Ursitti F, Klein J, Koren G
Department of Pediatrics, Hospital for Sick Children, Toronto, Ont., Canada.
Biol Neonate. 1997;72(6):345-51. doi: 10.1159/000244504.
There has been a steady increase in the number of newborns affected by maternal drug use. Cocaine and its metabolites cross the placenta and have been routinely measured in neonatal urine; however, due to the short half-life of the drug many exposed fetuses have negative urine tests. We have developed a neonatal hair test for measuring cocaine and its metabolites by radioimmunoassay. Since the validation of this test we prospectively evaluated its clinical utility by physicians, hospital nurseries and social welfare agencies who requested neonatal hair analysis to verify clinical suspicion of maternal cocaine use during pregnancy.
The objective of the present research was to establish the sensitivity of the hair test in validating clinical suspicion of in utero exposure to cocaine in the presence of negative urine test.
We hypothesized that the use of the hair test in cases of clinical suspicion but negative urine test will yield a substantially higher rate of positivity than expected in the general population.
Between October 1991 and April 1995 we prospectively analyzed a total of 192 neonatal hair samples to confirm clinical suspicions of intrauterine exposure to cocaine. Of these, 10 did not have sufficient hair to analyze for cocaine metabolites.
Fifty-five (30%) of the remaining 182 were positive for cocaine metabolite. This rate was 5.5-fold higher than the 5.5% found by us in a population-based research study in three nurseries in Toronto (p < 0.001), thus documenting the efficiency of this test in confirming clinical suspicions of fetal exposure to cocaine. Benzoylecgonine concentrations in this cohort were 2-fold higher than among positive cases in a previous population-based screening study (p = 0.0001) indicating that when clinical suspicions prompted physicians to test neonatal hair, they identify a subgroup of heavy cocaine users, who are probably at higher perinatal risks.
受母亲药物使用影响的新生儿数量一直在稳步增加。可卡因及其代谢产物会穿过胎盘，并且已常规在新生儿尿液中进行检测；然而，由于该药物半衰期短，许多受影响的胎儿尿液检测呈阴性。我们开发了一种通过放射免疫测定法测量可卡因及其代谢产物的新生儿毛发检测方法。自该检测方法验证以来，我们由医生、医院托儿所和社会福利机构对其临床效用进行了前瞻性评估，这些机构要求进行新生儿毛发分析以核实对孕期母亲使用可卡因的临床怀疑。
本研究的目的是确定在尿液检测呈阴性的情况下，毛发检测在验证临床怀疑子宫内接触可卡因方面的敏感性。
我们假设在临床怀疑但尿液检测呈阴性的情况下使用毛发检测，其阳性率将大大高于一般人群的预期。
在1991年10月至1995年4月期间，我们前瞻性地分析了总共192份新生儿毛发样本，以确认对子宫内接触可卡因的临床怀疑。其中，10份没有足够的毛发来分析可卡因代谢产物。
其余182份样本中有55份（30%）可卡因代谢产物呈阳性。该比率比我们在多伦多三个托儿所进行的一项基于人群的研究中发现的5.5%高出5.5倍（p < 0.001），从而证明了该检测在确认胎儿接触可卡因的临床怀疑方面的有效性。该队列中的苯甲酰爱康宁浓度比之前一项基于人群的筛查研究中的阳性病例高出2倍（p = 0.0001），这表明当临床怀疑促使医生检测新生儿毛发时，他们识别出了一组重度可卡因使用者，这些人可能围产期风险更高。
