A young woman who usually sips a glass of wine turns down an offer of alcohol at a party. Maybe she’s pregnant? So widely is it presumed that women don’t drink when expecting that sudden-onset teetotaling is often a clue to a woman’s fecundity.

For good reason — 90 percent of women who are pregnant do follow federal guidelines and don’t drink at all, according to

Of course, that means that 10 percent of pregnant women ages 18 to 44 do report having at least one drink during the past 30 days.

In addition, 3 percent of pregnant women admit to binge drinking, which is defined as consuming four or more alcoholic beverages on one occasion.

That compares to 54 percent of nonpregnant women in the United States who say they’ve had at least one drink the past month and 18 percent who admit to binge drinking in the past 30 days.

The report indicates that the rates have not changed much since

Read More: The Facts on Fetal Alcohol Syndrome »

CDC Recommends No Drinking During Pregnancy

In 2005, the Surgeon General of the United States urged pregnant women to abstain from any alcohol use.

This included women who are trying to become pregnant or think they might be in the early stages of pregnancy.

The announcement updated a 1981 decree by the Surgeon General’s office urging women to limit their alcohol intake.

CDC officials say any alcohol consumed during any stage of pregnancy can potentially damage an unborn child and lead to

Those disorders range from learning disabilities to small head size and low body weight to vision limitations to emotional problems.

“There is no safe amount, no safe time, and no safe type of alcohol to drink during pregnancy,” Cheryl Tan, MPH, an epidemiologist with the CDC’s National Center on Birth Defects and Developmental Disabilities, told Healthline. “It’s just not worth the risk.”

Tan said the CDC is also trying to get the word out to healthcare providers to advise women who are pregnant or are trying to get pregnant to avoid alcohol.

Her recommendations are echoed by Dr. Patricia Robertson, a specialist in high-risk obstetrics at the University of California, San Francisco.

Robertson told Healthline evidence has been steadily growing since she started practicing in 1976 that drinking any alcohol during pregnancy puts the fetus at risk.

“I work in a unit with 20 physicians and we don’t agree on everything, but we all agree there should be no drinking during pregnancy,” she said.

Read More: The Facts on Healthy Pregnancy »

Some Say an Occasional Drink Is OK

There are a few sources that say an occasional drink during the second and third trimesters may be all right.

A concluded that light to moderate drinking during the latter stages of pregnancy was not a risk factor for child behavioral problems later in life.

The researchers tracked 10,500 children through grade school. Most of the mothers abstained from drinking during pregnancy, but one in five had one or two units of alcohol a week. Researchers said testing done at age 5 on the children whose mothers drank showed no delays in emotional, behavioral, or cognitive development.

Emily Oster, a Harvard-trained economist, wrote in her book, Expect Better: Why Conventional Pregnancy Wisdom is Wrong — and What You Really Need to Know, that there wasn’t anything wrong with an occasional drink during pregnancy.

Her basic message urges women to “take back their pregnancy.” However, her recommendations have been criticized in many corners.

Tan and Robertson both noted that a baby’s brain is developing during an entire pregnancy and that alcohol consumed by the expectant mother travels to a fetus through the placenta. Alcohol is categorized as a teratogen, a substance that can interrupt the normal growth of an embryo.

“Why would you want to impair you baby’s developing system?” said Robertson.

With that in mind, Tan and Robertson agree the 10 percent of women who still do drink during pregnancy is too high.

“One in ten is still too many,” said Tan.

Read More: Here’s What Happens When You Quit Drinking Alcohol for a Month »