Do You Want to Have a Girl?

Exposure to some chemicals may favor conception of females


Women exposed to higher levels of polychlorinated biphenyls, or PCBs, were 33 percent less likely to give birth to boys, according to a recent study. Researchers speculate that the chemicals, once widely used in manufacturing but now banned, either favor conception of females or result in greater losses of male fetuses. Women who are or hope to become pregnant should not eat fish from lakes contaminated by PCBs, and they should avoid products containing polybrominated diphenyl ethers (PBDEs), which are similar chemically and found in flame retardants and some foam products.