Sexually active women who are not using birth control should refrain from alcohol to avoid the risk of giving birth to babies with fetal alcohol spectrum disorders, even if those women are not yet known to be pregnant, the Centers for Disease Control and Prevention has recommended.

The C.D.C. report, released on Tuesday, estimated that 3.3 million women between the ages of 15 and 44 who drink alcohol risk exposing their infants to the disorders, which can stunt children’s growth and cause lifelong disabilities. The report, which appeared to refer exclusively to heterosexual sex, also said that three in four women who intend to get pregnant do not stop drinking alcohol when they stop using birth control.

“The risk is real. Why take the chance?” Anne Schuchat, principal deputy director of the C.D.C., said in a statement.

Alcohol consumption during pregnancy has been widely linked to stunted physical, mental and behavioral development of children. In October, a report by the American Academy of Pediatrics declared that “no amount of alcohol should be considered safe to drink during any trimester of pregnancy.”