PETA is no stranger to absurd ads (including borderline pornographic ones) that use questionably accurate scientific evidence to promote veganism. Its newest one is no different: It claims women who eat chicken while pregnant give birth to sons with smaller penises because of chemicals called phthalates, which have been found in small quantities in chicken.
Aside from the fact that it's ridiculous to worry about the size of your child's penis, the phthalate study PETA cites doesn't actually make a connection between eating chicken and penis size—it never even mentions chicken! The study does look at phthalate exposure among pregnant women, but the link between exposure and their son's penis size is limited.
The debate about phthalates and their antiandrogen (a.k.a. testosterone-blocking) effect isn't new, but the connection has never been made in research on humans, says Sherry Ross, M.D., an OB/GYN at Providence Saint John’s Health Center in Santa Monica, CA. "Phthalates are everywhere, from the water we drink to the makeup we wear to the food we eat," she says. "Until better and more reliable studies can be done on the dangers of phthalates, I wouldn’t worry about eating chicken during pregnancy."
As an obstetrician, Ross advises pregnant women to avoid certain foods (undercooked meats, raw fish, and unpasteurized juice and cheese), but chicken is not one of them. "Isolating chicken consumption during pregnancy has merit in the eyes of PETA but not the medical community," Ross says.