Pregnant women who have a certain genetic makeup that affects how their body cleans out chemicals might have babies with higher birth weights if they’re exposed to more parabens — common preservatives in cosmetics — during pregnancy.

Pregnant women who can't clear certain chemicals well due to their genes might have bigger babies if they're exposed to more methyl paraben, a common ingredient in personal care products.

Pregnant women who have a certain gene variation might have babies with higher birth weights if they’re exposed to more propyl paraben, a chemical found in some personal care products.

Pregnant women who have a certain gene change might go into labor a little later if they have more of a chemical called propyl paraben in their bodies, based on what’s found in their urine.

Being missing a certain gene (GSTT1) doesn’t change how a mom’s exposure to parabens during pregnancy affects her baby’s birth weight, length, or how long she carries the baby.