Screening for illicit drug use in a military obstetric population

The purpose of our investigation was to determine the prevalence of illicit drug use within our socioeconomically heterogeneous obstetric population, in order to assess the need for institution of universal screening. Five hundred consecutive new obstetric registrants had urine collected for routine culture. Following removal of a small aliquot of urine for culture, the samples were sent to the Armed Forces Institute of Pathology, Division of Forensic Toxicology. Each specimen was screened for the presence of alcohol, cocaine metabolites, cannabinoids, opiates, and amphetamines using fluorescent polarization immunoassay techniques. All positive screening tests were confirmed by gas chromatography mass spectrometry. Thirty samples were either lost in processing or of insufficient quantity to test. Five of the 470 samples (1.06%) tested were positive. One subject was taking prescription narcotics, so the correlated prevalence was 0.85%. Three tested positive for tetrahydrocannabinol and two for opiates. Analysis of our data demonstrates that our obstetric population has a significantly lower prevalence of illicit drug use than other populations reported previously (P less than .01). We recommend that each institution providing obstetric services determine its specific prevalence of illicit drug use.