- Maternal smoking has been associated with childhood asthma.
- A new study examines if those children born to mothers who consume alcohol during pregnancy have a greater risk of hospitalization for asthma.
- Findings indicate no causal link between alcohol consumption during pregnancy and asthma during childhood.
Asthma is a major public health problem throughout the world. In the United States alone, according to the National Heart, Lung and Blood Institute, asthma affects more than 20 million Americans. In the year 2000, nearly 5,000 Americans died due to asthma-related problems. Researchers in the May issue of Alcoholism: Clinical & Experimental Research investigate if those children born to mothers who consume alcohol during pregnancy have a greater risk of hospitalization for asthma. Their findings indicate there is no causal link between alcohol consumption during pregnancy and asthma during childhood.
"The idea to study the association between maternal alcohol intake and childhood asthma is primarily based on the current knowledge that asthma prevalence has rapidly increased on a global basis," said Wei Yuan, assistant director of the Shanghai Institute of Planned Parenthood Research. "One theory, the 'hypothesis of programming,' looks at the fetal origins of diseases; and we thought this might also provide a chance to examine any early environmental factors for asthma. In addition, it makes sense to study the association between maternal alcohol intake and childhood asthma because of an increase of alcohol intake among young women, and the biological plausibility of the fetal effects of alcohol on the immunological components of asthma."
Yuan and his colleagues gathered data on 10,440 single-born infants who were born at 36 weeks of gestation or later to mothers attending midwife centers between April 1984 and April 1987 in Denmark. Mothers completed a questionnaire regarding lifestyle and socio-economic factors, including alcohol consumption. The Danish Hospital Discharge Registry was used, up to the end of 1996, to determine if any of these children experienced later hospitalization with a discharge diagnosis of asthma.
The majority of pregnant women (81.5%) drank at least some alcohol during pregnancy, but only a few (2.1%) consumed 120 grams or more per week. Only 307 of the children were hospitalized/discharged with a diagnosis of asthma a minimum of once during the first 12 years of their lives. After adjusting for maternal socio-economic, dietary and other lifestyle factors, the results indicate that children whose mothers drank alcohol during pregnancy did not have a greater risk of hospitalization for asthma compared with the children of mothers who reported no alcohol consumption during pregnancy.
"Although the study findings do not provide evidence that maternal alcohol intake during pregnancy increases the risk of childhood asthma," said Yuan, "the conclusion may be limited by a number of limitations of the study, such as the inability to examine the effects of very high prenatal alcohol exposure, as we know that many fetal effects of alcohol are observed at a dosage of more than 100 or 120 grams per week."
Yuan also said that these findings should not be interpreted as an indication of a "safe" level of alcohol consumption during pregnancy, as many intangibles remain to be determined by researchers.
"While the reader can see that this dosage of alcohol does not appear to increase the risk of childhood asthma, they must consider other health problems that may be linked to a similar dose of alcohol," he said. "Maternal alcohol intake has many public and health concerns other than asthma. In addition, the timing of alcohol exposure and its subsequent effects on fetal growth remain an essential topic of research."
Alcoholism: Clinical & Experimental Research (ACER) is the official journal of the Research Society on Alcoholism and the International Society for Biomedical Research on Alcoholism. Co-authors of the ACER paper, "Prenatal maternal alcohol consumption and hospitalization with asthma in childhood: A population-based follow-up study" were: Henrik Toft Sørensen of the Department of Clinical Epidemiology at Aarhus and Aalborg University Hospitals in Denmark; and Olga Basso and Jørn Olsen of the Danish Epidemiology Science Centre at the University of Aarhus. The study was funded by the Medical Research Council of Denmark, the Western Danish Research Forum for Health Sciences, and the Danish National Research Foundation.