THANOS PARASHOS obstétricien-gynécologue.

Dr Thanos Paraschos est un obstétricien et gynécologue de renommée internationale, spécialisé dans l'infertilité et la fécondation in vitro. Il a eu le privilège d'effectuer le premier diagnostic préimplantatoire génétique dans le monde (1989 ), avec le Professeur Robert Lord Winston et A.H. Handyside à l'Hôpital Hammersmith de Londres, lequel est le chef de file mondial dans la recherche et le traitement des problèmes d'infertilité.
Il est le directeur médical de ``EmBIO``, unité de fécondation in vitro, à Athènes, en Grèce, qu'il a fondé en 1996.
En travaillant dans l'équipe de Robert Winston, Thanos Paraschos a inventé le Cathéter rigide Wallace, utilisé depuis par des milliers de scientifiques du monde entier pour des transferts d'embryons particulièrement exigeants.
Son implication approfondie dans la recherche médicale sur la fécondité et les technologies de procréation assistée comprend de publications médicales importantes, parues dans des revues spécialisées médicales.

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Expérience professionnelle

Poste actuel

Obstétricien - Gynécologue, Directeur du Centre Médical Embio

Anciens postes

Mars 1995 - Mars 1996
MEDECIN-SPECIALISTE Α' Hôpital Whipps Cross, Londres	Département de gynécologie avec Linsday Mc Millan Interventions en chirurgie laparoscopique de pointe
Mars 1993 - Mars 1995
MEDECIN-SPECIALISTE Α' /CHERCHEUR Hôpital Hammersmith	Institut d’obstétrique et de gynécologie. Ecole royale de formation médicale avec le Professeur Lord Robert Winston Département de Gynécologie et d'une FIV
Mars 1992 - Mars 1993
GREFFIER Southmead Hospital	Bristol, Angleterre Auprès deMr D N Joyce, Mr Phillip SmithetMlle G Turner "Obstétrique et gynécologie"
Novembre 1991 - Février 1992
Senior House OFFICER	Auprès deMr D.N. Joyce et de Mr D. McCoy Southmead Hospital, Bristol, Angleterre "Gynécologie"
Février 1991 - Juillet 1991
Senior House OFFICER	Auprès deMlle G Turner et Mr Phillip Smith Southmead Hospital, Bristol, Angleterre "Obstétrique"
Août 1990 - Janvier 1991
Interne principal	Auprès duDr B D Speidel & du Professeur Neil Marlow Southmead Hospital, Bristol, Angleterre "Pédiatrie néonatale" (Expérience facultative)
Février 1990 - Juillet 1990
Interne principal	Auprès deMr Rick Warren et Mr Crocker Norfolk and Norwich Hospital, Norwich Norfolk, Angleterre "Gynécologie"
Août 1989 - Janvier 1990
Senior House OFFICER	Auprès deMr Simon Crocker, Mr Rick Warren et Mr Roger Martin Norfolk and Norwich Hospital Norwich Norfolk, Angleterre "Obstétrique"
Août 1988 - Juillet 1989
Interne principal	Auprès duLord Robert Winston et Mr Raul Margara Hammersmith Hospital Institut d'obstétrique et de gynécologie Royal Postgraduate Medical School "Etudes de la régulation de la fécondité et de la stérilité"

Abstracts of some publications in peer review journals

J Assist Reprod Genet. 1996 Mar;13(3):254-8.

Pregnancies resulting from embryos biopsied for preimplantation diagnosis of genetic disease: biochemical and ultrasonic studies in the first trimester of pregnancy.

Soussis I, Harper JC, Kontogianni E, Paraschos T, Packham D, Handyside AH, Winston RM.

Institute of Obstetrics & Gynaecology, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.

PURPOSE: Our purpose was to investigate early biochemical and ultrasonic measurements of pregnancies resulting from embryos biopsied for preimplantation diagnosis of inherited disease. RESULTS: Singleton pregnancies following biopsy had lower initial hCG levels [10 or 12 days after oocyte recovery (OR)], which rose steeply to match the controls by 16 days after OR. Twin biopsied pregnancies showed hCG levels lower than those of twin control pregnancies, which rose in parallel with the controls but remained lower for a longer period than the singletons. Progesterone levels showed a wide variation. Ultrasound measurements showed that overall the mean sac diameter and crown-rump length at 28 and 42 days after egg collection were similar in biopsied and control pregnancies. CONCLUSIONS: Pregnancies resulting from biopsied embryos behave similarly to control IVF pregnancies. However, the reduction in cell mass following embryo biopsy occasionally results in reduced levels of circulating serum hCG and smaller ultrasound measurements in early pregnancy.

1: Prenat Diagn. 1996 Feb;16(2):137-42.

Clinical experience with preimplantation genetic diagnosis of cystic fibrosis (delta F508).

Ao A, Ray P, Harper J, Lesko J, Paraschos T, Atkinson G, Soussis I, Taylor D, Handyside A, Hughes M, Winston RM.

Institute of Obstetrics and Gynaecology, RPMS, Hammersmith Hospital, London, UK.

Preimplantation genetic diagnosis (PGD) was attempted in 12 couples in whom both parents carry the common delta F508 deletion causing cystic fibrosis (CF). In vitro fertilization (IVF) was followed by cleavage stage biopsy on days 2 and 3 and removal of one or two cells for genetic analysis by nested polymerase chain reaction (PCR) and heteroduplex formation. A total of 18 cycles resulted in 137 normally fertilized embryos, of which 115 developed to cleavage stages and 114 were successfully biopsied. Genetic analysis was successful in 83 embryos (73 per cent). With the remaining embryos, either results from two or more cells were discordant or amplification failed. In 15 cycles, one or two either normal or carrier embryos were transferred and five (33 per cent) clinical pregnancies were established. Five singletons have been born and at birth all five babies have been confirmed as homozygous for the normal allele. Our experience demonstrates that IVF and cleavage stage biopsy consistently provides sufficient embryos, diagnosed as unaffected, for transfer in this autosomal recessive disease and that pregnancy rates are comparable to those following IVF.

1: Hum Reprod. 1995 Jun;10(6):1507-11.

Results of IVF in patients with endometriosis: the severity of the disease does not affect outcome, or the incidence of miscarriage.

Geber S, Paraschos T, Atkinson G, Margara R, Winston RM.

Hammersmith Hospital, Institute of Obstetrics and Gynaecology, Royal Postgraduate Medical School, London, UK.

The literature suggests that the results of in-vitro fertilization (IVF) for patients with endometriosis depend on the stage of the disease, and that patients with severe endometriosis have a higher failure rate. Miscarriage is said to be more prevalent in women treated for endometriosis. In the study reported here, 140 patients with endometriosis underwent 182 cycles of IVF using gonadotrophin-releasing hormone analogues (GnRHa). Patients with endometriosis only were allocated to one group (group 4). The results were compared with those of three other groups of patients undergoing the same treatment within the same period. Group 1 consisted of couples with male factor only (45 cycles), group 2, couples with unexplained infertility (196 cycles) and group 3, couples with a tubal factor only (1139 cycles). The mean age of the patients, mean number of human menopausal gonadotrophin (HMG) ampoules administered, oestradiol concentration on the day of human chorionic gonadotrophin administration, number of days of HMG, mean number of oocytes retrieved and retrieval rate were not significantly different. The fertilization rate was significantly lower in group 1; no difference was observed in the other three groups. The mean number of normally fertilized embryos was not significantly different. The number of transferred embryos in each cycle and the implantation rates were similar in the four groups. The overall pregnancy rate per transfer was 39% in group 1, 48% in group 2, 45% in group 3 and 40% in group 4.(ABSTRACT TRUNCATED AT 250 WORDS)

1: Hum Reprod. 1994 Nov;9(11):2135-8.

The zona reaction in human oocytes as seen with scanning electron microscopy.

Nikas G, Paraschos T, Psychoyos A, Handyside AH.

Laboratoire de Physiologie de la Reproduction, Hôpital Bicêtre, Bâtiment Gregory Pincus, INSERM, Le Kremlin-Bicêtre, France.

Using scanning electron microscopy we found differences in the fine structure of the zona pellucida between unfertilized and fertilized human pronuclear stage oocytes in an in-vitro fertilization programme. In unfertilized oocytes, the zona pellucida appeared porous, comprising a large number of ring-shaped structures, called hoops, randomly superimposed in several layers. Superficial pores had a mean diameter of 4 microns, with the diameter decreasing in more inner lying pores. In fertilized oocytes, the zona pellucida was compact; the hoops appeared to melt and the pores to be obliterated by an amorphous material emerging from the inner zona. The micrographs provide ultrastructural evidence of the zona reaction in human oocytes and give insights into the morphological and mechanical aspects of the polyspermy-blocking mechanism in humans.

1: Hum Reprod. 1995 Aug;10(8):2125-35.

Normal development and metabolic activity of preimplantation embryos in vitro from patients with polycystic ovaries.

Hardy K, Robinson FM, Paraschos T, Wicks R, Franks S, Winston RM.

Human Embryology Laboratory, Royal Postgraduate Medical School, Hammersmith Hospital, London, UK.

Polycystic ovary syndrome (PCOS) is closely associated with high miscarriage rates and, following in-vitro fertilization (IVF), with decreased fertilization rates, suggesting that oocytes and embryos are of poor quality. In this prospective study, we examined the development, metabolic activity and blastocyst cell number of embryos following IVF from 51 patients with either anovulatory PCOS, ovulatory PCOS or tubal disease. The number of oocytes retrieved and the fertilization rates were similar for patients with PCOS and tubal disease. Following embryo transfer, 46% of the patients with PCOS and 36% of patients with tubal disease became pregnant. A similar proportion of surplus embryos from patients with PCOS and tubal disease developed to the blastocyst stage (38% and 43% respectively). Patients with anovulatory PCOS had embryos with less fragmentation which cleaved faster, cavitated earlier and had more cells at the blastocyst stage than embryos from patients with tubal disease. While the profile of glucose uptake and lactate production was similar for all groups throughout preimplantation development, patients with tubal disease who underwent ovulation induction using the 'titrated' regimen optimized for PCOS patients resulted in embryos with reduced pyruvate uptake, in addition to low blastocyst cell numbers. This study demonstrates that with an optimized ovulation induction regimen, embryos from PCOS patients are of good quality and developmental potential.

1: Br J Obstet Gynaecol. 1995 Jun;102(6):471-4. Links

Endovaginal ultrasonography in the diagnosis of adenomyosis uteri: identifying the predictive characteristics.

Brosens JJ, de Souza NM, Barker FG, Paraschos T, Winston RM.

Department of Obstetrics and Gynaecology, Hammersmith Hospital, London, UK.

OBJECTIVE: To evaluate prospectively the role of endovaginal ultrasonography in the diagnosis of adenomyosis and to identify predictive characteristics. SETTING: In Vitro Fertilisation Unit, Hammersmith Hospital. SUBJECTS: Fifty-six women with menorrhagia and dysmenorrhea. DESIGN: Endovaginal sonography was performed and uterine body morphometry and myometrial echogenicity were assessed. The sonographic suspicion of adenomyosis was scored high or low depending on the degree of uterine enlargement, uterine asymmetry not due to fibroids and heterogenicity of myometrial echoes.