Pierre Vanderzwalmen

High implantation and pregnancy rates with testicular sperm extraction and intracytoplasmic sperm injection in obstructive and non-obstructive azoospermia

Thirty-two infertile couples with obstructive and non-obstructive azoospermia were included in this study. Testicular sperm extraction (TESE) was performed in 16 obstructive azoospermic cases where microsurgical sperm aspiration (MESA) or percutaneous sperm aspiration (PESA) were impossible because of totally destroyed epididymis and 16 non-obstructive azoospermia cases with severe spermatogenetic defect where the testicles were the only source of sperm cells. A total of 288 oocytes was obtained from 32 females and 84% were injected. The fertilization rates (FR) with 2 pronuclei (PN) and cleavage rate were 50.8 and 68.2% respectively. A total of 15 pregnancies was achieved (53% per embryo transfer), nine from the obstructive and six from the non-obstructive group. Four pregnancies resulted in clinical abortion (26.6%). The ongoing pregnancy rate was 39.2% per embryo transfer (ET) and 34.3% per started cycle. A high implantation rate was also achieved (26.6% in non-obstructive and 30% in obstructive azoospermia group). Using testicular spermatozoa in combination with ICSI in both obstructive and non-obstructive azoospermic groups, high implantation and pregnancy rates can be achieved.

Embryonic Stem Cells: Similarities and Differences Between Human and Murine Embryonic Stem Cells

The derivation of murine embryonic stem (mES) cell lines was reported for the first time in 1981 (Nature, 1981; 292:154–156; Proc Natl Acad Sci U S A, 1981; 78:7634–7638), and they have since proved to be a very useful tool with which to study mammalian development, which is characterized by pluripotency and differentiation. About 20 years later, the successful generation of human embryonic stem (hES) cell lines was described (Science, 1998; 282:1145–1147). Although mES and hES are derived from mammals, they cannot be looked at as being one and the same. While basic information for hES can be derived from mES, such information does not correspond on a one‐to‐one basis. This review gives an overview of the characteristics of embryonic stem cells with the main focus on the similarities and differences between human and mES cells.

Vitrification of hatching and hatched human blastocysts: effect of an opening in the zona pellucida before vitrification

Partially or completely hatched blastocysts were obtained from women with at least one previous cycle with failure of implantation. On day 5 after fresh embryo transfers, the remaining vitrification cycles (VC) were divided into three categories according to the types of blastocysts. The first group (20 VC) contained blastocysts (n = 38) with open zona pellucida (ZP), the second group of 34 VC contained blastocysts (n = 100) with both open and intact ZP, while the third group (14 VC) contained blastocysts with intact ZP (n = 39). Blastocysts were exposed to two mixtures of cryoprotectants. At 24 h after warming, survival rates of 82% (31/38), 72% (72/100) and 64% (25/39) were observed in the three groups respectively. Numbers of embryo transfers and blastocysts in the three groups respectively were 20, 31 and 13 transfers, and 31, 60 and 25 blastocysts, resulting in corresponding ongoing pregnancy rates per VC of 35, 26 and 21%. Blastocysts with a larger blastocoelic cavity survived vitrification better when they had partially or completely hatched. Survival rates significantly increased (P < 0.01) from 55 to 81% after warming expanded blastocysts with an intact ZP (n = 42) compared with an open ZP (n = 54) respectively. This study shows that partially or completely hatched blastocysts can be cryopreserved by a simple vitrification procedure using the hemi-straw as embryo carrier.

Two essential steps for a successful intracytoplasmic sperm injection: injection of immobilized spermatozoa after rupture of the oolema

A total of 740 cycles of intracytoplasmic sperm injection (ICSI) were performed: 625 cycles when < 6 x 10(5) total motile spermatozoa were harvestable from the ejaculate and 115 cycles in cases with a history of previous fertilization failure after classic in-vitro fertilization or subzonal sperm injection. An average of two pronuclei were observed in 63% of the injected oocytes, allowing 725 transfers of a maximum of three embryos (98%). Of 214 pregnancies initiated, 179 were established (25% of ICSI attempts). Because the fertilization rates from our initial 80 ICSI cycles were 2-fold less than those achieved previously, we changed the injection procedure and analysed, in 740 ICSI attempts, the importance of interfering technical factors and how to establish a successful ICSI programme. A remarkable change in the fertilization rate up to 68% (595 cycles) occurred when two steps in the injection procedure were performed well, i.e. immobilization of the spermatozoon and placement of the spermatozoon into the ooplasm after cytoplasmic aspiration into the pipette until oolema rupture. This immobilization, by touching the tail with the pipette, is mandatory for increasing the percentage of fertilization, even with totally non-motile spermatozoa (41%). Because aspiration of the cytoplasm is an invasive part of the ICSI procedure and influences the quality of the embryos, it is essential to reduce the amount of cytoplasm drawn into the pipette. This could be attained by using a spikeless injection pipette with the smallest possible internal diameter.

Prevention of multiple pregnancies in an in vitro fertilization program

OBJECTIVE To limit the high number of multiple pregnancies in an IVF program. SETTING In Vitro Fertilization Laboratory, Fertility Department, Public Hospital. INTERVENTIONS The number of embryos transferred was limited to two instead of three. RESULTS Limiting the number of embryos transferred to only two did not influence the take home baby rate but eliminated triplet and quadruplet gestations. Moreover, the number of patients with good quality supernumerary embryos available for cryopreservation increased. CONCLUSIONS To reduce the high frequency of multiple gestations in an IVF program, the number of embryos replaced should be limited to a maximum of two.

Open versus closed oocyte vitrification system: a prospective randomized sibling-oocyte study

Vitrification has been successfully applied in the cryopreservation of oocytes and embryos. It can be achieved either by direct (open system) or indirect (closed system) contact with liquid nitrogen. Unlike embryo vitrification, few reports have been published regarding oocyte vitrification in closed systems. In order to validate the effectiveness of a closed and aseptic vitrification approach for oocyte cryopreservation, a prospective, randomized study was performed. Sibling oocytes donated from the same donor were randomly and equally assigned into closed or open vitrification groups. A total of 75 vitrification-warming cycles were performed in each group. Apart from the survival rate (82.9% versus 91.0%, P<0.05), no statistically significant differences were observed in pregnancy (β-human chorionic gonadotrophin positive) (42.7% versus 33.3%), clinical pregnancy (36.0% versus 28.0%), implantation (13.8% versus 10.1%), ongoing pregnancy (33.3% versus 24.0%) and live birth (36.0% versus 24.0%) rates between the closed and open groups, and 27 and 18 healthy babies were born, respectively. This study shows that the replacement of the open vitrification system by a closed system has no impact on clinical pregnancy and implantation rates. Therefore, the closed vitrification system provides an aseptic alternative to the open method for oocyte vitrification.

The combination matters - distinct impact of lifestyle factors on sperm quality: a study on semen analysis of 1683 patients according to MSOME criteria

BackgroundPoor sperm quality can negatively affect embryonic development and IVF outcome. This study is aimed at investigating the influence of various lifestyle factors on semen quality according to MSOME (motile sperm organelle morphology examination) criteria.Methods1683 male patients undergoing assisted reproductive technologies (ART) in our clinic were surveyed about their age, BMI (body mass index), ejaculation frequency, nutrition, sports, sleeping habits and social behavior. Semen samples were collected and evaluation of semen parameters according to MSOME and WHO criteria was performed. Results were grouped and statistically analyzed.ResultsAlthough single parameters had minor effects on sperm parameter, the combination of age, BMI, coffee intake, ejaculatory frequency and duration of sexual abstinence were identified as factors having a negative effect on sperm motility. Additionally, we could demonstrate that MSOME quality was reduced. The negative impact of age, BMI and coffee intake on sperm quality could be compensated if patients had a high ejaculation frequency and shorter periods of sexual abstinence.ConclusionsCombinations of adverse lifestyle factors could have a detrimental impact on sperm, not only in terms of motility and sperm count but also in terms of sperm head vacuolization. This negative impact was shown to be compensated by higher ejaculation frequency and a shorter period of sexual abstinence. The compensation is most likely due to a shorter storage time in the male gonads, thus reducing the duration of sperms’ exposure to reactive oxygen species (ROS).

Cytoskeletal analysis of human blastocysts by confocal laser scanning microscopy following vitrification

BACKGROUND Vitrification of human blastocysts is being used increasingly to cryopreserve supernumerary embryos following IVF. In this study, we investigate the effects of aseptic vitrification on the cytoskeleton and development of human blastocysts, by analysing survival rates and spindle and chromosome configurations by fluorescence and confocal laser scanning microscopy. METHODS A total of 55 fresh blastocysts and 55 day 5 dimethylsulphoxide/ethylene glycol vitrified blastocysts, which were allowed to remain in culture for 24 h post-warming, were rapidly fixed in ice cold methanol, and immunostained with an a-tubulin antibody to visualize microtubules in combination with antibodies against acetylated tubulin (to visualize spindles, poles and mid bodies), gamma tubulin (to identify spindle poles) and 4(6-diamidino-2-phenylindole) to visualize DNA. RESULTS In total, 213 spindles were analysed in the control (fresh) group of which 183/213 (85.9%) were normal, 20/213 (9.4%) were abnormally shaped, 9/213 (4.2%) were multipolar and 1/213 (0.5%) was monopolar. A total of 175 spindles were analysed in the vitrified group, of which 120/175 (68.6%) were normal, 39/175 (22.3%) were abnormally shaped, 10/175 (5.7%) were multipolar and 6/175 (3.4%) were monopolar. The incidence of multipolar spindles was similar in the two groups, but the level of abnormally shaped spindles, often associated with chromosome lagging, or congression failure, was significantly higher in the vitrified group compared with the fresh group (P< 0.05). CONCLUSIONS The high survival rate following thawing and the large proportion of normal spindle/chromosome configurations suggests that vitrification at the blastocyst stage on Day 5 does not adversely affect the development of human embryos and the ability of spindles to form and continue normal cell divisions. However, there was a significantly higher incidence of abnormal spindles in the vitrified group compared with the fresh group, notably of spindles with a focused and an unfocused pole as well as chromosome bridging and disorganized middle spindle fibres at telophase. Further investigation is warranted to elucidate the mitotic stages that are more vulnerable to damage during vitrification, the fate of the abnormal spindles and any potential effects that may be reflected on the chromosomal constitution of the developing blastocysts.

Individual demands of human embryos on IVF culture medium: influence on blastocyst development and pregnancy outcome

The elucidation of the metabolic requirements of human embryos in vivo or in vitro remains, despite being intensively investigated, a work in progress. The adoption of extended embryo culture to the blastocyst stage during the last decade has entailed new challenges. With the increased attention to culture media formulations, more evidence on the sensitivity of embryos to their early environmental conditions is accumulating which might affect phenotype and developmental potential. A retrospective study was conducted that comprised 286 IVF cycles to evaluate the effect of two different culture media on blastocyst development and pregnancy outcome. Embryos were either cultured in a one step or a sequential medium. Higher fertilization rates and augmented blastocyst rates as well as higher implantation rates were observed when embryos were cultured in one step medium (P<0.05). Interestingly, the transfer of two embryos where one embryo was cultured in either medium resulted in a significantly higher rate of twin pregnancies. Although multiple pregnancies should be avoided in assisted reproduction treatment to reduce risks for offspring and mother, this higher frequency of twin pregnancies resulting from the transfer of embryos derived from different culture media suggests that each embryo makes individual demands on its early environment.

Intracytoplasmic sperm injection, fertilization, and embryo transfer after retrieval of spermatozoa by testicular biopsy from an azoospermic male with testicular tubular atrophy

OBJECTIVE To achieve fertilization and cleavage by spermatozoa retrieved by testicular biopsy from a male with testicular tubular atrophy. DESIGN Clinical trial. SETTING Private reproductive institute. PATIENT Azoospermic male with demonstrated testicular tubular atrophy and almost complete spermatogenic arrest. INTERVENTION Open biopsy retrieval of testicular tissue and sperm followed by intracytoplasmic sperm injection. MAIN OUTCOME MEASURES Fertilization and cleavage. RESULTS One four- to six-cell embryo was formed after intracytoplasmic sperm injection of five eggs with extruded polar bodies by retrieved sperm. CONCLUSION Intracytoplasmic sperm injection after testicular sperm aspiration may be attempted in cases with severely decreased spermatogenesis and result in fertilization, cleavage, and embryo transfer.