In utero drug and alcohol exposure in infants born to mothers prescribed maintenance methadone.

AIMS: To describe the prevalence of in utero alcohol and illicit drug exposure in infants born to mothers prescribed methadone in pregnancy, and to compare the accuracy of maternal interview with infant toxicology.

METHODS

Urine and meconium samples were collected from 56 infants born to mothers prescribed methadone during pregnancy and a confidential interview conducted soon after delivery. Samples were screened for drugs of misuse and meconium samples analysed for the presence of fatty acid ethyl esters (FAEEs) to detect prenatal alcohol exposure.

RESULTS

91% of infants had been exposed to illicit drugs in utero, including opiates (73%), benzodiazepines (70%) and cannabinoids (59%). 47% of infants had elevated FAEEs. Meconium was more sensitive at detecting in utero drug exposure than urine toxicology (p<0.01 for opiates, benzodiazepines, cannabinoids) or maternal interview (p=0.03 for opiates, p<0.01 for cannabinoids).

CONCLUSIONS

The majority of infants born to mothers prescribed methadone during pregnancy are exposed to polysubstance misuse, and almost one-half additionally exposed to excess alcohol.