[Analysis of prenatal follow-up strategies for trisomy 21 affected pregnancies in France]

OBJECTIVE

The main objective of this study was to screen the prenatal follow-up of women with live birth trisomy 21 child in order to evaluate the proportion of prenatal screening failure versus cases where the women refused either the screening or the prenatal diagnosis of Down syndrome. This study covers the period of time from 2009 to 2012 when the national prenatal screening policy changed from second to first trimester and allows for a comparative assessment of the nationwide efficiency of the various maternal serum marker based strategies.

METHOD

All authorized cytogenetic laboratories sent required data for all cases of trisomy 21 diagnosed in FRANCE in new-borns (less than 1-year-old) from January 2010 to July 2013.

RESULTS

A total of 1253 cases of trisomy 21 were diagnosed before 1 year of age whose mother did not had prenatal diagnosis. For 861 of them, information on the prenatal follow-up was available, with 72% of cases where a prenatal screening was organized either by maternal serum marker or by ultrasound. Results of the screening strategy was positive with maternal serum marker in 28% of cases (calculated risk≥1/250), positive because of abnormal ultrasound in 5% and negative with maternal marker screening (whatever the strategy used) in 67% of cases. Detection rate over the period of the study was 82%, with similar efficiency of first and second trimester strategies (83%) but significantly lower with sequential association of first trimester Nuchal translucency measurement and second trimester serum screening (70%).

CONCLUSION

Switching from second trimester to first trimester screening strategy, with as many trisomy 21 foetuses diagnosed with half invasive procedures fulfilled national health policy objectives. Analysis of these data gives useful insights to elaborate a future screening policy involving cell-free foetal DNA sequencing.

Decline in semen concentration and morphology in a sample of 26,609 men close to general population between 1989 and 2005 in France

STUDY QUESTION

Are temporal trends and values of semen quality parameters in France identifiable in partners of totally infertile women?

SUMMARY ANSWER

Among a sample of 26 609 partners of totally infertile women undergoing an assisted reproductive technology (ART) procedures in the whole of France over a 17-year period, there was a continuous decrease in semen concentration of about 1.9% per year and a significant decrease in the percentage with morphologically normal forms but no global trend for motility.

WHAT IS KNOWN ALREADY

A global decrease in human sperm quality is still debated as geographical differences have been shown, and many criticisms have risen concerning studies with small and biased study populations or inappropriate statistical methodology. However, growing biological, toxicological, experimental and human exposure data support the endocrine disruptors' hypothesis assuming that fetal exposure to endocrine disruptors could impair reproductive outcomes.

STUDY DESIGN, SIZE, DURATION

This was a retrospective and descriptive study using data registered by Fivnat, the professional association in charge of statistics for ART in France during the 1989-2005 study period. Data were provided by 126 main ART centres over the whole metropolitan territory. The source population included 154 712 men, aged 18-70, who were partners of couples undergoing their first ART cycle and for whom semen quality indicators (concentration, total motility and percentage of morphologically normal forms), measured on fresh ejaculated semen, were available.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study population was 26 609 partners of women who had both tubes either absent or blocked. The temporal trends for each indicator of semen quality were modelled using a generalized additive model that allowed for nonlinear relationships between variables and were adjusted for season and age. In-depth sensitivity analyses included the reiteration of the analysis on data from a second spermiogram available for each man and on another subsample of men diagnosed as fertile. Variables such as centre, technique (standard in vitro fertilization or intra-cytoplasmic sperm injection) and an interaction factor between technique and time were also included in the model.

MAIN RESULTS AND THE ROLE OF CHANCE

There was a significant and continuous decrease in sperm concentration of 32.2% [26.3-36.3] during the study period. Projections indicate that concentration for a 35-year-old man went from an average of 73.6 million/ml [69.0-78.4] in 1989 to 49.9 million/ml [43.5-54.7] in 2005. A significant, but not quantifiable, decrease in the percentage of sperm with morphologically normal forms along the 17-year period was also observed. There was no global trend but a slight, significant increase in total motility between 1994 and 1998 was observed. The results were robust after sensitivity analysis.

LIMITATIONS, REASONS FOR CAUTION

Socioeconomic status could not be controlled for. Despite universal access to medical services in France, couples undergoing ART are expected to have a higher educational level on average compared with those of the general population. Therefore, the real values in the general population could be slightly lower than those presented and the decrease possibly stronger, as the population study is less likely to smoke or be overweight, two factors known to impair semen quality.

WIDER IMPLICATIONS OF THE FINDINGS

As the men were selected without a priori knowledge regarding their semen quality characteristics, the results are expected to be close to the values in the general French population. The very large sample size and the robustness of the results confer great statistical power and credibility to the results. To our knowledge, it is the first study concluding a severe and general decrease in sperm concentration and morphology at the scale of a whole country over a substantial period. This constitutes a serious public health warning. The link with the environment particularly needs to be determined.

Semen variation in a population of fertile donors: evaluation in a French centre over a 34-year period

Although it has been suspected that there is a decrease in semen quality over time, the results reported to date remain debatable because of methodological issues. The aim of the study reported here was to investigate the evolution of semen quality over time in a population of 1114 fertile candidates for sperm donation at CECOS, Tours, between 1976 and 2009. We investigated semen volume, sperm concentration, progressive motility, vitality, percentage of normal forms and multiple abnormalities index of the first ejaculate in this population. We did not find a decline in semen volume, whereas we observed a significant decrease in total sperm count (from 443.2 million in 1976 to 300.2 million in 2009), motility (from 64% in 1976 to 49% in 2009) and vitality (from 88% to 80%). Moreover, a significant decline in the percentage of normal forms was noted between 1976 and 1997 (from 67% to 26%) with a steady rise in the multiple abnormalities index between 1998 and 2009 (from 1.19 to 1.65). This study involving a population of fertile men from a restricted area revealed various degrees of decline in semen parameters over a period of 34 years. These findings will have to be compared with findings in other geographical areas.

Sperm morphology assessment using David's classification: time to switch to strict criteria? Prospective comparative analysis in a selected IVF population

The aim of this study was to compare assessment of sperm morphology by using David's classification (DC), a method of manual analysis most common in France, with a computer-assisted method (Integrated Visual Optical System) based on the strict criteria (CASA SC) for their ability to predict fertilization in a selected in vitro fertilization (IVF) population. A total of 120 couples engaged in IVF protocols were prospectively included in the study. To focus mainly on sperm morphology, couples were excluded in cases of abnormalities of sperm concentration and/or motility and immunological factors and when a low number of oocytes were collected. Sperm morphology analysis was performed on the day of oocyte retrieval by the same trained biologist. Our results showed a moderate correlation between the two techniques (r = 0.49). The DC sperm morphology analysis was less indicative of fertilization than CASA SC (r = 0.07, p = 0.47 vs. r = 0.22, p = 0.014). Using receiver-operating characteristics analysis, we showed that DC was not discriminating in the prediction of fertilization (AUC = 0.572). DC seemed less appropriate for the prediction of fertilization success or failure. In contrast, with CASA SC, the previously determined cut-off value of around 14% was confirmed (AUC = 0.735, cut-off = 6%). Our results argue in favour of the replacement of DC by SC to tend towards worldwide standardization.

[Semen characteristics and quality of the conceptus in fertilization in vitro]

OBJECTIVE

Assisted reproductive technology (ART) is associated with increased risks for the neonate, compared to natural fertility, mainly because of multiple pregnancies and increased maternal age. On the opposite, the impact of paternal factors has been scarcely studied, except for the relationship between surgically retrieved sperms and genetic abnormalities.

PATIENTS AND METHODS

This study has been realized using the large French register on in vitro fertilization (FIVNAT) that collects information on 80% of French ART activity. For the study, all the pregnancies obtained from oocyte recoveries between January 1996 and December 2003, for which information on cycles could be linked to the pregnancy were included, i.e. 34223 pregnancies, resulting in 27025 deliveries and 33945 neonates. Sperm quality was defined either according to the semen origin (spouse's ejaculate, epididymis, testis, or donor), or according to the spermiogramme values for concentration, motility and morphology. The statistical analysis included the use of multivariate logistic models, with the main prognostic factors.

RESULTS

The delivery, spontaneous abortion and ectopic pregnancy rates were not influenced by semen origin nor by quality, all the 95% confidence intervals including 1. The neonates conceived through surgically retrieved sperms were at a slightly increased risk of hypotrophy (weight under the 10% centile of reference curves) and of malformation (OR=1.18, 95CI: 1.03-1.36 and OR=1.30 [0,95-1,84], respectively). On the opposite, when analysis was restrained to ejaculated semen, no risk was demonstrated.

DISCUSSION AND CONCLUSION

The semen quality has little impact on pregnancy issue. Only the semen origin seems to act on hypotrophy and malformation, but these results deserve to be further analyzed for confirmation.

Meiotic segregation in spermatozoa of a 45,XY,-14,der(18)t(14;18)(q11;p11.3) translocation carrier: a case report

A 35-year-old male was found to have a 45,XY,-14,der(18)t(14;18)(q11;p11.3) karyotype during the investigations for a couple with infertility for 8 years. Two sperm samples were obtained and analysed in triple fluorescence in situ hybridization (FISH) with the D18Z1 and LSI IGH/BCL2 probes. The frequency of gametes exhibiting a normal or balanced chromosomal equipment was 87.26 and 90.97% in samples 1 and 2, respectively. No statistically significant difference was found between the results of meiotic segregation of both samples. These proportions are close to those observed among Robertsonian translocation carriers. They can probably be explained by the formation of trivalent in cis configuration during meiosis I between the derivative chromosome and the normal chromosomes 14 and 18, as in Robertsonian translocation carriers. These results suggest that the configuration adopted at pachytene strongly determines the segregation mode that will be preferentially followed during anaphase I.

[Sequential assessment of individually cultured embryos in IVF]

OBJECTIVE

It is a challenge for IVF centers to propose a method to select the most viable embryo to transfer, thereby minimizing the risk of multiple births. In this study, a prospective investigation was made to determine if non-invasive developmental markers on day 1 combined to conventional evaluation on day 2 can predict in vitro blastocyst development.

PATIENTS AND METHODS

A total of 4190 individually cultured embryos from patients undergoing IVF/ICSI treatment at the Tours University Hospital Center from January 2002 to December 2004 were included. Individual embryos were cultured in sequential media in microdrops under mineral oil from j1 to j5/j6 allowing to record their sequential growth until the blastocyst stage.

RESULTS

The results showed a significant positive relationship between pattern 0 zygote, early cleavage, 4 cells embryos with < 20% fragmentation on day 2 and the rate of blastocyst development on day 5 (P < 0.05). In our hands, zygote pattern does not bring additional benefit to better select embryo.

DISCUSSION AND CONCLUSION

Zygote and early cleavage assessments on day 1, morphological appearance on day 2 are some other parameters related individually to blastocyst development on days 5 and 6. These parameters can be used collectively to establish a predictive in vitro sequential embryo assessment model for routine use in IVF clinics.

Le dialogue ovocyte–cumulus

The dialog between oocyte and cumulus cells brings a major contribution for oocyte meiotic and developmental competence. On the one hand, the oocyte will modulate follicle growth through specific gene expression (Figalpha, GDF-9, BMP15) as well as its meiosis (GPR3 et PDE3A). Beyond its action on proliferation, oocyte will control in part the differentiation of cumulus cells with a particular involvement of GDF-9, BMP15 in this late maturation process. On the other hand, somatic cells are the main targets of gonadotropins and will modulate both oocyte growth and maturation. Gap-junctions between oocyte and cumulus cells have a major role in this interaction, since they allow the action of some oocyte specific genes (GDF9) but also the control of its own metabolism and calcium movements. While ovulation will involve gonadotropins action on somatic cells, EGF-like factors recruited at the cumulus level will participate in this process. Finally we may suspect that improving the knowledge on oocyte-cumulus dialog will contribute to better define oocyte competence, while bringing some clues for in vitro maturation.

[Oocyte maturation: can oocyte competence be defined?]

Oocyte competence is acquired throughout oogenesis, via the interaction with somatic cells. The ability to reinitiate the meiotic process and undergo preimplantation development is progressively determined during the antral phase. It is well-known that these changes involve the nuclear and cytoplasmic compartments, respectively, but the underlying cellular and molecular mechanisms are still poorly understood. The oocyte undergoes a progressive series of morphological modifications as it grows and proceeds through the different stages of development. These structural rearrangements facilitate the increasing energy and nucleic acid synthesis requirements of the developing oocyte and are a prerequisite to the oocytes achieving meiotic and embryo developmental competence. The complexity of the orchestration of the events that control oocyte growth and ultimate acquisition of developmental competence is under continuous investigation. The present review describes some of the findings to date.

Meiotic segregation analysis in spermatozoa of pericentric inversion carriers using fluorescence in-situ hybridization

BACKGROUND

Pericentric inversions are structural chromosomal abnormalities resulting from two breaks, one on either side of the centromere, within the same chromosome, followed by 180 degrees rotation and reunion of the inverted segment. They can perturb spermatogenesis and lead to the production of unbalanced gametes through the formation of an inversion loop.

METHODS

We report here the analysis of the meiotic segregation in spermatozoa from six pericentric inversion carriers by multicolour fluorescence in-situ hybridization (FISH) and review the literature.

RESULTS

The frequencies of the non-recombinant products (inversion or normal chromosomes) were 80% for the inv(20), 91.41% for the inv(12), 99.43% for the inv(2), 68.12% for the inv(1), 97% for the inv(8)(p12q21) and 60.94% for the inv(8)(p12q24.1). The meiotic segregation of 20 pericentric inversions (including ours) is now available. The frequency of unbalanced spermatozoa varies from 0 to 37.85%. The probability of a crossover within the inverted segment is affected by the chromosome and region involved, the length of the inverted segment and the location of the breakpoints.

CONCLUSIONS

No recombinant chromosomes were produced when the inverted segment involved <30% of the chromosome length (independent of the size of the inverted segment). Between 30 and 50%, few recombinant chromosomes were produced, inducing a slightly increased risk of aneusomy of recombination in the offspring. The risk of aneusomy became very important when the inverted segment was >50% of the chromosome length. Studies on spermatozoa from inversion carriers help in the comprehension of the mechanisms of meiotic segregation. They should be integrated in the genetic exploration of the infertile men to give them a personalized risk assessment of unbalanced spermatozoa.

Existe-t-il un bénéfice au dépistage systématique de Chlamydia trachomatis, Mycoplasma hominis et Ureaplasma urealyticum dans les prélèvements génito-urinaires réalisés au cours d'un bilan d'infertilité ?

We conducted a prospective study on 100 couples consulting for infertility at the teaching Hospital of Tours, with the scope to determine if there is a benefit for systematic screening of Chlamydia trachomatis, Mycoplasma hominis and Ureaplasma urealyticum among genito-urinary specimen when exploring couples infertility. C. trachomatis was detected by PCR on sperm, endocervix and urine specimen. M. hominis and U. urealyticum were detected by culture on A7 agar medium and with minigaleries on sperm and endocervix specimen. Standard cultures were also performed on sperm, endocervix, vaginal and urine specimen. Only one specimen (sperm) was positive for C. trachomatis. Three percent of the specimen were positive for U. urealyticum (from which 2,5% of the sperm specimen). No specimen was positive for M. hominis. Our results show that screening of C. trachomatis, M. hominis and U. urealyticum is not systematically required for among check up of infertile couples, given the prevalence of chlamydiosis among the population studied. However, it would be interesting to perform it on a targeted population, according to anamnestic or clinical criteria. In addition, an important modification of vaginal flora was observed in 12% of cases, and 2 vaginosis were diagnosed; the putative consequences of this disequilibrium has to be further investigated.

Insémination intra-utérine : état des lieux chez l’humain

Despite its being used for a long time, intrauterine insemination (i.u.i.) remains debated as to its precise place and efficacy among assisted reproductive technologies. Data issued from the French Health Ministry inquiries are strictly limited to the number of cycles and the pregnancies and births including the multiple ones. Concerning 2000, more than 44,000 cycles were registered with 8% deliveries per cycle and 12% multiple pregnancies. Apart from the cervical female infertility which is considered to have the best prognosis with i.u.i., literature data remain controversial with male and unexplained infertility. Prospective randomized studies are rather scarce, particularly when considering the inclusion of untreated control population. Meta-analyses have been published for ten years, which allowed to better define the place of i.u.i. in patient management. However one may notice that the sperm cut-off parameters for male infertility and the respective contribution of i.u.i. and ovulation treatment do not allow develop some evidence-based guidelines for i.u.i. good practice. Quite all meta-analyses modulated their conclusions by addressing the need for large randomized controlled studies. Such a need seems now quite reinforced since results were until now expressed as pregnancy rate per cycle or pregnancy rate per couple, whereas single live birth rate and drop out rate are claimed to be taken into account nowadays. Moreover the level of controlled hyperstimulation is highly questionable with both hyperstimulation ovary syndrome and multiple pregnancy risks. Patients facing with failed i.u.i. cycles may turn to i.v.f. or i.c.s.i.. Interestingly data coming from the French national register (FIVNAT) did not show major differences between couples turning to i.v.f. (i.c.s.i.) after previously failed i.u.i. cycles or using directly i.v.f. (i.c.s.i.). Moreover the prognostic as evaluated on pregnancy rate per cycle was unchanged between such patients, which does not support some selection of patients by i.u.i. failure. Thus, although i.u.i. seems likely a cost-effective treatment in infertile couples, the precise conditions of its management (spontaneous or stimulated cycle, mono-, pauci- or multi-follicular induction) remain to be assessed. Indeed large controlled randomized studies including untreated group are required even if such design might have a non negligible cost. However these rather common treatments do have a high cost and any effort to rationalise them will have some economical impact. Another practical approach, although less ambitious, might consist in developing a per cycle registry which should allow to precise the French practice at a large national level.

Aromatase activity of human granulosa cells in vitro: effects of gonadotrophins and follicular fluid

The aim of this study was to assess whether human dominant follicular fluid has the ability to modulate aromatase activity and/or granulosa cell proliferation. Dominant follicular fluid was obtained by laparoscopy before the luteinizing hormone surge in naturally cycling women while granulosa cells used in the tests were obtained from in-vitro fertilization patients. Aromatase was measured by the tritiated water release assay, following a 48 h incubation with follicular fluid and serum, and expressed for 5x10(4) granulosa cells. The effects of a range of follicular fluid or serum concentrations (2.5, 5, 10 and 20%) were compared. A decrease in aromatase activity was observed when high follicular fluid concentrations (20%) (P < 0.01) were added. Low concentrations (2.5%) of follicular fluid significantly increased cell proliferation (P < 0.01) as compared to basal values (0%). No further stimulation was however observed when concentrations increased up to 20%. Further characterization of these compounds is required to understand how they may modulate maturation of the dominant follicle.

[Apoptosis in the male gonad]

Self-destruction of a cell following an internal or exogenous stimulus was a major concept which emerged in the early seventies. Such a phenomena is now reported to influence both embryonic development and tissue growth or renewing. Tumor growth as well as treatment may depend on apoptosis. This phenomena is identified using morphological as well as biochemical criteria. Spermatogenesis is a target for apoptosis which participate in the regulation of sperm production. Endocrine control of apoptosis in the seminiferous tubule was thoroughly studied, and some mechanistical studies dealing with oncogenes involved in apoptosis control have been done. Apoptosis is a key phenomenon in the control of sperm production.

[The future of male contraception: immunocontraception by preventing gamete interaction]

This paper summarize the main data relevant to the obtention of contraceptive vaccines based on spermatozoa as well as zona pellucida antigens. The development of novel forms of contraception is one way in which this global population problems can be tackled. The sperm as well as the oocyte antigens are studied as possible contraceptive vaccine candidates are the subject of this review.

[Preimplantation assessment: experimental data on animals and humans]

Assessing and/or improving the implantation prognostic remain a major goal for research studies as well as for teams doing embryo transfer in many species. Criteria for such a goal were focussed ten years ago and combined theoretically: -sensitivity for applying to one embryo; -clear cut-off for individual decision; -fastness to be suitable for embryo transfer in due time; -no toxicity or invasiveness for embryo; -finally some simple technical approach in order to be applies by a large number of teams. Moreover whatever may be qualitative or quantitative criteria, they should be relied to the final result as alive newborn. The more ancient way to appreciate embryo quality deal with the simple observation of morphological and kinetic criteria about embryo, but such non invasive approach was obviously limited, in spite of the positive influence of regular blastomers, absence of fragmentation and synchronization with time of transfer on implantation rate. The major transcriptional activity of human embryo developing between 6 and 8 cells stage, of course, were unassessed by transfer to day 2. Moreover the apparent quality of the embryo better reflected oocyte quality than embryo quality. Coculture development encompassed only partially such limitation. Using fluorescent probes, it was possible to evaluate some metabolic activity as well as membrane integrity, but such criteria revealed to be both invasive and uneasily reliable with developmental ability of the embryo. Methods dealing with glucidic, protidic or lipidic metabolisms are developed elsewhere, but revealed uneasy to apply, due both to their invasiveness or technical difficulties and their large inter-individual variability. Some hope has raised by the finding of growth factors or cytokines which are expressed by the embryo and/or embryotrophic but a lot of works remain to be down before an easy practical application.

[Ethical problems with the decision of refusal to a request for intra-conjugal in vitro fertilization]

What is our knowledge of the couples who suffer refusal of access to IVF when information is available for only 52% of the pregnancies obtained by IVF? With a retrospective study on IVF refusal datas in a centre where they are available, and an investigation by questionnaire in twelve other centers, the authors tried to evaluate the incidence of these refusal. IVF refusal concern 6 to 30% of the couples addressed, varying on a plurifactorial preselection; but a register including refusal is available in only four of the twelve centers. The main reason for refusal is maternal age. Only three of the twelve centers inquired have a real multidisciplinary staff for access decision. Moreover, if the twelve centers knows the future for the obtained pregnancies, it's true sometimes for only seven centers when IVF is unsuccessful, and never for ten centers when refusal of IVF. Assessment of IVF is incomplete, and improvement is needed based on: a better diffusion of the actual knowledge and its applications; a vast application of "ethical committee procedure" when decision for access is taken; and a global approach of IVF, considering refusal as well as success.

[Follicular fluid: role and importance in the preparation of spermatozoa for fertilization]

It has been demonstrated that the preovulatory follicular fluid creates a micro-environment which is of importance for normal sperm function. In this paper, we attempt to evaluate the role of human follicular fluid (HFF) on the fertilizing capacity of spermatozoa.

[Assisted procreation for male indication]

Strategy for male infertility looks like a compromise between diagnosis methods with their efficacy and complexity and treatment with their own risks, cost, efficacy. Infertility duration as well as woman's fertility play a key role for such a strategy. Definitive infertility without any correction (secretory azoospermia) will be proposed for alternate projects. Some situations may benefit from specific therapy (hypogonadotropic hypogonadism, anejaculations or retrograde ejaculation). More frequently male hypofertility is suspected with non specific sperm alterations, then assisted reproductive technologies will be discussed. Intra-cervical way artificial insemination with husband semen may be proposed in case of hypospadias, anejaculation, retrograde ejaculation, small volume ejaculate or self-cryostored semen, however negative post-coital test, positive crossed penetration test and positive post-insemination test need to be confirmed. Intrauterine way enhance fertilizing probability by discarding cervical step. It will be justified in case of negative post-coital test as well as crossed penetration test except that sperm preparation allowed to inseminate 500,000 to 1 million motile spermatozoa. Both rigorous monitoring and synchronism between insemination and ovulation enhance the efficacy of IU AIH which allowed a two to four fold increase in the pregnancy rate on a total of six cycles. In vitro fertilization for male factor represent around 15% of all IVF attempts. Both decrease in the fertilization rate and the increase in the pregnancy rate by transfer as compared with tubal factor are well accepted. The fertilization failure remain difficult to explain and need to be cautiously confirmed. Thus IVF represent an actual fertilization test but remain limited by the heterogeneity of parameters under "male factor".(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of freezing-thawing on the spermatozoon nucleus: a comparative chromatin cytophotometric study in the porcine and human species

Freezing-thawing effects on the nuclei of porcine and human spermatozoa were studied by determining native DNA percentage from fluorescence after acridine orange (AO) staining and by analyzing chromatin structure by a quantitative microspectrophotometric study of Feulgen-DNA complexes before and after freezing. The study of boar spermatozoa revealed no alteration in native DNA percentage after freezing. However, native DNA percentage decreased significantly in human spermatozoa. Feulgen-DNA content and sperm nuclear surface area decreased in both species after freezing. These results prompted us to hypothesize an overcondensation of sperm chromatin after freezing-thawing. This overcondensation may be related to the lower conception rates obtained with human and porcine semen after cryostorage via defective decondensation.