Key Findings: Lifestyle During Pregnancy Study

Low to Moderate Alcohol Use During Pregnancy and the Risk of Specific Neurodevelopmental Effects in Five Year-Old Children

The Lifestyle During Pregnancy Study examined a subset of five-year-old children and their mothers from the Danish National Birth Cohort. The study investigated three neurodevelopmental effects in five-year-old children whose mothers reported drinking low to moderate amounts of alcohol^* during pregnancy. The purposes of this study, funded in part by CDC through a cooperative agreement, were to (1) gain a better understanding of how different amounts of alcohol can affect child development, (2) improve study methods to better understand the less obvious effects of low to moderate prenatal alcohol use, and (3) address some of the challenges with measuring subtle effects of drinking alcohol on neurodevelopment.

Main findings from this study:

BJOG: An International Journal of Obstetrics and Gynaecology has published five papers from the Lifestyle During Pregnancy Study which examined three specific neurodevelopmental outcomes in five-year-old children whose mothers reported drinking low to moderate amounts of alcohol during pregnancy. The findings, specific to the outcomes of intelligence, attention, executive function^†, and in combination with each other, were as follows:

• Drinking low to moderate amounts of alcohol during pregnancy did not predict intelligence scores and was not associated with decreased intelligence scores for five-year-old children. In addition, no association was found between binge drinking early in pregnancy and child intelligence except that women who binged in gestational weeks 1-2 were less likely to have children with low IQ. This latter finding has not been reported previously in the literature.
• Drinking low to moderate amounts of alcohol during pregnancy was not associated with attention skills for five-year-old children. However, there was an association between drinking nine or more drinks per week and low overall attention scores. No consistent associations were observed between binge drinking and attention test scores.
• Drinking low to moderate amounts of alcohol during pregnancy was not associated with executive functioning in five-year-old children. Only weak and inconsistent associations between binge drinking and executive functions were observed.
• Drinking low to moderate amounts of alcohol or any binge drinking during early to mid-pregnancy was not associated with five-year-old children’s intelligence, attention, and executive function, when studied in combination with each other.

Generally, findings from this study suggest no serious effects on select neurodevelopmental functions in five-year-old children whose mothers drink low to moderate amounts of alcohol in pregnancy. This study investigated just a few of the possible outcomes of low to moderate alcohol use during pregnancy. Other studies have shown that drinking alcohol at these levels during pregnancy is associated with miscarriage, stillbirth, preterm delivery, and sudden infant death syndrome (SIDS).¹ For example, a recent study of the same study population investigated here, the Danish National Birth Cohort, found that even low amounts of alcohol consumption during early pregnancy substantially increased the risk of miscarriage.² Further, drinking alcohol during pregnancy has consistently been shown to result in lifelong disorders in children, known as fetal alcohol spectrum disorders (FASDs).³

It is important to note that this study is one piece of information in weighing the effects of drinking alcohol during pregnancy on specific neurodevelopmental outcomes. While these articles add to the body of literature in this area, more work is needed to develop better measures to assess the complex effects of drinking alcohol during pregnancy. In addition, further studies on a range of contributing factors such as genetics or nutrition are also needed.

Preventing alcohol-exposed pregnancies and FASDs: CDC activities

CDC has been involved in fetal alcohol spectrum disorders (FASDs)-related activities since 1991. CDC plays a major role in monitoring alcohol use among women of reproductive age and the prevalence of fetal alcohol syndrome (FAS), developing and testing multiple approaches to prevent FASDs, developing interventions for individuals and families living with FASDs, improving how FASDs are diagnosed, and improving awareness of and knowledge about prenatal alcohol exposure among health care providers and the general public:

• CDC is engaged in a series of prevention activities to reduce alcohol-exposed pregnancies.
• CDC tracks alcohol use among women of reproductive age in the United States and the prevalence of FAS in several areas.
• CDC engages in activities to increase awareness of and knowledge about FASDs among health care providers and women of reproductive age.
• CDC collaborates with multiple partners on various FASD-related issues.

^*In this study “low” was defined as 1-4 drinks per week, “moderate” as 5-8 drinks per week, and “binge” as 5 or more drinks on an occasion. In the scientific literature, at the time of this study, alcohol binge drinking during pregnancy was defined as 5 or more drinks on a single occasion. It should be noted that in 2006, in the U.S., the definition of binge drinking for women was changed to 4 or more drinks on a single occasion. A standard drink in Denmark is 12 grams of alcohol; in the U.S., a standard drink is 14 grams of alcohol.

^†Executive functioning is an overarching term that encompasses several higher-level organizational, planning, memory and attention skills. Behaviors that might indicate a deficit in executive functioning include poor organization, planning, or strategy use; concrete thinking; lack of inhibition; difficulty grasping cause and effect; inability to delay gratification; working memory problems, difficulty following multistep directions; difficulty changing strategies or thinking of things in a different way; poor judgment; and inability to apply knowledge to new situations.

More Information

To learn more about alcohol use during pregnancy, please visit https://www.cdc.gov/ncbddd/fasd/alcohol-use.html.

For more information about fetal alcohol spectrum disorders and CDC’s activities in this area, please visit www.cdc.gov/fasd.

References:

1. Bailey BA, Sokol RJ. Prenatal alcohol exposure and miscarriage, stillbirth, preterm delivery, and sudden infant death syndrome. Alcohol Research & Health;34(1):86-91.
2. Andersen AMN, Andersen PK, Olsen J, Grønbæk M, Strandberg-Larsen K. Moderate alcohol intake during pregnancy and risk of fetal death. International Journal of Epidemiology. 2012;41(2):405-413.
3. Sokol RJ, Delaney-Black V, Nordstrom B. Fetal alcohol spectrum disorder. Journal of the American Medical Association. 2003;290(22):2996-2999.

Key Findings References:

• Falgreen Eriksen H-L, Mortensen EL, Kilburn T, Underbjerg M, Bertrand J, Støvring H, Wimberley T, Grove J, Kesmodel US. The effects of low to moderate prenatal alcohol exposure in early pregnancy on IQ in 5- year-old children. BJOG 2012; DOI: 10.1111/j.1471-0528.2012.03394.x
• Kesmodel US, Falgreen Eriksen H-L, Underbjerg M, Kilburn TR, Støvring H, Wimberley T, Mortensen EL. The effect of alcohol binge drinking in early pregnancy on general intelligence in children. BJOG 2012; DOI: 10.1111/j.1471-0528.2012.03395.x  
• Underbjerg M, Kesmodel US, Landrø NI, Bakketeig L, Grove J, Wimberley T, Kilburn TR, Sværke C, Thorsen P, Mortensen EL. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on selective and sustained attention in 5-year-old children. BJOG 2012; DOI: 10.1111/j.1471-0528.2012.03396.x
• Skogerbø Å, Kesmodel US, Wimberley T, Støvring H, Bertrand J, Landrø NI, Mortensen EL. The effects of low to moderate alcohol consumption and binge drinking in early pregnancy on executive function in 5-year-old children. BJOG 2012; DOI 10.1111/j.1471-0528.2012.03397.x
• Kesmodel US, Bertrand J, Støvring H, Skarpness B, Denny CH, Mortensen EL, and the Lifestyle During Pregnancy Study Group.* The effect of different alcohol drinking patterns in early to mid pregnancy on the child’s intelligence, attention, and executive function. BJOG 2012; DOI: 10.1111/j.1471-0528.2012.03393.x

*The Lifestyle During Pregnancy Study Group

Bakketeig LS, Boyle CA, Cogswell ME, Falgreen Eriksen H-L, Grove J, Kilburn T, Landrø NI, Skogerbø Å, Underbjerg M, Wimberley T