The value of serum human placental lactogen and Schwangerschaftsprotein 1 to determine gestation in an ante-natal population.

Single assays of Schwangerschaftsprotein 1 (SP1) and serum human placental lactogen (HPL) were performed in 500 consecutive patients attending a routine ante-natal clinic for their first visit. All samples were taken before 112 days gestation. Of these 500 patients, 233 had a regular menstrual cycle, were certain of last menstrual period (LMP) and delivered a normal infant after spontaneous labour. Regression equations were calculated from these results to assess their value for correcting gestation. Regression equations from previous publications were also applied to our data. The gestation and estimated date of delivery were calculated using SP1 and HPL and were compared with the actual gestation and date of delivery. The correlation was poor and did not indicate that SP1 or HPL could be used to calculate these values in the normal ante-natal population.