Exposure during early pregnancy to some phthalates – man–made chemicals commonly found in household plastics, food and personal care products – can have adverse impacts on developing fetuses, according to a new study led by Dr. Sheela Sathyanarayana, a pediatric environmental health specialist at Seattle Children’s Research Institute and associate professor at the University of Washington.

The study, published in The Journal of Clinical Endocrinology & Metabolism, found that increases in exposure to certain phthalates during the first trimester of pregnancy was associated with higher estrogen concentrations and lower testosterone concentrations in the fetus, thus increasing the chance of a genital abnormality in male babies at birth.

The study reinforces that some phthalates are endocrine disrupting chemicals (EDCs) and can alter concentrations of naturally–produced hormones, which help regulate and control different cells and organs in the body. Sathyanarayana’s previous research has directly linked fetal exposure to diethylhexyl phthalate (DEHP) to the development of genital abnormalities and increased risk of future reproductive health issues in boys.

The researchers found that increases in phthalate exposure in early pregnancy was associated with higher estrogen concentrations (MBzP, DEHP, MiBP) and lower testosterone (MCNP and DEHP) concentrations. They also found that having higher testosterone in pregnancy was associated with a lower chance of having a male baby with a genital abnormality, which means that anything that reduces testosterone, like the hormone DEHP, will increase chances of having a male baby with a genital abnormality.

Phthalates are used to soften and increase the flexibility of plastic and vinyl products; including medical tubing, food storage containers, flooring, wallpaper, shampoo, lotion makeup and perfume. Food is the most likely source of exposure to the most harmful phthalates. To limit exposure, expecting moms should do the following:

• Buy low–fat dairy products like skim milk and low fat cheeses instead of high–fat dairy products like cream and whole milk.
• Buy fresh or frozen fruits whenever possible. Avoid canned and processed foods.
• Look for items that are labeled phthalate or BPA–free.
• Minimize personal care products, and focus on simple products with clear ingredients.
• Use glass, stainless steel, ceramic or wood to hold and store foods instead of plastics, and do not microwave food in plastic.
• Do not heat a baby’s milk or food in plastics or put hot liquids in plastic products like sippy cups.
• Check plastic symbols and avoid plastics known to contain phthalates including numbers 3 (PVC and vinyl), 6 (polystyrene foam) and 7 (other, can contain BPA).
• Perform frequent handwashing.
• Minimize handling of receipts.
• Take shoes off at home to avoid tracking dust in that may contain phthalates.
• Keep carpets and windowsills clean because these are areas that can often collect phthalates.