André Van Steirteghem

POU5F1 Isoforms Show Different Expression Patterns in Human Embryonic Stem Cells and Preimplantation Embryos

The contribution of the POU domain, class 5, transcription factor‐1 (POU5F1) in maintaining totipotency in human embryonic stem cells (hESCs) has been repeatedly proven. In humans, two isoforms are encoded: POU5F1_iA and POU5F1_iB. So far, no discrimination has been made between the isoforms in POU5F1 studies, and it is unknown which isoform contributes to the undifferentiated phenotype. Using immunocytochemistry, expression of POU5F1_iA and POU5F1_iB was examined in hESCs and all stages of human preimplantation development to look for differences in expression, biological activity, and relation to totipotency. POU5F1_iA and POU5F1_iB displayed different temporal and spatial expression patterns. During human preimplantation development, a significant POU5F1_iA expression was seen in all nuclei of compacted embryos and blastocysts and a clear POU5F1_iB expression was detected from the four‐cell stage onwards in the cytoplasm of all cells. The cytoplasmic localization might imply no or other biological functions beyond transcription activation for POU5F1_iB. The stemness properties of POU5F1 can be assigned to POU5F1_iA because hESCs expressed POU5F1_iA but not POU5F1_iB. However, POU5F1_iA is not the appropriate marker to identify totipotent cells, because POU5F1_iA was also expressed in the nontotipotent trophectoderm and was not expressed in zygotes and early cleavage stage embryos, which are assumed to be totipotent. The expression pattern of POU5F1_iA may suggest that POU5F1_iA alone cannot sustain totipotency and that coexpression with other stemness factors might be the key to totipotency.

Rescue IVF and coasting with the use of a GnRH antagonist after ovulation induction

The major risks of exogenous gonadotrophin therapy for ovulation induction in a patient with polycystic ovaries (PCO) are multiple pregnancies and ovarian hyperstimulation syndrome (OHSS). This case report describes a 23-year-old patient, who was referred to the Centre for Reproductive Medicine in Brussels because of a high risk of developing OHSS and rising LH following ovulation induction with a low-dose step-up protocol using gonadotrophins. After counselling the patient, the decision was made to perform a rescue IVF cycle. The patient was first coasted with 0.25 mg ganirelix; the serum oestradiol concentrations decreased and the LH peak was successfully suppressed. No OHSS occurred. An ongoing twin pregnancy was achieved after the transfer of two embryos. This case report demonstrates the feasibility of coasting with LH-releasing hormone (LHRH) antagonists (0.25 mg ganirelix) and the usefulness of the antagonists for ovulation induction cycles in patients who need rescue IVF.

The impact of LH serum concentration on the clinical outcome of IVF cycles in patients receiving two regimens of clomiphene citrate/gonadotrophin/0.25 mg cetrorelix

Clomiphene citrate treatment with the association of gonadotrophins and the GnRH antagonist cetrorelix 0.25mg was analysed in two different stimulation protocols for IVF. In protocol I, 18 patients were sequentially stimulated with clomiphene citrate and gonadotrophins. In protocol II, 28 patients started the gonadotrophin injections during the clomiphene citrate administration. LH values significantly dropped after the first 0.25 mg cetrorelix injection in both protocols. A total of 22% and 7% of cycles were cancelled in protocols I and II, respectively, because of poor follicular development. The clinical pregnancy rate following embryo transfer was 18.1% in protocol I and 29.1% in protocol II. In two (11.1%) cycles stimulated according to protocol I and in eight (28.5%) cycles from protocol II, premature LH surges occurred. In patients with premature LH surge, significantly fewer metaphase II oocytes were obtained. The clinical pregnancy rate following embryo transfer was 12.5% in patients with surge compared with 29.6% in patients without. LH values were lower before HCG injection in patients who achieved pregnancy in the study cycle. In conclusion, sequential clomiphene citrate and gonadotrophin administration is not recommended for clomiphene citrate/gonadotrophin/cetrorelix 0.25 cycles. Cetrorelix 0.25 mg/day was associated with a high incidence of premature LH surges and premature LH surges were associated with an adverse cycle outcome.

Genetic Problems and Congenital Malformations in 1987 ICSI Children

When assisted fertilization and intracytoplasmic sperm injection (ICSI) were introduced, there was major concern about the safety of the newly introduced technique. Intracytoplasmic sperm injection is indeed a more invasive procedure than routine IVF because one spermatozoon is injected through the oo-cyte membrane and because fertilization can be obtained from sperm that could never have been used before in fertility treatment. Even more questions arose and concern was again expressed when ICSI with nonejaculated spermatozoa, either epidididymal or testicular, was introduced. Emphasis was put on the fact that because more chromosomal aberrations are found in azoospermic males and more in particular in case of nonobstructive azoosper-mia, the risk for chromosomal aberrations in the offspring might even be higher. Other heritable genetic causes might also be involved. On the other hand, it was suspected that imprinting may be less complete at the time of fertilization if testicular sperm is used. If this were so, then it would be unlikely to impair fertilization and early development, but anomalies might become manifest at birth or only later in life.