Donna Dowling-Lacey

Does storage time influence postthaw survival and pregnancy outcome? An analysis of 11,768 cryopreserved human embryos

OBJECTIVE To evaluate the impact of cryopreservation storage duration on embryo survival, implantation competence, and pregnancy outcome. DESIGN Retrospective study. SETTING Academic tertiary-referral infertility center. PATIENT(S) In vitro fertilization patients and recipients of oocyte donation cycles who had cryopreserved embryos and underwent at least one thaw cycle from 1986 to 2007. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Postthaw survival proportion and implantation, clinical pregnancy, miscarriage, and live birth rates. RESULT(S) Length of storage time did not have a significant effect on postthaw survival for IVF or oocyte donation cycles, or for embryos frozen at the pronuclear or cleavage stages. There was no significant impact of the duration of storage on clinical pregnancy, miscarriage, implantation, or live birth rate, whether from IVF or oocyte donation cycles. Logistic regression analysis demonstrated that the length of storage time or developmental stage at freezing were not predictive of embryo survival or pregnancy outcome. Only oocyte age, survival proportion, and number of transferred embryos were positive predictors of pregnancy outcome. CONCLUSION(S) Cryostorage duration did not adversely affect postthaw survival or pregnancy outcome in IVF or oocyte donation patients.

Total quality improvement in the IVF laboratory: choosing indicators of quality

The purpose of this paper is to describe a programme of total quality improvement (TQI) within the IVF laboratory and to provide specific examples of indicators that could be used in such a TQI programme. Although TQI is sometimes confused with quality control (QC) and quality assurance (QA), there are major differences between the three quality plans: (i) QC is an activity designed to ensure that a specific element within the laboratory is functioning correctly; (ii) QA is a comprehensive programme designed to looks at a laboratory as a whole and to identify problems or errors that exist in an attempt to improve the entire process; (iii) TQI is also a comprehensive monitoring process designed not only to detect and eliminate problems, but also to enhance a laboratorys performance by exploring innovation and developing flexibility and effectiveness in all processes. Indicators used in a TQI plan should be objective, relevant to the laboratory, and measure a broad range of specific events or aspects of treatment that reflect the quality of care. Threshold values for each of the indicators should be based on how the specific protocols used in the laboratory impact the outcomes and the nature of the indicators on quality of care.

Impact of male age on the outcome of assisted reproductive technology cycles using donor oocytes

This study assessed the influence of the age of the male partner on the outcome of oocyte donation cycles. A total of 408 couples participating in 519 consecutive anonymous oocyte donation cycles were examined. Main outcome measures were fertilization rate, embryo quality, clinical pregnancy, implantation, miscarriage and live birth rates, as well as the total reproductive potential, which estimates the outcome from fresh and cryopreserved-thawed embryo transfers. A total of 241 cycles resulted in clinical pregnancy (48.5% of transfers). The mean embryo score for transferred embryos (ESTE) was higher in cycles resulting in pregnancy (P=0.003). Semen volume (P<0.001), sperm motility (P<0.001) and fertilization rate (P=0.04) decreased significantly with advanced male age, which did not correlate with mean ESTE or implantation rate. Fertilization rate was the only predictor of ESTE (B=16.066, P=0.012), whereas inseminated/retrieved egg ratio was the only predictor of implantation rate (B=0.555, P=0.039). Pregnancy was only predicted by ESTE (Exp(B)=1.023, P<0.001), which also was the only predictor of live birth (Exp(B)=1.017, P=0.009). There was no predictor of miscarriage (47 cycles, 9.1%) identified. Although semen volume, sperm motility and fertilization rate decreased with advanced male age, embryo quality, clinical pregnancy, implantation, miscarriage and live birth rates were not affected.

Elective transfer of two embryos: Reduction of multiple gestations while maintaining high pregnancy rates

Purpose: To determine if the elective transfer of two embryos reduced the incidence of multiple gestations while maintaining high pregnancy rates. Methods: IVF patients and recipients of oocyte donation with an elective day-3 transfer of 2 or 3 embryos were studied. Result(s): In IVF, the elective transfer of 2 embryos resulted in similar pregnancy rate but significantly reduced the overall incidence of multiple gestations (20% versus 39%) when compared to the elective transfer of 3 embryos. Twin gestations decreased from 28% to 19%, and triplets significantly decreased from 9% to 1%. In oocyte donation, the elective transfer of 2 embryos resulted in similar pregnancy rate but also significantly reduced the overall incidence of multiple gestations (26% versus 48%), with twins decreasing from 34% to 24%, and with a significant reduction of triplets (13% versus 2%). Conclusions: In IVF and oocyte donation, the elective transfer of 2 embryos resulted in similar pregnancy rates and significantly reduced multiple gestation rates when compared to the elective transfer of 3 embryos.

Two singleton live births after the transfer of cryopreserved–thawed day-3 embryos following an unstimulated in-vitro oocyte maturation cycle

The objective was to report two singleton live births after transfer of cryopreserved-thawed day-3 embryos resulting from an unstimulated in-vitro oocyte maturation (IVM) cycle. A 29-year-old female patient with polycystic ovaries (PCO) underwent an unstimulated IVM cycle. A total of 43 prophase-I oocytes were retrieved; 21 oocytes achieved in-vitro maturation to the metaphase-II stage at 36 h post-retrieval and 18 oocytes were fertilized (two pronuclei) after intracytoplasmic sperm injection. Two embryos were transferred in the fresh cycle (no pregnancy) and 15 day-3 embryos (post-oocyte microinjection) were cryopreserved. Subsequently, the patient became pregnant after each of two embryo transfer cycles from cryopreserved-thawed embryos (three and two embryos transferred respectively), with delivery of a single, term, healthy baby after each transfer. It is concluded that healthy live births were documented in a PCO patient undergoing unstimulated IVM followed by transfer of day-3 cryopreserved (slow-freeze)-thawed embryos, adding these methodologies to the armamentarium of assisted reproductive technologies.

PHYSIOLOGY: Evaluation of the Meiotic Spindle Apparatus in Metaphase II Human Oocytes Following Cytoplasmic Donation

Purpose: To determine if the removal of cytoplasm from metaphase II human donor oocytes damages the meiotic spindle apparatus.Materials and Methods: Cryopreservation of metaphase II human oocytes was performed using a fast-freeze, fast-thaw protocol. Upon thaw, oocytes were incubated for 3–4 h and then used for cytoplasmic donation (test oocytes). Oocytes thawed but not used for donation served as controls. Test and control oocytes were fixed using a microtubule-stabilizing buffer. Tubulin was localized using antitubulin monoclonal antibody. Chromosomes were identified by counterstaining with DAPI.Results: Forty-four oocytes had cytoplasm removed (test group) while 12 were not used for the procedure (controls). Twenty-three oocytes survived the donation procedure. Rates of normal spindle structure for the control and test groups were 21/23 (91.3%) and 12/12 (100%), respectively.Conclusion: The removal of cytoplasm from a metaphase II human donor oocyte does not appear to significantly increase the damage to chromosome alignment or to the spindle structure.