Testing Newborns for Exposure to Alcohol During Pregnancy
Fetal alcohol spectrum disorder.
Reprinted from CMAJ 25-Nov-03;169(11): p. 1184 with permission.
© 2003 Canadian Medical Association.
The presence of a biomarker in a newborn baby’s meconium ― the first bowel movement ― may determine whether a mother drank alcohol during her pregnancy.
The biomarkers are metabolic by-products of alcohol called fatty acid ethyl esters (FAEEs). FAEEs provide a biological record of prenatal alcohol exposure during the second and third trimesters since meconium begins to form during the 13th week of pregnancy and continues to accumulate until birth.[1] Testing for FAEEs at birth may help identify children who are at risk for fetal alcohol spectrum disorder (FASD). Alcohol consumption during the first trimester, which can also negatively affect fetal development,[2] is not detected by meconium testing.
Fetal Alcohol Spectrum Disorder (FASD)
FASD encompasses a range of physical, mental, and behavioural effects due to prenatal alcohol exposure. Secondary disabilities associated with FASD include mental health problems, disruptions in schooling, employment problems, criminal behaviour, and alcohol or drug problems.[3]
FASD is difficult to diagnose because it requires confirmation of heavy maternal drinking, which is under-reported because women are reluctant to admit to risky behaviour during pregnancy. There are currently no specific laboratory markers for diagnosing FASD.[1]
Benefits of Early Diagnosis
Early diagnosis of FASD is associated with better long-term outcomes.[1,3] Targeted interventions in childhood can reduce the risk for later secondary disabilities.[3,4] The diagnosis of FASD may also help prevent alcohol use during subsequent pregnancies by providing high-risk mothers with counselling and education.[2]
Prevalence of Alcohol Use During Pregnancy
An estimated 1% of infants show some prenatal alcohol-related damage.[2,3] In Canada, lifetime costs for additional education, disability payments, and health care for one person with FASD have been estimated at more than $800,000.[2]
Evidence
In published studies, the sensitivity of the meconium test (to correctly identify babies that have been exposed to alcohol) ranges from 26.9%[4] to 100%.[3] Its ability to truly identify those who have not been exposed to alcohol ranges from 96.8%[4] to 98%.[3] Variation could be due to maternal consumption of small amounts of alcohol in medications or foods, genetic variations in alcohol metabolism, or illness.[1]
Elevated levels of meconium FAEEs have not yet been correlated with adverse outcomes in newborn babies. Studies that monitor infants for several years are needed to determine whether FAEEs in meconium can be used as biomarkers of neurodevelopmental delay due to fetal alcohol effect.[4]
In a recent Calgary study, no association was found between a mother’s self-reported alcohol use during pregnancy and FAEE levels in the meconium of 238 infants.[5] Publication of the study results is pending.
Availability and Cost
The Motherisk lab at Toronto’s Hospital for Sick Children offers the only meconium FAEE testing in Canada. The assay costs C$150. It is not covered by provincial health insurance plans.
References
[1] Bearer CF, et al. Alcohol Res Health 2005;28(1):38-43.
[2] Tough SC, et al. In: Motherisk [database online]. Toronto: Hospital for Sick Children; 2005. Available: http://www.motherisk.org/women/updatesDetail.jsp?content_id=737
[3] Koren G, et al. CMAJ 2003;169(11):1181-5. Available:http://www.cmaj.ca/cgi/content/full/169/11/1181
[4] Ostrea EM, Jr., et al. Alcohol Clin Exp Res 2006;30(7):1152-9.