PREGNANCY SPECIFIC β₁ GLYCOPROTEIN AND CHORIONIC GONADOTROPHIN IN EARLY HUMAN PREGNANCY

Abstract

Venous blood samples were collected prospectively in ten menstrual cycles where conception occurred, and for several weeks thereafter, and the circulating concentrations of pregnancy specific beta 1 glycoprotein (SP1) and human chorionic gonadotrophin (HCG) determined using specific radioimmunoassays. The data were converted to logarithms and pooled and pooled using the day of the LH peak as zero time. The concentration profiles so obtained were remarkable similar and showed a rapid exponential increase in concentration during the very early stage of pregnancy. The doubling times were 2.4 days and 2.3 days for SP1 and HCG respectively and both proteins were initially secreted in approximately equivalent concentrations. However, some 30 days following the LH peak, the concentration profiles began to diverge, with SP1 levels continuing to rise whilst HCG concentrations showed the characteristic plateau at 8 and 10 weeks of gestation.

Schwangerschaftsprotein 1 (Sp1) as a Maternal Serum Marker for Down Syndrome in the First and Second Trimesters

“…The values found for MSSP1 in normal controls correspond well to values reported by others (Lenton et al, 1981;Sørensen et al, 1995) and the distribution as a function of the gestational age, with an early very steep rise followed by what could be considered an exponential rise with decreasing slope, has previously been suggested as a model for the development of MSSP1 over gestational age (Sørensen et al, 1995). This finding, together with the good operational characteristics of the TrIFMA as described in this study, makes the TrIFMA suitable for inclusion in large volume screening programmes, particularly so, as a system for automation and simultaneous determination of other parameters by timeresolved immunofluorescence is commercially available (Wallac OY, Turku, Finland).…”

“…The concentration of SP1 in maternal serum (MSSP1) increases throughout pregnancy (Schultz-Larsen and Herz, 1978;Lenton et al, 1981) and it is a prognostic indicator in pregnancy complications (Brambati et al, 1991;Johnson et al, 1993). In Down syndrome (DS) pregnancies, elevated MSSP1 in the second trimes-ter has been described (Bartels and Lindemann, 1988;Wald et al, 1989;Knight et al, 1989;Bartels et al, 1990Bartels et al, , 1994Petrocik et al, 1990;Graham et al, 1992).…”

Serum chorionic gonadotrophin (hCG), schwangerschaftsprotein 1(SP1), progesterone and oestradiol levels in patients with nausea and vomiting in early pregnancy

“…Circulating levels of S P 1 have not been studied previously in relation to nausea and vomiting i n pregnancy. As with hCG there is a rapid output of SPl in the first trimester (Lenton et al 1981) and it was therefore considered a possible causal agent of nausea and vomiting ill early pregnancy. No significant differences in SP1 levels were noted.…”

Clinical Value of Pregnancy‐Specific β1‐Glycoprotein (SP1) and β‐hCG Determination in Serum in Suspected Ectopic Pregnancy

“…Both the enzyme-immunoassay for SP determination and the radio-immunoassay for (3- It is uncertain whether measurement of SPl is superior to measurement of serum P-hCG, which has been used hitherto. First, both SP, and 0-hCG have a doubling time of 2 -3 days and both have a plasma concentration of 1 pg/l within 9 -11 days of the LH peak (16), which corresponds to about 2 -5 days after implantation. Secondly, in a few serum samples of ectopic pregnancies, only one of the proteins, P-hCG or SP,, was present in an appreciable concentration (7).…”