Hair testing applied to the assessment of in utero exposure to drugs: critical analysis of 51 cases of the University Hospital of Verona.

The work discusses the results of hair and urine testing performed in 51 cases of suspected in utero drug exposure handled at the University Hospital of Verona from 2016 to 2022. The day of birth, or the day after birth, urine from mother and newborn (UM and UN) and hair from mother (HM), newborn (HN) and father (HF), if possible, were collected. Urine underwent immunoassay and GC-MS analysis, while hair LC-MS/MS and GC-MS/MS analysis. In 50 out of 51 cases HM and/or HN were available. In 92% of them hair testing resulted positive, often (> 50 % cases) for more than 1 class of substances. The most detected substances were: cocaine, opiates, methadone and cannabinoids. Maternal segmental analysis showed a prevalent decreasing concentration trend during pregnancy in case of positivity for 1 class of substances, while, as expected, a neatly prevalent increasing trend in case of positivity for more than 1 class of substances. In 9 cases, HF were also available, resulting all positive usually for the same classes of substances identified in HM, thus questioning parental responsibility. In 33 cases, urine samples from mother or from newborn were also collected. Of them, 27 cases (82%) tested positive showing a peri-partum drug consumption and then confirming the severity of the addiction. Hair testing showed to be a reliable diagnostic tool to investigate in utero drug exposure because of the possibility to obtain a complete picture of maternal addictive behaviour and family background also thanks to segmental maternal hair analysis and father hair testing.