Dr Francois Vialard
Dr François Vialard graduated in Pharmacy in 2000 and received his MD in 2006. He is the Co-Director of the Cytogenetic Laboratory in the Poissy Saint Germain Hospital since December 2000. At the hospital, Dr Vialard performs prenatal cytogenetic diagnosis, postnatal cytogenetic diagnosis, pre-conceptional diagnosis on 1st polar body, spermFISH and CGHarray.
Dr François Vialard coordinates scientific programs on Epigenetic and Infertility, CGH array, Chromosome rearrangement and infertility, Predisposition to infertility, Prenatal diagnosis and Assisted Reproduction Technology.
Dr François Vialard is the treasurer of the French Cytogenetic Society as well as a member of the Preimplantation Genetics Diagnosis International Society and the SALF (French Society of Andrology) and the French Genetics Society
Project: PIF- BIOMARKER OF SUCCESSFUL PREGNANCY
Pregnancy viability/failure depends on embryo viability, implantation and proper placentation.Our multicenter study evaluates PIF’s (PIF* proprietary technology) utility in the prediction of normal and abnormal pregnancies. The study includes four core Reproductive/Maternal Foetal Medicine Centers. Preimplantation factor (PIF*) is a 15aa embryo-derived peptide, produced early (2cell stage) and throughout viable pregnancy. PIF’s key functions are immunomodulation, inflammation and engraftment control (PIF i.e. modulates maternal immunity, promotes adhesion, endometrial remodelling and trophoblast invasion).
1- PIF: biomarker of successful implantation
To overcome the poor reproductive potential of embryos generated during in vitro fertilization cycles and the lack of markers enabling the identification of the most competent ones, it is common to transfer multiple embryos. However, this practice is associated with the risks of multi-foetal pregnancies and high morbidity/mortality. Ideally, the availability of a marker specifically produced by viable embryos would permit the transfer of a single embryo (SET) without affecting the chances of pregnancy and, most importantly, capable to drastically reduce multiple pregnancies after IVF. In preliminary work, we demonstrated that no pregnancy resulted following the transfer of embryos where PIF was undetectable in culture media. Further PIF presence led to 42% clinical pregnancy rate following SET. Using a bead-based competitive immunoassay (Luminex system), we will correlate PIF levels in embryo culture media with implantation rates following SET.
2- PIF: biomarker of pregnancy, miscarriage, premature birth, preeclampsia, placenta accreta.
Except for serum hCG, no pregnancy-complication markers are widely employed to predict the need for medical intervention. Since circulating PIF is present throughout viable pregnancy, it may represent a specific candidate biomarker. PIF levels will be analyzed in serum of pregnant women in a range of settings: a) following IVF; b) index pregnancy of women with history of recurrent pregnancy loss, c) index pregnancy of women with history of placenta mediated complications such as: intrauterine growth restriction, spontaneous idiopathic preterm delivery, and preeclampsia; and d) index pregnancy in women with evidence of abnormal placentation, namely placenta accreta and related conditions. For pregnancy complications, PIF expression will also be analyzed by immunochemistry in the placenta and at the uteroplacental interface.
3- In vitro PIF studies to explore its role in human implantation and placentation.
Since PIF promotes human trophoblastic cell line invasion, we will perform complementary in vitro studies on human primary trophoblast from first trimester placenta. Moreover, to define the precise the role of PIF on implantation and placentation processes, we will be using a global approach, examining PIF effects on trophoblast proliferation, and analyte secretion by genome-wide expression and comprehensive proteomic analysis.
