Advanced Study on Salivary Progesterone as a Biomarker in Pregnancy

Progesterone is considered as the pregnancy hormone. Progesterone was measured in the saliva of pregnant women at the end of gestation. Samples were collected two times daily (morning and afternoon) during the last two week before the expected delivery date and 2 days after delivery. Analysis was performed using commercial ELISA kits after simple freezing, thawing and centrifugation of the samples. It appeared that during the period before delivery the level of progesterone was in a steady state, until about 2 days before delivery, at which point a rapid decrease could be detected. Immediately after delivery, levels decreased again to non- pregnant values. For comparison reasons, two different ELISA kits were used and evaluated for suitability. In addition, in a preliminary experiment, the applicability and usefulness of the additional determination of salivary estriol was investigated. In conclusion, salivary progesterone may be used as indicator for imminent delivery in pregnant women. Salivary estriol may be an additional parameter that supports the usefulness of salivary progesterone. Further, estriol is said to be a trigger to delivery and is also known to give information about the wellbeing of the fetus. Consequently, its analysis may further contribute to predict the time of delivery, to optionally take measures in the case of premature delivery or complicated pregnancies and give information about the health of the fetus. There is additional research required in order to statistically assess the findings of this study by including more subjects, both having natural deliveries and complicated pregnancies. The results of this study are only intended to indicate the possibility to develop a biosensor for home-use that would greatly contribute to the health of mother and newborn.