Pregnancies conceived using assisted reproductive technologies (ART) have low levels of pregnancy-associated plasma protein-A (PAPP-A) leading to a high rate of false-positive results in first trimester screening for Down syndrome
Authors: Amor, D.J.; Xu, J.X.; Halliday, J.L.; Francis, I.; Healy, D.L.; Breheny, S.; Baker, H.W.G.; Jaques, A.M.
Source: Human Reproduction, Volume 24, Number 6, 3 June 2009 , pp. 1330-1338(9)
Publisher: Oxford University Press
First trimester screening (FTS) for Down syndrome combines measurement of nuchal translucency, free beta-human chorionic gonadotrophin and pregnancy-associated plasma protein-A (PAPP-A). The aim of this study was to undertake a detailed analysis of FTS results in singleton pregnancies conceived using assisted reproductive technologies (ART) and non-ART pregnancies.
A record linkage study compared outcomes in 1739 ART-conceived and 50 253 naturally conceived pregnancies.
Overall, significantly lower PAPP-A levels were detected in ART pregnancies (0.83 multiples of median, MoM) than in controls (1.00 MoM) (t-test P < 0.001). This difference remained after excluding complicated pregnancies. Analysis of factors affecting PAPP-A levels suggested fresh compared with frozen embryo transfers and use of artificial cycles compared with natural cycles for frozen transfers were associated with lower values. The adjusted odds ratio (AdjOR) for receiving a false-positive result was 1.71 (95 CI 1.442.04; P < 0.001) for ART pregnancies compared with non-ART pregnancies, and this leads to a higher AdjOR (1.24, 95 CI 1.031.49; P 0.02) for having a chorionic villous sampling (CVS) or amniocentesis.
ART pregnancies have reduced FTS PAPP-A levels leading to an increased likelihood of receiving a false-positive result and having a CVS/amniocentesis. Lower PAPP-A may reflect impairment of early implantation with some forms of ART.
Document Type: Research Article
Publication date: 2009-06-03
- Human Reproduction features full-length, peer-reviewed papers reporting original research, clinical case histories, as well as opinions and debates on topical issues. Papers published cover the scientific and medical aspects of reproductive physiology and pathology, endocrinology, andrology, gonad function, gametogenesis, fertilization, embryo development, implantation, pregnancy, genetics, genetic diagnosis, oncology, infectious disease, surgery, contraception, infertility treatment, psychology, ethics and social issues. The highest scientific and editorial standard is maintained throughout the journal along with a rapid rate of publication.