As many (most?) people know nowadays - drinking alcohol during pregnancy can have negative effects on the developing baby. Drinking a lot of alcohol can result in fetal alcohol syndrome, but drinking smaller amounts (frequently or binge drinking now and then) can also have negative effects, even though not as severe. The effects from alcohol are called fetal alcohol spectrum disorders - because the effects are along the spectrum from major to minor effects. Currently they're called fetal alcohol syndrome, partial fetal alcohol syndrome, or alcohol related neurodevelopmental disorder. Effects are generally determined by the child's facial features, physical growth, neurobehavioral development, and prenatal alcohol exposure (esp. by interviewing the mother).
A recent study tried to determine how common are fetal alcohol spectrum disorders in the United States. The researchers screened 6639 first grade children in 4 communities from different areas of the US, and fully evaluated about 3000 children for fetal alcohol spectrum disorders. They found that the disorders ranged from 1.1% to 5% in the communities studied - and they felt that this is a conservative estimate. Interestingly, almost all of these newly diagnosed children had not been diagnosed with fetal alcohol spectrum disorders before the study. So it's easy to miss, and to misdiagnose- thus a "hidden problem".
How to avoid this problem? Don't drink alcohol during pregnancy. But unfortunately many women don't realize that they are pregnant in the first trimester, especially if the pregnancy is unplanned. The Centers for Disease Control (CDC) says on its site (official advice) that women should: "Stop drinking alcohol if they are trying to get pregnant or could get pregnant." What about men who drink alcohol and then conceive a child? There is also some research (mainly animal research) that alcohol can have negative effects on the father's sperm and the resulting fetus. Not fetal alcohol spectrum disorders, but perhaps other health effects which are still being determined.
From journalist Pam Belluck's article at the NY Times: Far More U.S. Children Than Previously Thought May Have Fetal Alcohol Disorders
More American children than previously thought may be suffering from neurological damage because their mothers drank alcohol during pregnancy, according to a new study. The study, published Tuesday in the journal JAMA, estimates that fetal alcohol syndrome and other alcohol-related disorders among American children are at least as common as autism. The disorders can cause cognitive, behavioral and physical problems that hurt children’s development and learning ability.
The researchers evaluated about 3,000 children in schools in four communities across the United States and interviewed many of their mothers. Based on their findings, they estimated conservatively that fetal alcohol spectrum disorders affect 1.1 to 5 percent of children in the country, up to five times previous estimates. About 1.5 percent of children are currently diagnosed with autism.
The range of fetal alcohol spectrum disorders (also called FASDs) can cause cognitive, behavioral and physical difficulties. The most severe is fetal alcohol syndrome, in which children have smaller-than-typical heads and bodies, as well as eyes unusually short in width, thin upper lips, and smoother-than-usual skin between the nose and mouth, Dr. Chambers said. A moderate form is partial fetal alcohol syndrome. Less severe is alcohol-related neurodevelopmental disorder, in which children have neurological but not physical characteristics and it is known that their mothers drank during pregnancy.
Then there is the stigma that often makes mothers reluctant to acknowledge alcohol consumption. “When you identify a kid with FASD, you’ve just identified a mom who drank during pregnancy and harmed her child,” said Susan Astley, director of the Fetal Alcohol Syndrome Diagnostic and Prevention Network at the University of Washington, who was not involved in the study. While Dr. Astley, a longtime expert in the field, said she admired the researchers’ hard work, she said the reliability of the study’s numbers was hampered by several factors. For example, only 60 percent of eligible families in the schools allowed their children to be evaluated and more than a third of those children’s mothers declined to answer questions about drinking during pregnancy.
The authors of the study, which was funded by the National Institute on Alcohol Abuse and Alcoholism, acknowledged the study’s limitations and tried to partly compensate by providing a conservative estimate (of 1.1 percent to 5 percent) that is likely low and another estimate (of 3.1 percent to 9.9 percent) that is likely high. Dr. Chambers also said the results might not generalize across the country because although the four communities were diverse, they did not include a large, high-poverty urban area or certain rural or indigenous communities that struggle with high rates of alcoholism. The locations, which are not named in the publication, include small-to-midsize cities in the Midwest and Rocky Mountains, a Southeast county and a Pacific Coast city the authors identified in interviews as San Diego. [Original study.]