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Biomedical subjects

C Wittemer

Publications and source records attributed to C Wittemer.

At least 19 recordsLinked to original sources
PubMed2007

[Embryo donation in France: practice and difficulties. Strasbourg's experience].

OBJECTIVE: The aim of this study was to present the situation of embryo donation in France and around the world, to expound the difficulties of its practice and the results obtained in our centre 3 years after the introduction of this procedure. PATIENTS AND METHODS: Embryo donation in France is controlled by implemented decrees published between 1999 and 2004. The couples, who have stored frozen embryos since at least two years, were contacted for a pluridisciplinary medical consultation. The indication of embryo donation was evaluated for the recipients through a pluridisciplinary approach. RESULTS: Among the interviewed couples, 16.7% have chosen embryo donation but only half of them have completed the procedure (6% of the couples with frozen embryos). The main indications for embryo donation were a double sterility, unexplained genetic disease, ART failures (poor fertilization or bad embryo quality) and oocyte donation when the delay was too long for the couples. The pregnancy rate was 28.6% after the 21 first embryo transfers. DISCUSSION AND CONCLUSION: The results of embryo donation confirm the international experience both considering the poor number of donated embryos, medical indications and results. Embryo donation has its place among ART techniques, but one should not ignore the general debate on ethical questions raised by this procedure.

Embryo Disposition↗
PubMed2005

Seminal haploid cell detection by flow cytometry in non-obstructive azoospermia: a good predictive parameter for testicular sperm extraction.

BACKGROUND: Testicular sperm extraction (TESE) associated with ICSI gives patients suffering from non-obstructive azoospermia (NOA) the possibility of becoming a father. The success rate of TESE based on sperm recovery is approximately 50%, and the commonly used non-invasive parameters are not predictive enough. Only the invasive testis biopsy has a good prognostic value. The aim of this study was to evaluate the prognostic value of the detection of seminal haploid cells by flow cytometry (FCM) in order to avoid unnecessary testicular biopsy. METHODS: For 37 NOA patients undergoing testicular biopsy, we measured testis size, serum FSH and inhibin B levels and carried out seminal cytology, seminal FCM analysis and histological examination. RESULTS: Sperm were found in 18 biopsies. These results were correlated with cytology, FCM analysis and the histological examination. FCM was more sensitive than cytology (100 versus 59%) but less specific (67 versus 83.5%) whereas the histological observation of complete spermatogenesis appeared to be less sensitive (50%) but more specific (100%). CONCLUSION: Detection of seminal haploid cells by FCM appears to be an interesting non-invasive technique which can predict TESE results and improve the management of NOA patients.

Adult↗
PubMed2004

[Abnormal bacterial colonisation of the vagina and implantation during assisted reproduction].

OBJECTIVE: To evaluate the efficiency of our treatment of vaginal infection for couples included in an IVF program. PATIENTS AND METHODS: Microbiologic screening of vaginal flora and semen has been performed one month prior to in vitro fertilization for 951 couples in 2000. Antibiotic treatment was prescribed in case of positive culture. RESULTS: Positive microbial growths were observed from endocervical and vaginal cultures in 218 women (22.9%). The clinical pregnancy rate was 30.29% in the group of patients without growth and 30.27% in the group with positive microbial growth. The implantation rate was significantly diminished in case of bacterial growth: 14.6 compared to 19.3% (P <0.02) for sterile endocervical culture. Five main bacterial species were found at the cervical level: Candida albicans (69 cases), Ureaplasma urealyticum (49 cases), Gardnerella vaginalis (43 cases), Streptococcus B or D (24 cases) and Escherichia coli (22 cases). Positive cultures from both vagina and semen were observed for 77 couples whose clinical pregnancy rate was 19.5 vs 36.2% in case of vaginal infection alone (P <0.01) with a spontaneous miscarriage rate of 46.7 compared to 17.6% (P <0.01). DISCUSSION AND CONCLUSION: Endocervical microorganisms, even treated with adapted antibiotics, may affect embryonic implantation. Positive culture from both female and male partner may enhance this negative effect. In this case, the best strategy would be to cancel the IVF treatment.

Bacterial Infections↗
PubMed2003

[Towards a single embryo transfer: predictive value of uterine and embryological parameters in assisted reproduction outcome].

OBJECTIVE: The transfer of a single embryo would avoid obstetrical and neonatal complications due to multiple pregnancies. We studied the clinical value of both uterine and embryological parameters to define precise conditions allowing a single embryo transfer without decreasing pregnancy rates. PATIENTS AND METHODS: Endometrial parameters expressed by a uterine score together with biological criteria of 131 in vitro fertilization or intracytoplasmic sperm injection attempts were retrospectively analysed. RESULTS: Two hundred and sixty-two day-3 embryos were replaced through 131 transfers. Fifty-seven pregnancies were induced and 16 twins were obtained. The clinical pregnancy rate was 35.9% and the embryonic implantation rate 24.0%. After the transfer of two embryos, successful implantation was determined by the occurrence of top-quality embryos and simultaneously by a receptive endometrium. The uterine pulsatility index was significantly decreased for twin compared to singleton pregnancies. DISCUSSION AND CONCLUSION: This study confirms that a uterine score constitutes a powerful tool for evaluating the uterine receptivity. This parameter has to be taken into account as well as the embryonic quality, in order to optimise the success rate. Young patients with at least two top-quality embryos available, a high uterine score and a low pulsatility index, have a high risk of multiple births and are suitable for a single-embryo transfer.

Adult↗
PubMed2002

[Evolution of homocysteine during ovarian stimulation for IVF or ICSI].

OBJECTIVE: To determine the homocysteine evolution during ovarian stimulation in IVF or ICSI protocols and in, a second time, to evaluate the role of hyperhomocysteine as thrombotic risk factor for the treated patients. MATERIAL AND METHODS: Plasma homocysteine was determined three times for each of 31 women included in an IVF/ICSI program. Dosages were realised before stimulation, after gonadotrophin-releasing hormone agonist treatment (GnRH) and on the day of hCG injection. Vitamin B12 and folates were determined before stimulation. In case of hyperhomocysteinemia, a research of APCR (Activated Protein C Resistance) was realised. RESULTS: Five hyperhomocysteinemia cases were discovered (16.12% of studied population). APCR was found in a patient with hyperhomocysteinemia (14 mumol/L, before stimulation). Molecular biology has confirmed an heterozygous mutation of factor V Leiden. During the ovarian stimulation the evolution of homocysteine was independent of the 17 beta oestradiol evolution. CONCLUSION: The prevalence of hyperhomocysteinemia was not significative according to the limited size of the studied population. The increase of oestradiol during induction protocols is unrelated to the homocysteine level. This work must be continued with largest population to have better knowledge of the prevalence of hyperhomocysteinemia among women included in ovarian stimulation protocols.

Adult↗
PubMed2001

Allele-specific amplification for preimplantation genetic diagnosis (PGD) of spinal muscular atrophy.

We have developed a new allele-specific amplification method for the preimplantation genetic diagnosis (PGD) of spinal muscular atrophy (SMA; Werdnig-Hoffmann disease) from a single cell. This method is based on the detection of the deletion of exon 7 of the telomeric copy of the survival motor neurone (SMN(t)) gene. An oligonucleotide was designed to be specific to the SMN(t) nucleotidic sequence with exonic mismatch G (for SMN(t))-->A (for SMN(c)) at its 3' end. This test produces reliable PCR products in 95% of single lymphoblasts (85/88) tested as well as in 16/16 blastomeres from normal controls. Specificity analysis showed that we were able to detect homozygous deletion of the SMN(t) gene in 99% of single lymphoblasts (103/104) from a SMA patient. No contamination was detected in 68 blanks tested. Multiple cell and DNA dilution analysis revealed that the test is accurate and specific up to 100 pg DNA and should thus also be suitable for PGD at the blastocyst stage. This rapid procedure requires a single round of fluorescent PCR and no restriction digestion, while previously described single cell methods include nested PCR followed by restriction enzyme digestion. Two PGD cycles for SMA using this procedure were performed in our centre.

Adult↗
PubMed2001

[Twin birth after preimplantation diagnosis for cystic fibrosis].

OBJECTIVE: Cystic fibrosis is a common autosomal recessive disease most often caused by a deletion (delta F508) in the CFTR gene. It is the most common indication for preimplantaion genetic diagnosis which allows genetic analysis of embryos obtained after in vitro fertilization and transfer of unaffected embryos into the patient's uterus. PATIENTS AND METHODS: We report the first preimplantation genetic diagnosis performed in Strasbourg for a couple at risk of having a child affected by severe cystic fibrosis due to a homozygous delta F508 mutation. Three days after fertilisation, embryos obtained after intra-cytoplasmic testiculare sperm injection were biopsied and analysed. PCR amplification of the genomic fragment containing the delta F508 locus allowed detection of the delta F508 mutation and transfer only of the unaffected embryos. RESULTS: Three embryos were transferred after this preimplantation genetic diagnosis. A twin pregnancy was obtained and the babies born from this cycle are both exempt from the mutation. CONCLUSIONS: Preimplantation genetic diagnosis for the cystic fibrosis delta F508 mutation is now available in our centre. In this report, we could resolve both the problem of infertility and the risk of transmission of a severe form of cystic fibrosis. Preimplantation genetic diagnosis is also available for other mutations involved in cystic fibrosis and also for other genetic diseases.

Adult↗
PubMed2000

A quantitative and morphological analysis of oocytes collected during 438 IVF cycles.

PURPOSE: Our purpose was to determine if the number of retrieved oocytes, oocyte maturity, morphology, and other embryological parameters are related to the outcome of treatment. METHODS: This retrospective study on 438 IVF cycles analyzes the numbers of retrieved oocytes, fractured zona oocytes, germinal vesical-stage oocytes, normally and abnormally fertilized oocytes, pregnancy rate, age of female partner, ovarian stimulation protocol, day of hCG injection, and serum estradiol concentration. RESULTS: (1) Pregnancy rate increases with an increase in the number of retrieved oocytes, (2) a high incidence of fractured zona pellucida oocytes has a negative effect on fertilization rate but none on pregnancy rate, (3) a high incidence of immature oocytes is associated with improved fertilization and pregnancy rates, and (4) an inverse relationship between the presence of immature oocytes and oocytes with fractured zona pellucida is suggested. CONCLUSIONS: Precise oocyte assessment in IVF cycles provides informations useful for the analysis and improvement of ovarian stimulation protocols.

Adult↗
PubMed2000

Does body mass index of infertile women have an impact on IVF procedure and outcome?

PURPOSE: The objective was to explore whether body mass index (BMI) of women related to the different parameters of the in vitro fertilization (IVF) procedure and outcome. METHODS: This retrospective study on 398 couples analyzed epidemiological features, characteristics of ovarian stimulation, number and quality of retrieved oocytes, as well as pregnancy outcome according to three groups of BMI values: BMI < 20, 20 < or = BMI < 25 and BMI > or = 25 kg/m2. RESULTS: The prevalence of underweight and overweight women was 21.8% and 22.3%, respectively. The mean ratio follicle-stimulating hormone-luteinizing hormone increased significantly according to BMI. An increase in the mean number of consummated gonadotropin ampoules together with a decrease in the number of collected oocytes was observed in long stimulating protocol cycles when BMI > or = 25 kg/m2. The same observations were made in short stimulation protocol cycles of BMI < 20 and > or = 25 kg/m2. No significant difference could be found in clinical pregnancy and miscarriage rates between underweight, normal weight, and overweight patients. CONCLUSIONS: Both underweight and overweight have negative effects on IVF parameters and outcome leading to decreased chances of pregnancy.

Adult↗
PubMed2000

Zygote evaluation: an efficient tool for embryo selection.

One of the main problems concerning IVF units is the need to decrease the occurrence of multiple pregnancies in their practice without affecting the overall success rate. Different embryological parameters concerning every step of the early embryo development are known to have some predictive value for implantation potential. In this prospective study, a pronuclear scoring system was used to classify zygotes into six patterns from 0 to 5. Cleaved, day 3 embryos developed from pattern 0 zygotes, which was described as the normal pattern, were transferred when available. For each zygote pattern, the subsequent embryological development was analysed. Pattern 0 zygotes led to significantly more 'good quality' embryos with higher implantation potential than embryos developing from the other zygote patterns (P < 0.01). Embryo transfers including at least one pattern 0 resulted in significantly more pregnancies than transfers without any pattern 0 zygotes (39.3 versus 19.7%, P < 0. 01). No relationship between clinical parameters (age of female partner, infertility cause) and zygote pattern distribution was demonstrated.

Aging↗
PubMed2000

Histological and genetic analysis and risk assessment for chromosomal aberration after ICSI for patients presenting with CBAVD.

Intracytoplasmic sperm injection (ICSI) has opened a new field in the treatment of male infertility, leading to a debate concerning its genetic safety. In this study we present an analysis of 11 patients presenting congenital bilateral absence of the vas deferens (CBAVD). In all 11 cases, genetic counselling, histological analysis of testicular biopsies, cystic fibrosis transmembrane conductance regulator (CFTR) mutation screenings of both partners and spermatozoa three-colour fluorescent in-situ hybridization (FISH) analysis were performed. A total of 31 CFTR mutations were screened and mutations were found in eight out of 11 cases, with DeltaF508 being the most common mutation found. Histological analyses showed that seven out of 11 patients had normal tubule/membrane/interstitium (TMI) and Johnsen scores, while the remaining four patients had mild impairment of testicular parenchyma. The average aneuploidy rate was 6.8 +/- 3.9% compared with two control subjects with 4.4 and 5.4% aneuploidy rates respectively, using FISH analysis. After ICSI, the fertilization and pregnancy rates were 66.2 and 22.7% respectively. Thus, in our case of CBAVD, the risk of chromosomal aberration following ICSI, in the absence of a CFTR mutation in the male patient and/or in his partner, was not higher than in normal fertile men. Furthermore, the pregnancy success rate following ICSI of these CBAVD patients was comparable to the general ICSI population, even when histological analysis showed limited spermatogenesis.

Adult↗
PubMed2000

[Future perspectives: oocyte cryopreservation and in vitro maturation].

After treatment for neoplasia, a young patient can nowadays hope to be pregnant. The aim of this paper is to establish a review of the literature about cryopreservation of oocytes and ovarian tissue, and in vitro maturation of oocytes. These studies also concern patients for which ovarian stimulation is difficult, such as PCOS. These techniques could also facilitate the creation of an oocyte bank as the one already existing for sperm. So far the main studies published, in spite of very timid first results, allow us to look to a great future for cryopreservation and in vitro maturation of oocytes.

Cryopreservation↗
PubMed1998

[Therapeutic strategies in azoospermia: management].

ICSI allows use of epididymal or testicular sperm in case of azoospermia. The aim of this study is to propose an algorithm for the management of the different situations of azoospermia according to our personal experience and according to data of literature. The following points are discussed: epididymal or testicular origin of sperm, retrieval technique, contribution of freezing, interest of in vitro culture, side effects and need of a preliminary biopsy. So a therapeutic strategy adapted to both types of azoospermia obstructive and non obstructive can be proposed.

Biopsy↗
PubMed1997

Prognostic value of objective semen parameters in an in vitro fertilization program.

PURPOSE: The basic semen parameters seem to have a limited predictive value in male fertility. Could other objective sperm analyses be helpful in the choice of the most adapted assisted procreation technique? METHODS: This study concerns 78 infertile couples with insemination failures. For each semen, 21 objective parameters are analyzed in fresh semen and after sperm selection procedure. The 78 couples are then included in an IVF protocol and classified into two groups: fertile (at least one cleaved embryo is obtained) and infertile. RESULTS: Using multiple variant discriminant factorial analysis, we have found nine nonconventional parameters which induce us to define two classes of semen. These two classes fit with the classification into fertile and infertile groups in 74.4% of the cases. CONCLUSIONS: So these parameters allow us to predict the chance of obtaining embryos during an IVF trial and to choose for each couple the most appropriate technique: IVF or ICSI.

Acrosin↗
PubMed1996

Could in vitro fertilization with a modified sperm preparation technique be an option to micromanipulations?

PURPOSE: This study evaluated the efficiency of in vitro fertilization with a modified sperm preparation technique for male infertility, to avoid systematic recourse to ICSI. METHODS: The sperm function stimulants pentoxifylline, 2-deoxyadenosine, and follicular fluid were used during the sperm preparation of IVF trials for two groups of patients: couples with long-standing infertility and previous IVF failures and couples with male-factor infertility scheduled for their first treatment. RESULTS: Forty-nine attempts were performed in the first group. The overall fertilization rate (percentage of zygotes with two pronuclei 18 hr after sperm insemination) was 30% and the clinical pregnancy rate per transfer was 33%. For the second group, 30 attempts were performed. The fertilization rate was 29.6% and the clinical pregnancy rate was 62.5% per transfer. The total number of recovered motile sperm appears to be a significant parameter: a cutoff value of 0.25 million motile sperm recovered after capacitation treatment has a good prognostic value for choosing between IVF with sperm enhancers and ICSI. CONCLUSIONS: The described modified IVF could constitute an alternative to the systematic use of ICSI.

Adult↗
PubMed1996

Identification of hyaluronic acid and chondroitin sulfates in human follicular fluid and their effects on human sperm motility and the outcome of in vitro fertilization.

This study measured glycosaminoglycans (GAGs) in human follicular fluid (hFF) obtained from patients undergoing hormonal stimulation with combined GnRH agonist followed by gonadotropin hormone (hMG or FSH) for in vitro fertilization (IVF). The GAGs were partially characterized through the use of various mucopolysaccharidases and then their effects tested on human sperm motility. In hFF, the GAG and protein concentrations were 4.4 +/- 1.3 mg/L and 32.6 +/- 3.2 g/L respectively. Chondroitins (CS) and hyaluronic acid (HA) significantly stimulate sperm motion in comparison to the control. The oocytes inseminated with GAGs-pretreated spermatozoa showed a significantly higher rate of cleavage and pregnancy or delivered number. The present results suggest that hFF is a rich source of sulfated glycosaminoglycan (CS), and non-sulfated glycosaminoglycan (HA). The stimulatory effects of hFF on human sperm motility may well depend on CS and HA. GAGs pretreated sperm may enhance the fertilizing ability of spermatozoa and thus the IVF outcome.

Chondroitin Sulfates↗