众所周知中，孕妇饮酒有损于胎儿发育，如妊娠期饮酒的女性生下的宝宝常常体重较轻、身材较小、头颅较小、鼻梁较低和上唇较薄，甚至可诱发流产或死产等。最近，有学者发表了“孕妇何时饮酒对胎儿发育之影响最大”的论文。研究人员将10个月的妊娠期分为三个阶段（每个阶段约3个月＋1周）进行观察，结果发现“孕妇于妊娠第一阶段，即前3个月之后半段饮酒对胎儿之伤害最大”。研究人员同时指出，关于孕妇饮酒，他们无法给出一个安全剂量，因为每个人对待酒精之代谢能力与反应均不相同，故要消除酒精对胎儿之影响，准妈妈们最好的办法就是不喝酒。更多资讯，请参阅全文。

Drinking Late in First Trimester May Be Most Hazardous

But no alcohol use is safe during pregnancy, study finds

TUESDAY, Jan. 17 (HealthDay News) -- It's known that drinking during pregnancy leaves babies vulnerable to a spectrum of abnormalities called fetal alcohol syndrome. Now, a new study pinpoints the latter half of the first trimester as a critical time in the development of some of the syndrome's most telling physical characteristics.

Study authors also stressed that their research illustrates there is no safe amount of drinking during pregnancy, since the amount of drinking that produced these features in infants varied from woman to woman.

"The fact that we didn't find a safe threshold is important," said study author Christina Chambers, an associate professor of pediatrics and family and preventive medicine at the University of California, San Diego. "Not every child of women who drink even very heavily has all the features, so there are certain susceptibility factors that we don't know."

The study appears online Jan. 16 ahead of print publication in the April issue of the journal Alcoholism: Clinical & Experimental Research. The authors say it is one of the first to examine the impact of quantity, frequency and timing of alcohol exposure on the condition.

Thought to affect about 1 percent of the American population, fetal alcohol syndrome can result in physical, behavioral and learning problems. People with the syndrome may have abnormal facial features, such as a smooth ridge between the nose and upper lip, small head size, unusually small-set eyes and shorter-than-average height.

The 992 women in the study were enrolled in the California Teratogen Information Service and Clinical Research Program between 1978 and 2005, which provided confidential risk assessments for any potential toxin exposures during pregnancy. 　　　Every three months during the remainder of their pregnancies, they were asked about their use of alcohol and other substances, including specific dates of use, drinks per day, number of binge episodes and maximum number of drinks.

Information about their babies' development was collected after birth, and each newborn was then examined by a dysmorphologist, a specialist in structural birth defects, to look for evidence of fetal alcohol syndrome as well as other conditions.

While higher levels of alcohol exposure were strongly linked to a greater risk of infants born smaller and lighter, with small heads and a smooth ridge between the nose and upper lip, the most significant associations were observed during the second half of the first trimester of pregnancy -- defined as 43 to 84 days after conception.

For every one-drink increase in the daily average number of drinks consumed during this stage of pregnancy, there was a 25 percent higher risk for having a smooth ridge between the nose and upper lip; a 22 percent higher chance of having an abnormally thin upper lip; a 12 percent elevated risk of having a smaller-than-normal head; a 16 percent greater risk of reduced birth weight; and an 18 percent higher chance of reduced birth length.

In addition, the likelihood of shorter birth length was associated with drinking in any trimester, the study found.

"There is almost 40 years of research [on fetal alcohol syndrome], but one of the challenges has been determining what are the windows of risk and the patterns in timing and quantity of alcohol use, and this [study] addresses that," said Tom Donaldson, president of the National Organization on Fetal Alcohol Syndrome in Washington, D.C. "This article very clearly demonstrates that risk begins with any use."

Chambers and her colleagues theorized that alcohol exposure in the first six weeks of pregnancy -- when many women don't yet know they're pregnant -- may result in higher miscarriage rates, although the study did not include women who had miscarriages or stillbirths.

SOURCES: Christina Chambers, Ph.D., M.P.H., associate professor, pediatrics, and family and preventative medicine, University of California, San Diego; Tom Donaldson, president, National Organization on Fetal Alcohol Syndrome (NOFAS), Washington, D.C.; April 2012 issue Alcoholism: Clinical & Experimental Research, online, Jan. 16, 2012