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STUDIES ON PREGNANCY‐ASSOCIATED PLASMA PROTEIN A IN THE THIRD TRIMESTER OF PREGNANCY
Author(s) -
Smith R.,
Bischof P.,
Hughes G.,
Klopper A.
Publication year - 1979
Publication title -
bjog: an international journal of obstetrics and gynaecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.157
H-Index - 164
eISSN - 1471-0528
pISSN - 1470-0328
DOI - 10.1111/j.1471-0528.1979.tb10716.x
Subject(s) - syncytiotrophoblast , intervillous space , pregnancy , placenta , blood proteins , pregnancy associated plasma protein a , obstetrics , medicine , fetus , andrology , endocrinology , biology , first trimester , genetics
Summary The plasma concentration of pregnancy‐associated plasma protein A (PAPP‐A) was measured in 34 women during the last 10 weeks of pregnancy. From 30 to 36 weeks the concentration of this protein increased steadily. Thereafter the concentration of PAPP‐A rose more steeply, the highest amounts being found in early labour. The concentration of PAPP‐A in peripheral venous blood and in the uterine vein was much the same. It was less in the retroplacental blood and a great deal less in the peritoneal fluid. The day‐to‐day variation was small; the coefficient of variation at 38 weeks was only 7.3 per cent. After delivery, the concentration of PAPP‐A fell more slowly than other placental proteins and steroids, the average half‐life being 51 hours. Although there is no doubt that PAPP‐A is a product of the syncytiotrophoblast, our findings suggest that it is not simply secreted by the chorionic villi directly into the intervillous space but makes its way into the maternal circulation by a more circuitous route.