[Intra-uterine insemination: ovarian stimulation or not?]. / Insémination intra-utérine: pourquoi continuer à stimuler l'ovulation?

Conflicting results have been published about intra-uterine insemination efficacy. In many studies, success rates is due to ovarian stimulation and number of follicles. In the present fight against multiple pregnancies, ovarian stimulation is discussed and present pregnancy rates are weak. Our aim is to demonstrate that there is a place for the association controlled ovarian hyperstimulation and intra-uterine insemination in the field of infertility treatments. It is possible to try and recognise women at high risk of multiple pregnancies, keeping the benefit of ovarian stimulation.

[Embryo donation in France, in Europe and in the United States]. / L'accueil d'embryon en France, en Europe et aux Etats-Unis.

Embryo donation, although proposed in a number of ART centres in the world is more often contemplated than performed, and very few publications report results on this subject. There is a great variability in program procedures and policies according to centres in the same country and between countries. In France, this activity is developing slowly. This is due to both the absence of information on the way to organise this activity at the medical level, and to legal constraints imposed by law.

[Prenatal diagnosis of a probable human chimera after fertilization in vitro]. / Diagnostic prénatal d'une probable chimère humaine après fécondation in vitro.

Chimerism is the coexistence of more than one cell line in an individual, due to the fusion of originally separate zygotes. It has been very rarely described in humans. A 36-year-old woman referred for in vitro fertilization (IVF) had three embryos transferred leading to a monofetal pregnancy. Ultrasound examination at 17 weeks showed severe intrauterine growth retardation. Amniocentesis revealed a mixture of 46,XY and 46,XX clones. Histopathologic examination showed a dysmorphic fetus with female phenotype and severe growth retardation. Fusion of two of the three embryos (one male and one female) seems to be the most probable mechanism that could explain both cytogenetic and histopathologic observations.

[Biological assessment criteria during antagonist protocols]. / Critères d'évaluation biologique au cours des protocoles antagonistes.

Until recently, gonadotropin-releasing hormone (GnRH) agonists were the only choice available to physicians for prevention of premature luteinizing hormone (LH) surges in women undergoing controlled ovarian stimulation. The recent approval of GnRH antagonists for this indication gives clinicians some new options. In several trials performed, the GnRH antagonist regimens have been associated with a slightly lower pregnancy and implantation rates than the established GnRH agonist protocols. This review summarizes the main studies concerning oocyte quality and fertilization in IVF cycles with GnRH antagonists. As a result, there is no difference between GnRH agonist and GnRH antagonists concerning oocyte maturation and fertilization rates. There are very few data about the incidence of oocyte morphology anomalies in IVF cycles with antagonists.

Possible human chimera detected prenatally after in vitro fertilization: a case report.

BACKGROUND: Chimerism is the coexistence of more than one cell line in an individual, due to the fusion of originally separate zygotes. It has been very rarely described in humans. METHODS: A 36-year-old woman who was referred for in vitro fertilization (IVF) for unexplained infertility had three embryos transferred. RESULTS: Four weeks and five days after the transfer, ultrasound examination detected a single fetus in the uterus. Ultrasound examination at 17 weeks for metrorrhagia showed severe intrauterine growth retardation. Amniocentesis revealed a mixture of 46,XY and 46,XX clones. Histopathologic examination showed a dysmorphic fetus with female phenotype and severe growth retardation. CONCLUSIONS: Although demonstration by fingerprinting has not been possible, fusion of two of the three transferred embryos (one male and one female) seems to be the most probable mechanism that could explain both cytogenetic and histopathologic observations. No chimera has yet been described after IVF. It would be interesting to collect any such observations from other IVF centers.

Genetic analysis of the oocyte--a review.

Chromosome number abnormalities are remarkably common in human reproduction. Most are caused by chromosomal non-disjunction and premature chromatid separation in oocyte meiosis I. Pooled data from previous studies showed that one in five oocytes that failed to fertilize after in vitro insemination was abnormal when analysed by conventional cytogenetics. Preconception genetic diagnosis, carried out on the first and second polar bodies by FISH, using 5 chromosome-specific probes (13, 16, 18, 21 and 22), showed that the rate of aneuploidy is higher in women aged 35 or over (52.1 per cent). Oocyte dysmorphy seems to have little effect on the rate of aneuploidy except for giant oocytes, which are usually diploid and may cause triploidy after fertilization. Intra- and extrafollicular influences (perifollicular microvasculature, oxygenation, the presence of residues from cigarette smoke) may disturb maturation, leading to immaturity and aneuploidy. Thus, oocyte meiosis is very sensitive to endogenous and exogenous factors that may cause the production of oocytes with chromosomal abnormalities and therefore, of abnormal zygotes.

[Oocyte and embryo quality in polycystic ovary syndrome]. / Qualité des ovocytes et embryons dans le syndrome des ovaires polykystiques.

OBJECTIVE: To compare oocyte and embryo quality in women with Polycystic Ovary Syndrome (PCOS) and in women with normal ovulation. PATIENTS AND METHODS: Forty women with PCOS underwent a total of 67 In Vitro Fertilization (IVF) or Intracytoplasmic Sperm Injection (ICSI) cycles. The control group consisted of women, of the same age, who underwent IVF (for tubal infertility) or ICSI (for male factor infertility) in the same period. RESULTS: The average number of oocytes recovered was higher in the PCOS group (12,1) than in the control group (9.6) as was the rate of immature oocytes (13.8% vs 5.8%; respectively). The fertilization rate was lower in PCOS patients (52% vs 61% in the controls). The cleavage rates, embryo morphology and pregnancy rates were similar in both groups. DISCUSSION AND CONCLUSIONS: Although more oocytes were recovered from PCOS patients, the number of good quality embryos, suitable for transfer or freezing was similar in the two groups as less of the oocytes were mature and the fertilization rate was lower in the PCOS group. IVF or ICSI (according to the indication) are therefore efficient in PCOS patients.

[Consequences of oocyte dysmorphy on the fertilization rate and embryo development after intracytoplasmic sperm injection. A prospective multicenter study]. / Conséquences d'une dysmorphie ovocytaire sur la fécondation et le développement embryonnaire après injection intracytoplasmique, d'un spermatozoïde. Etude prospective, multicentrique.

OBJECTIVES: This prospective study aimed to evaluate the impact of oocyte dysmorphy on the fertilization rate and embryonic development rate in an ICSI programme. PATIENTS AND METHODS: Three hundred and two couples have been included during 302 ICSI cycles, and 1970 oocytes have been studied in 4 ART centres. After decoronisation, 18 morphological criteria, including the size and shape of the oocyte, the thickness of the zona pellucida, the presence or not of debris in the perivitelline space, as well as the appearance of the cytoplasm and polar body have been noted. RESULTS: In total 61.3% of the oocytes presented a dysmorphy, involving, almost equally, the different oocyte compartments. Among the dysmorphic oocytes, half presented more than one anomaly. On average, 9.2% of the oocytes were lysed the day after the micro-injection. The oocytes presenting an enlarged perivitelline space, or multiple vacuoles had a significantly raised lyse rate, 16.3% and 27.8%, respectively. The day after micro-injection, 61.3% of the intact oocytes were fertilized. The rate of fertilization was correlated to the number of abnormalities per oocyte: 1 anomaly: 64.6%, > or = 3 anomalies: 54.6%. The oocytes presenting a large perivitelline space had a slightly lowered fertilization rate (53.4%). On the other hand, those showing a cytoplasm containing refractile bodies had a slightly raised fertilization rate (68.6%). We did not see any statistically significant difference between the different types of oocytes concerning embryonic development at d2. CONCLUSION: These results confirm and contribute new elements with respect to previously published data, showing that (i) oocyte morphology little affects fertilization and the first stages of embryonic development; (ii) certain dysmorphies, (enlargement of the perivitelline space) are specifically deleterious at certain stages in the process (lowering the fertilization rate); (iii) certain morphological differences (the presence of refringent bodies) are not anomalies, but can reflect physiological cellular changes.

Chromosomal abnormalities in oocytes.

Since the beginning of in vitro fertilization (IVF), basic research has provided insight in the field of human reproduction, especially in genetics. Indeed, the contribution of chromosomal abnormalities to oocyte disorders and impaired embryonic development is now well known. Of oocytes that fail to fertilize after in vitro insemination, 26.5% have been found to be abnormal, with 13.3% showing hypohaploidy, 8.1% hyperhaploidy, 1.6% structural abnormalities and 3.5% diploidy. The total incidence of abnormalities seems to be correlated with the fertility status of the woman. It is higher in oocytes from women with tubal or unexplained infertility than in those from women whose husband's infertility is the sole cause of infertility in the couple. Although few oocytes recovered during natural cycles have been studied, gonadotropins, which are widely used to stimulate follicle growth and ovulation, do not increase the risk of abnormalities. The effect of maternal age on fetal aneuploidy, well documented at birth, has not been unambiguously shown to result from an increase in the frequency of aneuploid oocytes. Intra- and extra-follicular influences (perifollicular microvasculature, oxygenation, and the presence of residues from cigarette smoke) may disturb maturation, leading to immaturity and aneuploidy. Thus, oocyte meiosis is very sensitive to endogenous and exogenous factors that could result in oocytes with chromosomal abnormalities and therefore, abnormal zygotes.

ESHRE guidelines for good practice in IVF laboratories. Committee of the Special Interest Group on Embryology of the European Society of Human Reproduction and Embryology.

Education has always been a priority for the European Society of Human Reproduction and Embryology (ESHRE). Many efforts have been dedicated to promoting knowledge of techniques, procedures and strategies in order to ensure use of the highest quality practices in reproductive medicine. The need to develop a set of guidelines was a logical consequence that found its first expression in 1990, when Focus on Reproduction (vol. 1, pp. 10-38) published the first guidelines which were distributed among the membership. Five years later a new, more complete edition with several novel techniques and developments appeared in Human Reproduction (vol. 10, pp. 1246-1271). Both have proved to be invaluable references. Five more years have now passed. The necessity to produce current guidelines for good IVF laboratory practice has provided the strongest motivation. This originated from the increasing awareness that embryologists have a duty to prevent unintentional incidents that might result from poor practice in the laboratory. Therefore, the Embryology Special Interest Group (SIG) undertook to draw up guidelines aimed at giving support and guidance to the laboratory staff. All the aspects required to provide a safe working system were taken into consideration by members of the SIG and their effort produced this document. We hope that it will assist staff in achieving the best clinical outcome for their patients.

Blastocyst stage transfer: the real benefits compared with early embryo transfer.

With the development of commercially available sequential media it is now possible to grow human embryos to the blastocyst stage without feeder cells. The transfer of blastocysts offers several advantages, the most important being synchronization of the embryos with the uterine endometrium and selection of the best quality embryos with a high implantation potential. This study was conducted to compare the efficiency of day 2 and day 5 transfer in a prospective randomized trial involving patients for whom embryo selection was possible (i.e. those with more than three embryos on day 2 following insemination). We obtained equivalent clinical pregnancy rates per cycle for day 2 (41.7%) and day 5 (38.8%) transfer, but fewer embryos were transferred on day 5 (2.24 versus 3.03). The implantation rates were 18.9% on day 2 and 24.1% on day 5. Selected patients with a good response to gonadotrophins (at least eight good quality metaphase II oocytes) may therefore benefit from blastocyst transfer by a reduction in the multiple pregnancy rate, provided no more than two (or even one) blastocyst is transferred.

[Intra-uterine insemination]. / Les inséminations intra-utérines.

Artificial insemination has been proposed for a number of years in the treatment of unexplained or male factors related to infertility with very low results. In recent years, the association of intra-uterine insemination with gonadotropin ovulation induction has demonstrated its effectiveness and it is now the first treatment to propose in these cases before in vitro fertilization.

[In vitro maturation of human oocytes]. / Maturation ovocytaire in vitro dans l'espèce humaine.

Maturation of human oocytes has 3 aspects: nuclear maturation leading to the extrusion of the 1st polar body, membranar maturation essential for the fixation of spermatozoa to the zona pellucida and penetration into the oocyte and cytoplasmic maturation which allows protein synthesis required for normal fertilisation and embryo development. In vitro maturation (IVM) of human oocytes may be appropriate in 5 different situations: for PCOs patients (natural cycle), in normoovulatory patients (natural cycles), for oocytes not exposed to hCG (stimulated cycle), for immature oocytes recovered in the course of an ICSI protocol (stimulated cycle) and after freezing-thawing of immature oocytes. Data from the literature show that in vitro maturation of human oocytes together with ICSI can lead to normal fertilisation, embryo development, pregnancies and the delivery of healthy children. However, the overall efficiency is still very low, indicating that embryo viability is compromised. The incidence of chromosome abnormalities in mature oocytes obtained after IVM is similar to that of oocytes recovered after in vivo maturation and therefore does not seem to be the reason of the failures. Conversely, protein synthesis abnormalities and abnormal calcium signalling might explain the poor viability of the embryos. The key factor seems to be cytoplasmic maturation not yet fully understood in the human.