Embryo catheter loading and embryo culture techniques: results of a worldwide Web-based survey.

PURPOSE: To identify trends in embryo catheter loading and embryo culture techniques performed worldwide. METHODS: A retrospective evaluation using the results of a web-based survey, (IVF Worldwide ( www.IVF-worldwide.com ), was performed. RESULTS: Responses from 265 centers in 71 countries were obtained. Most centers (97 %) preferred a catheter with its orifice on top, with only 3 % preferring a catheter with the orifice on its side; 41 % preferred a catheter marked for clear ultrasound view. The most commonly-reported methods of embryo loading were medium-air-embryo-air-medium (42 %), medium in catheter with embryo at end (20 %) and medium-air-embryo (15 %). In 68 % of centers the final volume of the catheter was up to 0.3 ml, with only 19 % using 0.3-0.5 ml and 1 % using 0.5-0.7 ml. Using reduced oxygen concentrations for embryo culture was divided between those who used it in combination with the two-gas system (34 %) and those who did not use it at all (39 %); 24 % reported using a three-gas system. Most clinics using reduced oxygen concentrations used it throughout the entire culture period. Half of centers (51 %) reported using reduced oxygen concentrations for the entire IVF population while 6 % reserved it only for blastocyst transfer. The use of sequential media was highly dominant with 40 % reporting its use.

At what age can human oocytes be obtained?

OBJECTIVE: To determine whether oocyte retrieval and in vitro maturation (IVM) is effective in girls undergoing fertility preservation before cancer treatment. DESIGN: Cohort study. SETTING: Tertiary university medical center. PATIENT(S): Patients

Should ovarian cryopreservation be offered to girls with cancer.

Current therapy of childhood cancer makes long-term survival a realistic outcome for most patients. However, some treatment regimens entail a significant risk of infertility. No established method for preservation of female fertility is currently available. Ovarian cryopreservation is an experimental technology that is being offered with increasing frequency to women undergoing cancer therapy. It has not yet been reported in children and adolescent girls. The aim of this review is to stimulate discussion on the possibility of performing ovarian cryopreservation in pre-menarcheal girls in advance of therapies that may induce ovarian failure. We present a multi-disciplinary discussion of the risks and benefits associated with the procedure and propose guidelines for its implementation. We propose that all girls about to receive treatment that has a high risk for infertility be offered consultation about the possibility of ovarian cryopreservation.

Sibling oocyte submission to IVF and ICSI in unexplained infertility patients: a potential assay for gamete quality.

In order to reduce total fertilization failure in unexplained infertility, sibling oocytes were submitted to both conventional IVF and intracytoplasmic sperm injection (ICSI). Two groups of ICSI embryos were compared in unexplained infertility patients: those derived from ICSI when IVF had failed to fertilize, and those derived from ICSI while their sibling oocytes were fertilized by IVF. The outcome of oocytes fertilized exclusively by ICSI (essential ICSI, n = 749) was compared with those fertilized both by IVF and ICSI (non-essential ICSI, n = 957) in all IVF patients treated for unexplained infertility at the Hadassah Hospital (1999-2002). The latter group was further subdivided into ICSI and IVF embryos. Total fertilization rate was 54%. Fertilization rates by ICSI were lower in the essential ICSI compared with the non-essential ICSI group, at 65 and 73% (P < 0.025). Pregnancy rates per embryo transfer in the essential ICSI group (49%), ICSI derived embryos group (55%) and IVF derived embryos (44%) from the non-essential ICSI group, were similar. Implantation rates were lower in the essential ICSI group as compared with the non-essential ICSI group (21 versus 32% respectively; P < 0.05) and 26% for IVF embryos. In conclusion, essential ICSI was associated with lower fertilization and implantation rates.

Mouse embryos generated from frozen-thawed oocytes can successfully survive a second cryopreservation.

BACKGROUND: To determine whether mouse embryos generated from frozen-thawed oocytes can successfully survive a second cryopreservation. METHODS: Immature C57BL6*BALB/c female mice underwent superovulation and the collected oocytes were divided into three groups. Group A oocytes (n = 107) underwent IVF. Group B oocytes (n = 167) underwent IVF and embryos generated were then cryopreserved. Group C oocytes (n = 94) were cryopreserved, thawed and underwent IVF. Two-four-cell stage embryos were re-cryopreserved and thawed. Embryos from all groups were then cultured to the blastocyst stage. RESULTS: Cleavage rates to the 2-4-cell stage were 78, 71 and 46% for groups A, B and C respectively. Blastulation rates from 2-4 cell-stage embryos were 37/83 (45%), 27/118 (23%) and 8/35 (23%) for groups A, B and C respectively. Development to blastocysts was observed in 37/107 oocytes (35%), 27/167 oocytes (16%) and only 8/94 oocytes (9%) for groups A, B and C respectively. CONCLUSION: Oocyte cryopreservation results in reduced fertilization rates. Embryo cryopreservation reduces blastulation rates by half regardless of whether the oocytes were fertilized fresh or frozen-thawed. Nevertheless, embryos generated from cryopreserved oocytes can survive cryopreservation and develop to the blastocyst stage at rates comparable with embryos obtained from fresh oocytes.

Hyaluronic acid can successfully replace albumin as the sole macromolecule in a human embryo transfer medium.

OBJECTIVE: To examine the effect on pregnancy and implantation rates when highly purified, fermentation-based hyaluronic acid was the only macromolecule supplement to the transfer medium in a human IVF program. DESIGN: Prospective randomized study. SETTING: In vitro fertilization center in an academic medical institution. PATIENT(S): Eighty patients were included in this prospective randomized double blind study. Inclusion criteria were age