Maternal serum human chorionic gonadotrophin and pregnancy-associated plasma protein A in twin pregnancies in the first trimester

Abstract

Twin pregnancies secrete more PAPP-A than expected on the basis of singleton controls whereas free beta-hCG production is not increased. The results of the present study can be used to establish normal reference values when introducing first trimester Down syndrome screening in prenatal care.

Distributions of current and new first‐trimester Down syndrome screening markers in twin pregnancies

“…In this study distributions of four first-trimester biochemical markers were established for monochorionic and dichorionic twin pregnancies. The median MoMs of PAPP-A and fβ-hCG were approximately twice as high as compared to singleton pregnancies and were comparable to medians found in previous studies (Spencer, 2000;Niemimaa et al, 2002;Spencer and Nicolaides, 2003;Mashiach et al, 2004;Goncé et al, 2005;Spencer et al, 2008a;Linskens et al, 2009). The median PAPP-A MoMs in the current study tended to increase during the first trimester.…”

“…screening markers between monochorionic and dichorionic twin pregnancies (Niemimaa et al, 2002;Goncé et al, 2005;Spencer et al, 2008a;Linskens et al, 2009). Recently, Spencer et al-and Linskens et al in a smaller study-reported a significantly lower PAPP-A MoM in monochorionic compared to dichorionic twin pregnancies.…”

“…To distinguish between the two, ultrasound examination can be used (Sepulveda et al, 1996;Vayssièrre et al, 1996). Despite many studies on the risk estimation for Down syndrome in twin pregnancies it remains unclear whether and to what extent there is a significant difference in biochemical parameter concentrations between monochorionic and dichorionic twins (Spencer, 2001;Niemimaa et al, 2002;Muller et al, 2003;Goncé et al, 2005;WØjdemann et al, 2006;Spencer et al, 2008a;Linskens et al, 2009). Previous studies of first-trimester serum screening concentrated mainly on determining normal values for PAPP-A and fβ-hCG in twin pregnancies (Spencer, 2000;Niemimaa et al, 2002;Spencer and Nicolaides, 2003;Mashiach et al, 2004).…”

“…Despite many studies on the risk estimation for Down syndrome in twin pregnancies it remains unclear whether and to what extent there is a significant difference in biochemical parameter concentrations between monochorionic and dichorionic twins (Spencer, 2001;Niemimaa et al, 2002;Muller et al, 2003;Goncé et al, 2005;WØjdemann et al, 2006;Spencer et al, 2008a;Linskens et al, 2009). Previous studies of first-trimester serum screening concentrated mainly on determining normal values for PAPP-A and fβ-hCG in twin pregnancies (Spencer, 2000;Niemimaa et al, 2002;Spencer and Nicolaides, 2003;Mashiach et al, 2004). Recently, several new screening markers have been tested and their potential improvement concerning Down syndrome screening has been investigated (Laigaard et al, 2006;Spencer et al, 2008b;Koster et al, 2009;Wortelboer et al, 2009).…”

Early first‐trimester free‐β‐hCG and PAPP‐A serum distributions in monochorionic and dichorionic twins

“…Previous studies have concentrated on setting reference values for free-β-hCG and PAPP-A in unaffected twins. 4,5,7,8 Lately, studies have been focused on possible differences in biochemical markers distribution between monochorionic and dichorionic twins. [10][11][12] Koster et al 11 concluded there were no significant differences in biochemical parameters despite chorionicity.…”