The measurement of serum estriol (E3) level, monitoring the function of fetoplacental unit, is an important parameter in human pregnancy. 62 healthy women aged 20-37 (mean age 27.1±4.6 years) in third trimester of normal pregnancy were included in the study, and divided into six groups depending on the time of pregnancy. The aim of the present work was to evaluate fetus well-being with use of non-invasive method of free estriol determination in saliva of women in third trimester of normal pregnancy (elaboration of own norms) as well as to determine the correlation between serum and salivary estriol concentrations. Salivary and serum estriol concentrations were determined in all studied women. Saliva and blood were collected between 8 a.m. and 9 a.m. Non-conjugated estriol concentration in serum (uE3) and in saliva (SE3) were measured with radioimmunoassay. There was a significant correlation (r=0.76, p < 0.001) between estriol concentrations in serum and saliva. Percentage proportion of salivary estriol to serum estriol concentration fluctuated between 6.51-9.5%. Normal range of salivary estriol concentration for particular weeks of third trimester of normal human pregnancy was presented.

Keywords: non-conjugated estriol, Saliva, human pregnancy, serum