A method of determining the stage (gestation) of a pregnancycomprising the steps of quantifying the amount of the hormone hPL or a fragment thereof in a body fluid sample derived from a human female selected from a blood, plasma, serum and/or urine sample, and establishing the stage of pregnancy corresponding thereto. The disclosure also extends to a device adapted to detect the levels/amount of hPL or a fragment thereof in a body fluid sample, derived from a human female, selected from a blood, plasma, serum and/or urine sample, for establishing the stage of pregnancy.