Agreement of umbilical cord drug and cotinine levels with maternal self-report of drug use and smoking during pregnancy

Abstract

We read with interest the paper by Wright TE et al. 1 and we would like to add some conclusions reached by our group after a clinical research evaluating prenatal exposure to tobacco smoke by cotinine in cord blood. 2 Prenatal tobacco exposure has been usually assessed using selfreported maternal questionnaire. Difficulties in differentiating passive tobacco exposure from active smoking (among there reluctant to admit active smoking or unconscious of passive exposure) have prompted the use of specific biomarkers to prevent bias in self-reported questionnaires. 3,4 Nicotine and its main metabolite (cotinine) have been used as biomarkers for second-hand smoke in conventional (blood and urine) and non-conventional matrices (saliva, meconium and hair). 5 Cotinine presents a longer biological half-life than nicotine, and it is considered the best biochemical marker to differentiate between active and passive tobacco exposure. Moreover, the levels of cotinine have been found to be directly related with daily cigarette consumption. 6 We believe that the accurate assessment of fetal exposure to smoking through the objective measure of a biomarker could be of major importance in cohort studies, in which the ultimate goal is monitoring passive exposure to tobacco smoke and the investigation of the effects of prenatal and postnatal environmental exposures to pollutants, including tobacco smoke. Cord serum cotinine appeared to be an adequate biomarker due to its ability to be associated with levels of active smoking, levels of passive maternal exposure to smoking, and to neonatal effects such as birth weight. Cord serum cotinine is able to discriminate active smoking from exposure to environmental tobacco smoke and exposure from non-exposure. Finally, the ease of collection and processing of cord blood advocate for the extension of the use of cord serum cotinine as a biomarker of prenatal exposure to smoking. 2 Cotinine cord blood is the most sensitive and less invasive measure of prenatal second-hand smoke in newborns and usually has a good correlation with self-reported smoking parents. 2,7,8 Conflict of interest The authors declare no conflict of interest. Agreement of umbilical cord drug and cotinine levels with maternal self-report of drug use and smoking during pregnancyJournal of Perinatology (2012) 32, 156-157; doi:10.1038/jp.2011 We thank Garcia-Algar et al. 1 for their interest in our recent work. We agree with their conclusions that cord serum is a reliable indicator of smoke exposure, both direct and environmental. We specifically developed our method assaying umbilical cord tissue to assess smoke exposure when cord serum is not available, especially for histological comparisons of placental pathology.

Detection of opioids in umbilical cord lysates: an antibody-based rapid screening approach

“…If testing occurred shortly (minutes to hours) after ingestion, results would initially be several fold higher than true as 6-acetyl morphine is produced quickly, but after this, results would be under predictive of ingestion as the poorly detected glucuronides become more abundant. Despite this, relative levels of quantification can be detected as "high" or "low", an improvement on the "yes" or "no" previously reported (Montgomery et al 2006;Wright et al 2011).…”

“…Upon request, individual pieces of umbilical cord tissue (0.2 -0.5 g) were cut from frozen cords and shipped on dry ice to the University of British Columbia, where they were stored at −80°C until processing to lysates. UCs (n=101) were processed to lysates as previously described (Wright et al 2011). Briefly, tissues were thawed and mechanically homogenized using a Tissue Tearor™ (Daigger Scientific, Vernon Hills, IL, USA) in 1:3 (w:v) Tris-HCl buffer containing 5 mM MgCl 2 and 2 mM PMSF.…”

The Prevalence of Prenatal Opioid and Other Drug Use in Utah

“…Studies have documented that the prevalence of maternal self-report of prenatal illicit drug use can be significantly lower than that determined by drug screening of umbilical cord or meconium samples. 7,8 Umbilical cord analysis detects actual exposure and has been shown to perform as well as meconium in assessing fetal drug exposure from approximately week 18 of gestation. 9,10 Second, the SAMSHA survey data are based on reported nonmedical use of prescription pain medication.…”

Development and validation of a liquid chromatography–tandem mass spectrometry method for the determination of nicotine and its metabolites in placenta and umbilical cord

“…Although these methods have been applied for the analysis of authentic specimens, full method validation data were not reported . Moreover, the reported investigations either included the detection of only nicotine and cotinine, or just cotinine ; only 1 article included nicotine, cotinine, and OH‐cotinine, as well as nornicotine and anabasine …”

“…To our knowledge, this is the first study to measure nicotine, cotinine, and hydroxycotinine (OH‐cotinine) levels in both placenta and umbilical cord tissue. Three methods have been published for the determination of tobacco biomarkers in placenta, and 2 in umbilical cord . Although these methods have been applied for the analysis of authentic specimens, full method validation data were not reported .…”