Maternal blood concentrations of the two forms of pregnancy specific B1 glycoprotein [SP1 beta and SP1 alpha] in the first half of normal pregnancy: reference values

For the first time, the concentrations of the two components of pregnancy specific beta 1 glycoprotein [SP 1 beta and SP 1 alpha] were estimated in 531 blood samples from 93 normal pregnancies during 4 to 20 weeks of gestation. The level of each protein was detected as early as the fourth week of pregnancy and rose progressively onwards. The normal range was calculated using the mean and standard deviation as well as logarithmic transformation of the values. Serial determinations for the same individuals showed very little divergence from the average curve. The diurnal variations for each protein also showed no significant difference. SP 1 beta and SP 1 alpha assays in the maternal blood seem to fulfill the criteria of an index for monitoring of the fetoplacental function. Serial determinations for the same pregnant women expected to give a rather more precise information than single estimation