the bathroom shelf. Phthalates leach into food from soft plastic packaging, cling wrap and takeout containers, particularly with heat or fatty foods. They also turn up in household dust from vinyl flooring and shower curtains.
Practical steps during pregnancy
The study shows association, not proof of cause. Because everyday exposure is so widespread, Parra suggested limiting personal care products that carry added fragrance and choosing phthalate-free alternatives when the label allows.
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Simple swaps also help. Store food in glass or stainless steel rather than soft plastic, especially anything hot or oily. Avoid microwaving food in plastic containers or with plastic wrap touching the food.
Look for unscented shampoo, lotion and detergent where possible.
Women who notice swelling, severe headaches, vision changes or a sudden rise in blood pressure during pregnancy should contact their obstetric provider promptly. These can be signs of preeclampsia and require medical assessment.
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