Estimation of Cutoff Values of Cotinine in Urine and Saliva for Pregnant Women in Poland

Abstract

Setting appropriate cutoff values and the use of a highly sensitive analytical method allow for correct classification of the smoking status. Urine-saliva pairs samples of pregnant women in the second and third trimester, and saliva only in the first trimester were collected. Offline SPE and LC-ESI-MS/MS method was developed in the broad concentration range (saliva 0.4–1000 ng/mL, urine 0.8–4000 ng/mL). The mean recoveries were 3.7 ± 7.6% for urine and 99.1 ± 2.6% for saliva. LOD for saliva was 0.12 ng/mL and for urine 0.05 ng/mL; LOQ was 0.4 ng/mL and 0.8 ng/mL, respectively. Intraday and interday precision equaled, respectively, 1.2% and 3.4% for urine, and 2.3% and 6.4% for saliva. There was a strong correlation between salivary cotinine and the uncorrected cotinine concentration in urine in the second and third trimesters of pregnancy. The cutoff values were established for saliva 12.9 ng/mL and urine 42.3 ng/mL or 53.1 μg/g creatinine with the ROC curve analysis. The developed analytical method was successfully applied to quantify cotinine, and a significant correlation between the urinary and salivary cotinine levels was found. The presented cut-off values for salivary and urinary cotinine ensure a categorization of the smoking status among pregnant women that is more accurate than self-reporting.

Prevalencia de tabaquismo durante el embarazo y factores asociados en Andalucía 2007-2012 (*)

“…No obstante, Greaves 36 hace notar que los límites establecidos en la literatura dan lugar a una "zona gris" o de confusión en la que resulta difí-cil interpretar el estatus de fumadora, sobre todo en lo que se refiere a la exposición pasiva o al consumo esporádico. A la vista de los análisis y resultados obtenidos, un punto de corte >80 ng/ml es suficientemente sensible y específico para detectar un consumo activo, sin embargo resulta elevado para el consumo ligero u ocasional 37 . Por ello, al categorizar a las mujeres gestantes por su nivel de consumo se optó por los intervalos propuestos en la prueba INMULITE 2000 Metabolito de nicotina 22 , aceptando la cifra de 125 ng/ml para la clasificación en fumadoras activas y 20 ng/ml para las no expuestas en una opción por la especificidad.…”

Effect of environmental phthalate exposure on pregnancy duration and birth outcomes

“…The following potential confounders were considered: gestational age (for birth parameters), child gender, maternal active and passive smoking (by the cotinine level in saliva), alcohol consumption during pregnancy, maternal age, height, pre-pregnancy body mass index (BMI), maternal marital, educational and employment status, and parity. Prenatal exposure to tobacco constituents was assessed based on the cotinine level in saliva (collected from the women during the third trimester of pregnancy) at NIOM using the high performance liquid chromatography coupled with tandem mass spectrometry/ positive electrospray ionization (LC-ESI+MS/MS) and isotope dilution method [24].…”

Estimation of Saliva Cotinine Cut-Off Points for Active and Passive Smoking during Pregnancy—Polish Mother and Child Cohort (REPRO_PL)

“…A major advantage of using cotinine rather than nicotine as a biomarker of smoking status is that about 72% of nicotine is converted to cotinine, and the half-life of cotinine averages about 17 h in comparison to 2–3 h in the case of nicotine [2,6,9,10]. Cotinine can be measured in various biological specimens, including plasma, saliva, urine and hair [2,6].…”