Monitoring Alcohol Use Among Pregnant Women

A study summary of 250 dried blood spot cards from one Midwestern state. 
by Aileen Baldwin, Ph.D., MPH

Despite initiatives to increase awareness, alcohol consumption during pregnancy continues to be a serious public health concern in the United States.  State and nationally-based surveys are currently used to monitor the frequency of drinking during pregnancy to identify groups of women at increased risk and help reduce alcohol-exposed pregnancies by designing prevention programs. Each of these surveys rely on maternal self-report and have both strengths and weaknesses in terms of their ability to subjectively assess alcohol consumption during pregnancy. Estimates from these survey-based studies range from 7% – 30% women who drink alcohol during pregnancy, suggesting that differences in study methods can have an effect on the results.

The Centers for Disease Control and Prevention (CDC) estimates that 1 in 10 (10%) pregnant women use alcohol and 3% report heavy, or binge drinking in the past 30 days.1 The National Survey on Drug Use and Health (NSDUH) report found that 8.5% of pregnant women report alcohol use during the past month and 2.7% reported binge drinking.2 Another report from the multi-state, CDC-sponsored case-control National Birth Defects Prevention Study (NBDPS) found that 30.3% of all women confirm drinking alcohol at some point during pregnancy, and 8.3% binge drank.3

Some limitations of using self-report surveys are that women with severe alcohol use problems may be less likely to participate and under-reporting can occur due to fear of stigmatization and embarrassment. Multiple studies have shown that using objective biological markers of fetal alcohol exposure in newborns in addition to maternal self-report can significantly increase the identified rates of alcohol consumption. Eight studies have examined the frequency of fetal alcohol exposure obtained from maternal self-report and also detection of the alcohol metabolite fatty acid ethyl esters (FAEE) in newborn meconium samples. Using the additional FAEE biomarker information, they found that the prevalence of fetal alcohol exposure was 4.26 times higher than what the prevalence would be if measured by maternal self-report only.4  

As these studies demonstrate, alcohol biomarkers are effective in monitoring maternal alcohol consumption and fetal alcohol exposure. This is a critical public health issue in the United States where survey estimates of drinking among pregnant women suggest that anywhere from 280,000 to 1.2 million babies born each year could have been exposed to alcohol and new studies show that 2 to 5 % of school age children demonstrate the developmental deficits associated with fetal alcohol exposure.5  

Phosphatidylethanol (PEth) is a sensitive and specific biomarker of alcohol use and exposure that has generated significant interest as a potential measurement of fetal alcohol exposure. Once alcohol is consumed, PEth begins to accumulate in red blood cells and can be detected in blood for up to 28 days after the last drinking episode. Given that blood is already routinely collected on filter paper cards for the nearly 4 million babies born each year in the United States, our laboratory worked to develop and validate a highly sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) system to detect PEth in dried blood spots to use as a screening test to identify fetal alcohol exposure in newborns.  

Our laboratory also realized that many state newborn screening programs store the left over newborn blood cards after newborn screening is completed and that screening these stored dried blood spots for PEth could provide a new method for surveying alcohol consumption during late pregnancy. Our goal for this study was to determine the prevalence of fetal alcohol exposure using this direct alcohol biomarker and to compare our results with the prevalence estimates of alcohol use during pregnancy from the state and nationally-based surveys.

To conduct this study, our laboratory worked with the Virtual Repository of Dried Blood Spots (VRDBS), which is a web-based system that allows state public health program personnel to control and manage access to their stored blood spots for newborn screening related research. Upon study approval, the state newborn screening laboratory released 250 de-identified dried blood spots to our laboratory for PEth screening. The dried blood spots had been collected from multiple hospitals across a single Midwestern state in March of 2012.  Of the 250 dried blood spot cards analyzed by our laboratory, 4% of the newborn samples screened positive for PEth, indicating that exposure to maternal alcohol consumption occurred during the last month of pregnancy. These results are in agreement with the national surveys that found approximately 3% of pregnant women reported heavy, or binge drinking during the previous month.  

Monitoring the rates of alcohol use during pregnancy and fetal alcohol exposure is important for identifying at risk populations; targeting prevention and treatment resources; and evaluating the strengths and limitations of the various prevention, and treatment strategies. This study showed that PEth analysis of dried bloods spots can be used for surveillance studies of alcohol consumption during late pregnancy and fetal alcohol exposure using the blood spot samples that are already collected for routine newborn screening. Our laboratory continues to partner with researchers in other states to conduct similar surveillance studies to determine the real scope of this public health problem.  

References

1. Tan, C.H., Denny, C.H., Cheal, N.E., Sniezek, J.E., Kanny, D. (2015). Alcohol use and binge drinking among women of childbearing age – United States, 2011-2013. MMWR Morb Mortal Wkly Rep, 64(37):1042-6. 

2. Results from the 2012 National Survey on Drug Use and Health: Summary of National Findings. Substance Abuse and Mental Health Services Administration, 2013.

3. Ethen, M.K., Ramadhani, T.A., Scheuerle, A.E., Canfield, M.A., Wyszynski, D.F., Druschel, C.M., et al. (2009). Alcohol consumption by women before and during pregnancy. Matern Child Health J., 13(2):274-85. 

4. Lange, S., Shield, K., Koren, G., Rehm, J., Popova, S. (2014). A comparison of the prevalence of prenatal alcohol exposure obtained via maternal self-reports versus meconium testing: a systematic literature review and meta-analysis. BMC Pregnancy Childbirth, 14:127.

5. May, P.A., Baete, A., Russo, J., Elliott, A.J., Blankenship, J., Kalberg, W.O., et al. (2014). Prevalence and characteristics of fetal alcohol spectrum disorders. Pediatrics, 134(5):855-66. 

Dr. Aileen Baldwin is a Research Scientist for USDTL with more than 10 years of experience in biomedical research in laboratory, clinical and public health sectors.