Researchers from France and the UK who reviewed the scientific literature found that drinking alcohol during pregnancy was linked to a significantly higher risk of children developing a rare form of leukemia called acute myeloid leukemia (AML).

You can read about the study, led by Dr Paule Latino-Martel, research director at the Research Center for Human Nutrition in France, in the online May issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Leukemia is the most common cancer in children, and although we don't know much about its causes, many scientists believe it results from an interaction between genes and environment, and drinking alcohol while pregnant has been raised as a possible candidate for the latter.

For the study, Latino-Martel conducted a systematic review and meta-analysis of published studies to find all the already established links between maternal alcohol consumption during pregnancy and childhood leukemia. A meta-analysis is a way of pooling and re-analyzing data from several studies as if they had come from one large one.

They found 21 case-control studies where they could analyze links between diagnosis of leukemia in children born to mothers who answered yes or no to a question about alcohol consumption during pregnancy.

They also looked at other factors such as type of leukemia, child's age at diagnosis, type of alcoholic beverage and which trimester of pregnancy the mother drank alcohol, if she did.

The results showed: A statistically significant link between maternal alcohol drinking during pregnancy (yes versus no) and diagnosis of AML in the children (odds ratio OR 1.56 with 95 per cent confidence interval CI ranging from 1.13 to 2.15).
No statistically significant link with acute lymphoblastic leukemia (OR 1.10 and 95% CI 0.93-1.29).
For AML, drinking an extra drink a week was linked to a 24 per cent increase in risk (OR 1.24, 95% CI 0.94-1.64).
Some heterogeneity between studies (this measures design consistency across studies: high heterogeneity means you should be careful about drawing overall conclusions from a pooled analysis).
The link between AML and drinking alcohol during pregnancy was observed for diagnoses made at age 0 to 4 years (OR 2.68, 95% CI 1.85-3.89) in 5 studies with no heterogeneity. The researchers concluded that:

"The results of case-control studies indicate that maternal alcohol consumption during pregnancy is associated with a significantly increased risk of AML in young children."

According to figures published in 1998, the global annual rate of childhood leukemia varies from 20 to 60 cases per million, with more affluent countries generally having higher rates than less developed countries.

Dr Julie Ross, director of the division of pediatric epidemiology and clinical research at the University of Minnesota, was not involved with the study, but is a member of the editorial board of the journal that published it.

She said in a statement that there are around 700 childhood cases of AML a year in the US:

"It's quite rare, so we want to be careful about worrying parents too much," she urged.

However, she agreed that the findings strengthen the case for recommending women abstain from alcohol during pregnancy.

Latino-Martel said even though the current recommendation is that women should not drink alcohol when pregnant:

"... alcohol consumption during pregnancy is 12 percent in the United States, 30 percent in Sweden, 52 percent in France, 59 percent in Australia and 60 percent in Russia."

"Maternal Alcohol Consumption during Pregnancy and Risk of Childhood Leukemia: Systematic Review and Meta- analysis."
Paule Latino-Martel, Doris S.M. Chan, Nathalie Druesne-Pecollo, Emilie Barrandon, Serge Hercberg, and Teresa Norat.
Cancer Epidemiol Biomarkers Prev, May 2010 19:1238-1260.
DOI:10.1158/1055-9965.EPI-09-1110

Source: AACR, Children with Leukemia (UK).

: Catharine Paddock, PhD