“This result is nonsense, I know I didn’t drink”: Women’s responses to hair ethyl glucuronide results indicating alcohol use during pregnancy. A qualitative study

BACKGROUND: Ethyl glucuronide in maternal hair (hEtG) is increasingly used in epidemiological research as a biomarker of alcohol consumption during pregnancy and prenatal alcohol exposure, as it provides objective, long-term evidence of alcohol consumption. OBJECTIVES: To understand postpartum women's perceptions of and reactions to hEtG results indicating alcohol use during pregnancy. MATERIAL AND METHODS: The study involved 150 postpartum women and their newborns. Maternal hair samples were analyzed for hEtG concentrations using gas chromatography-tandem mass spectrometry (GC-MS/MS). Data included survey responses on self-reported alcohol use during pregnancy and medical record information on the course of pregnancy and neonatal health. Two years later, participants were offered the opportunity to receive their hair analysis results, and their reactions were qualitatively analyzed. RESULTS: The hEtG analysis indicated alcohol consumption at some point during pregnancy in 50% of the women. Among these, 10% had hEtG concentrations consistent with excessive alcohol use. Self-reported data indicated alcohol use before pregnancy recognition in 32% of participants and alcohol use when knowing about pregnancy in only 3%. There was no clear association between self-reports and hEtG results. At the 2-year follow-up, when informed of their positive hEtG results, participants expressed a range of reactions grouped into 7 themes: disengagement and indifference; reassurance based on the child's health; rejection and denial; surprise and confusion; seeking alternative explanations; concerns about research validity; and acceptance or ambiguous acknowledgment. CONCLUSIONS: Maternal hair testing is a valuable tool for investigating prenatal alcohol exposure; however, positive results are frequently questioned or denied by participants. While discussions often focus on possible alternative explanations for elevated hEtG levels, such as external contamination, the most plausible explanation remains actual alcohol consumption during pregnancy. Nonetheless, the stigma associated with such behavior and/or fear of legal or social consequences may lead to persistent denial, highlighting the challenges of interpreting and communicating biomarker results in sensitive contexts.