[Single embryo transfer : impact of new Belgian legislation on the results of the Clinic of Fertility of the Erasme Hospital]

With the progress made in the treatments of assisted reproduction, implantation and pregnancy rates have increased. This evolution has led to increase the rates of multiple pregnancies in the general population. Considering maternal and fetal risks related to multiple pregnancies it was necessary to reduce their incidence. Several efforts have been tried, in particular the limitation of the number of embryos transferred to 2. This reduced the incidence of triplets but that of twin remained unchanged, which convinced the clinicians of the need to reduce further the number of embryo transfer. In Belgium a new policy of transfer was established by a law introduced since the 01/07/2003 aiming to reduce the costs related to the twin pregnancies and to increase the reimbursement of IVF treatments. We have studied the impact of this policy on the results at the clinic of Erasme. Two periods were compared : from 01/01/2001 to 30/06/2003 where the majority of the transfers was transfers of 2 embryos (56.8 %) and from 01/07/2003 to 31/12/2004 where the majority of the transfers was transfers of a single embryo (53.7 %) (p < 0.001). The rates of single embryo transfer were 12.5 % and 53.7 % respectively (p < 0.001). The rates of clinical pregnancies were 33.2 % and 27.3 % respectively (p < 0.001), on the other hand the percentage of twin pregnancies has strongly decreased from 29.9 % to 11.4 % (p < 0.001). The rate of frozen embryos has increased from 22 % policy seems to achieve its goals to the detriment of a reduction of the success rates. Nevertheless, the increase in the number of frozen embryos should allow, after thawing and transfer, to compensate at least partially this reduction of the pregnancy rate.

[What kind of support do couples expect when undergoing IVF treatment? Study and perspectives]

OBJECTIVES

To assess the management of the supportive aspects of treatment for couples having attempted an in vitro fertilization treatment.

MATERIAL AND METHODS

Three groups of couples were contacted by questionnaire (successful treatment, unsuccessful treatment treatment, outcome still unknown).

RESULTS

48% considered it necessary to offer psychological support after the diagnosis. 80% considered it difficult to have a thorough representation of the physical aspects of an In Vitro Fertilization treatment but mostly they were surprised by their lack of an accurate emotional representation. All couples expected an availability and receptiveness from the infertility team but the unsuccessful treatment group was less satisfied and felt significantly (P < 0.001) less well supported. The most difficult moments mentioned were the numerous moments of waiting and the announcement of the final result. Emotional support was regularly provided by the nurses but 20% wanted psychological counselling. Two thirds of all couples considered that a psychological follow-up should be proposed to couples for whom the treatment remain unsuccessful.

CONCLUSIONS

Results show the need for better emotional preparation of couples. As for the emotional support during treatment, the need for psychological counselling appears after the diagnosis of infertility as well as a constant demand of availability and empathy on behalf of the team. Post-treatment counselling may be particularly important also. Failure as well as lack of support at that time seemed to colour the way couples regard the whole support provided during treatments.

Selection of good embryos for transfer depends on embryo cohort size: implications for the 'mild ovarian stimulation' debate

Embryo quality evaluated by the embryo morphology is a critical parameter in human in-vitro fertilization (IVF) and embryo transfer. It determines which and how many embryos will be replaced, as pregnancy rates are directly related to number and quality of transferred embryos. This retrospective analysis included 1301 IVF and embryo transfer cycles to identify which factors influenced embryo quality. Embryo quality did not correlate with maternal age, causes of infertility, ovarian stimulation parameters or embryo cohort size. However, the mean score of transferred embryos was significantly higher for patients with more than five embryos compared to fewer than five embryos (P < 0.001), irrespective of maternal age. Patients tended to produce a similar embryo quality from cycle to cycle, r = 0.33 (P < 0.001) for the embryo cohort and r= 0.47 (P < 0.001) for the transferred embryos. Poor embryo morphology probably reflects oocytes with compromised development competence and could be an independent factor of infertility. Furthermore, a large embryo cohort was the main factor increasing the chances of at least one good embryo in the cohort.

[Diminishing the risk of multiple pregnancies in in vitro fertilization: from selective transfer of two embryos to that of one blastocyst?]

The risk of multiple pregnancy after IVF needs to be drastically reduced. Several policies can be applied including the transfer of a maximum of three embryos to all patients, the fertilization of a maximum of three oocytes or a selective reduction of the number of transferred embryos. The first policy previously applied at the Fertility Clinic at Erasme Hospital until 1996, transferred two good quality embryos to patients with at least three good embryos. If this policy demonstrated that patients with two transferred embryos had similar chances of pregnancies compared to patients with three transferred embryos, it failed to sufficiently decrease the number of multiple pregnancies. The second policy applied since 1997, transferring a maximum of two average or good embryos to all patients aged under 35 years and with less than 3 previous attempts, demonstrated that while preserving the chances of pregnancy for these patients, it decreased by 20% the number of multiple pregnancies and almost eliminated triplets. With the improvement of culture media, it is now possible to culture embryos in vitro for a longer period and therefore transfer embryos with proven viability at a time corresponding more to in vivo physiological conditions. The implantation rates for these embryos, for patients with at least 4 previous attempts can reach 40%. If these results persist, it would be possible to transfer blastocysts to all patients and perhaps move on to the replacement of a single embryo, a policy that will practically eradicate all multiple pregnancies.

[In vitro fertilization at the Erasme Hospital: 10 years and 1000 pregnancies later...]

This contribution summarize ten years of in vitro fertilization of clinical work. Activity growth, improvements of results (mean fertilization rate increased from 45% to 58%, fertilization failure dropped from 18% to 7%, pregnancy chances gains 9% to reach 44% per trial) and new treatments possibilities (severe male infertility) thanks to the ICSI technic were the major characteristics of this last ten years. The original anonymous oocyte donation program with donors permutation initiated as soon as 1990 has imposed itself due to it's exceptional efficiency with a pregnancy rate of 95% per oocyte pick up on a population of 46 donors and 145 recipient cycles. Thanks to the large population studied (4028 cycles, 1071 pregnancies), the tendencies in human fecundity (impact of age) and the risks linked to multiples pregnancies could be highlighted, stressing the importance of future developments presented in the other contributions following this general presentation of results.

Comparison of two elective transfer policies of two embryos to reduce multiple pregnancies without impairing pregnancy rates

A first elective transfer policy of two embryos based solely on embryo morphology was compared to a more restrictive policy transferring two embryos to all patients aged < 35 years with less than three previous cycles to reduce the incidence of multiple pregnancies. With a significant reduction in the number of triple transfers from 72.4 to 44.3%, the delivery rates were similar for both policies, 31 and 32.1%. However, the multiple pregnancy rates per transfer significantly decreased from 12.5 to 7.8% (P < 0.05). Of 99 pregnancies, only 24.2% were multiple including 1% of triplets compared to 40.7% multiple pregnancies including 6.7% of triplets for the first policy. Forty-eight transfers of two average embryos with the new policy were compared to 264 transfers of three average embryos with the old policy. Multiple pregnancy rates per transfer were significantly reduced by a third from 23 to 8% (P < 0.05) without a reduction of the pregnancy rates (42 and 48%). This study demonstrated that elective transfer of two embryos reduced the number of multiple pregnancies without impairing the pregnancy rates even with the transfer of average embryos.

Is matching between women and donors feasible to avoid cytomegalovirus infection in artificial insemination with donor semen?

Cytomegalovirus (CMV) is the most common cause of congenital infection responsible for neonatal mortality, morbidity and later sequelae. Primary infection in the first half of pregnancy seems to have the worst outcome. CMV has been frequently recovered from human semen. In the setting of artificial insemination with semen donors, matching recipients and donors for CMV antibodies with the purpose of reserving seronegative semen for seronegative women is a recommended strategy to avoid the risk of a primary maternal CMV infection during pregnancy. We have reviewed the CMV seroprevalence in semen donors and candidates for insemination in our centre, and compared it with the CMV seroprevalence of blood donors. Without matching for CMV antibodies, the risk of a seronegative recipient being inseminated with seropositive semen was 21%. The same risk calculated for blood donors was 17%. Matching semen donors and recipients for CMV antibodies is possible as, in our study, 48% of the recipients and 55% of the donors were seronegative. During serological follow-up of CMV seronegative individuals in the fertility centre, no seroconversion was observed among donors; two seroconversions occurred in recipients, but not in relationship to therapeutic inseminations.

Short-term medical complications of 1500 oocyte retrievals for in vitro fertilization and embryo transfer

OBJECTIVE

To evaluate the different short-term complications after in vitro fertilization and embryo transfer.

DESIGN

a retrospective study on 7 years in the fertility clinic of an university hospital.

MATERIALS AND METHODS

Short-term medical complications were analysed after 1500 transvaginal ultrasonographically guided oocyte retrievals.

RESULTS

Ovarian hyperstimulation syndrome (1.8%), pelvic infections (0.4%), intraperitoneal bleeding (0.2%) and adnexal torsions (0.13%) were observed. One case of adnexal torsion occurred during pregnancy (0.18%). Two unusual case of bowel endometriosis were encountered (0.13%).

CONCLUSIONS

Short-term medical complications after in vitro fertilization and embryo transfer are rare (2.8%). This contrast with the high rate of multifetal pregnancies which increases maternal and perinatal morbidity and mortality and must be considered as the major complication of in vitro fertilization treatment.

Glass wool column filtration, an advantageous way of preparing semen samples for intracytoplasmic sperm injection: an auto-controlled randomized study

The characteristics of the glass wool filtration technique for the preparation of semen samples in an intracytoplasmic sperm injection programme (ICSI) were compared with a two-layer Percoll density gradient procedure. Half of each of 25 semen samples were prepared by each technique. The oocytes from each patient were randomly injected, half with spermatozoa prepared by glass wool filtration and half with Percoll-separated spermatozoa from the same semen sample. The percentage of recovered motile spermatozoa, the total motile sperm count, the percentage of morphologically normal forms, the fertilization rate, the cleavage rate and embryo quality obtained with both preparations were analysed. The 95% confidence intervals obtained through the Altman-Bland analysis showed that the percentage of motile spermatozoa recovered was 3.5-9.9% higher with the glass wool filtration technique, and this was highly correlated (r = 0.92, P = 0.0001) to the method. Similarly, the total number of spermatozoa available for ICSI was 0.18 x 10(6)-2.44 x 10(6) higher with the glass wool column and was highly correlated to the method (r = 0.956, P = 0.0001). Also, the percentage of normal forms was 1.25-3.31% higher after glass wool filtration but was poorly correlated to the method (r = 0.47, P = 0.017). Out of 100 metaphase II oocytes injected with glass wool-extracted spermatozoa, 77 fertilized and 72 cleaved. Out of 97 metaphase II oocytes injected with Percoll-selected spermatozoa, 71 fertilized and 69 cleaved. These results were not statistically different. The mean +/- SEM embryo quality score for the glass wool group (2.90 +/- 0.27) was the same as that for the Percoll group (2.80 +/- 0.24). No fertilization failures occurred and 11 patients (44% per oocyte retrieval) became pregnant. It was concluded that glass wool filtration for semen preparation in an ICSI programme offers higher sperm recovery and sperm morphology of superior quality than with the classic two-layer Percoll gradient method, without affecting the fertilization rate and embryo quality.

Is intracytoplasmic sperm injection (ICSI) a safe procedure? What do we learn from early pregnancy data about ICSI?

The aim of this study was to evaluate the safety of the intracytoplasmic sperm injection (ICSI) procedure by analysing early pregnancy data from ICSI and in-vitro fertilization (IVF) patients. In all, 50 ICSI pregnancies were compared with 226 IVF pregnancies. Comparisons were made during the first 9 weeks after the theoretical last menstrual period (7 weeks after oocyte retrieval) with regard to epidemiological data, plasma hormonal concentrations and transvaginal ultrasonographical findings. Although patients were significantly (P < 0.001) younger in ICSI (31 years) than in IVF pregnancies (33 years), their duration of infertility was similar. Miscarriage and multiple gestation rates were not significantly different in ICSI pregnancies (respectively 24 and 24%) from those found after IVF (32 and 29%). The probability of developmental arrest of the intrauterine sac (miscarriages and vanishing twins) was similar in both ICSI (16%) and IVF (25%) cases. The mean plasma hormonal concentrations starting from day 11 after oocyte retrieval were similar in both groups. Every ICSI and IVF pregnancy showed an embryo with cardiac activity at 7 weeks. Early pregnancy data did not show any abnormal findings for pregnancies achieved using ICSI compared to those achieved by IVF.

Alternative splicing within and between alleles of the ATPase gene 1 locus of Trypanosoma brucei

The P-type ATPase gene TBA1 of Trypanosoma brucei belongs to a polycistronic transcription unit. We analyzed the structure and expression of a 4-kb region located immediately downstream from TBA1. This region is unique and contains two large open reading frames transcribed into stable mRNAs. These putative genes, termed ADG1 and ADG2, can respectively encode a 24-kDa and a 81-kDa protein. The intergenic spacings between the polyadenylation sites and the next 3' splice acceptor sites are very short: 148 bp between TBA1 and ADG1, and 127 bp between ADG1 and ADG2. Transcripts from each of the two ADG1 alleles can be detected, indicating that both homologs are transcribed. These transcripts are differentially spliced due to a single base difference which destroys in one homolog the AG acceptor site present in the other. In the 'mutant' allele an alternative downstream splice acceptor site is used. Despite its sequence conservation in both alleles, this splice site is only used in the allele lacking the upstream AG acceptor site. The major population of ADG1 transcripts exhibit a long 5'-untranslated extension and no 3'-terminal tail, but a minor population shows a smaller 5'-untranslated region due alternative splicing closer to the initiation codon of the gene. The steady-state amounts of transcripts from individual genes in this region are differentially stage-regulated.

Structure and transcription of a P-ATPase gene from Trypanosoma brucei

A putative ATPase gene was cloned from Trypanosoma brucei genomic DNA. The length of the gene open reading frame is 3,033 bp, predicting a protein of about 110 kDa. The sequence of this protein shares 10 blocks of homology with other eukaryotic ATPases, including the putative phosphorylation site characteristic of P-ATPases. Its hydropathy profile reveals 8-10 potential membrane-spanning regions. While the amino acid sequence of the T. brucei ATPase shows only 25% overall homology with its counterpart from the related kinetoplastid protozoan Leishmania donovani, 49% sequence conservation is found when compared with the calcium-ATPase from rabbit sarcoplasmic reticulum. This gene is present in only one copy, localized in the large chromosome fraction. It is transcribed at a similar level in procyclic and bloodstream forms, as a 4.3-kb mRNA. Run-on assays suggest continuous transcription of the gene and flanking sequences over at least 10 kb, by a RNA polymerase sensitive to alpha-amanitin. Transcription inhibition by UV irradiation suggests that the ATPase gene is more than 4 kb downstream from its promoter.

A gene from the VSG expression site of Trypanosoma brucei encodes a protein with both leucine-rich repeats and a putative zinc finger

The transcription unit of the gene for the variant specific glycoprotein (VSG) AnTat 1.3A of Trypanosoma brucei contains several associated genes (ESAGs, for Expression Site-Associated Genes), 7 of which have already been described. We report here the characterization of a further ESAG, which we term ESAG 8, present 1 kb downstream from the putative adenylate cyclase gene ESAG 4. ESAG 8 encodes a 70 kd protein whose sequence indicates that it is probably not exposed at the cell surface. With the exception of the N-terminal domain which contains a presumptive DNA-binding zinc finger, the ESAG 8 protein consists exclusively of leucine-rich repeats of 23 amino acids, typical of protein-interacting domains such as the RAS-interacting region of the yeast adenylate cyclase. ESAG 8 transcripts are only found in bloodstream forms, and their level is particularly low, suggesting a high rate of degradation. The ESAG 8 protein may be involved in stage-specific regulatory processes, such as gene expression control or adenylate cyclase activation.

The genes and transcripts of an antigen gene expression site from T. brucei

The AnTat 1.3A antigen gene expression site of T. brucei was cloned from genomic libraries of the 200 kb expressor chromosome. In addition to the antigen gene, it contains seven putative coding regions (ESAGs, for expression site-associated genes), as well as a RIME retroposon. The polypeptide encoded by ESAG 4 shows homology to yeast adenylate cyclase, and possesses structural features of a transmembrane protein. The expression site is transcribed by a pol l-like polymerase in the parasite bloodstream form only, but sequences similar to ESAGs 5, 4, and 2 are also transcribed constitutively elsewhere, by a polymerase sensitive to alpha-amanitin. Ultraviolet irradiation, which seems to block RNA processing, allows the tentative mapping of a transcription promoter about 45 kb upstream of the antigen gene.