Yi-Chi Lin

Relationship of the Human Cumulus-Free Oocyte Maturational Profile with In Vitro Outcome Parameters After Intracytoplasmic Sperm Injection

Purpose:We investigated whether the human oocyte maturational profile at the removal of cumulus/corona cells affects the fertilization rate and subsequent embryo quality after intracytoplasmic sperm injection.Methods:A total of 1011 oocytes from 150 cycles was included in this retrospective analysis. Cumulus-free oocytes that were in prophase or metaphase I of meiosis at the removal of cumulus/corona cells were incubated in vitro until they reached metaphase II (in vitro-matured oocytes) and were then immediately injected with a single spermatozoa. Oocytes that were in metaphase II at the removal of cumulus/corona cells (MII oocytes) received sperm injection after 3–4 hr of preinjection incubation.Results:The fertilization rate of the MII oocytes was significantly higher than that of in vitro-matured oocytes (81 vs 62%; P < 0.001). The cleavage rates were similar in the two groups (MII oocytes, 94%; in vitro-matured oocytes, 91%). However, MII oocytes had significantly higher percentages of good-quality embryos (grade 1–3 embryos, 87 vs 58%, P < 0.001) and embryos with high cumulative embryo scores (score 10–32 embryos, 62 vs 33%, P < 0.001). The mean cumulative embryo score of MII oocytes after fertilization was also higher than that of in vitro-matured oocytes (12.1 ± 3.8 vs 8.8 ± 3.4; P = 0.014).Conclusions:MII oocytes that extruded the first polar body at the removal of cumulus/corona cells had better fertilization rates and embryo morphology than in vitro-matured oocytes that extruded the first polar body following the removal of cumulus/corona cells and in vitro culture.

Human oocyte maturity in vivo determines the outcome of blastocyst development in vitro

AbstractPurpose: To date, the impact of oocyte maturity at aspiration on the blastocyst formation in vitro has not been fully evaluated. This study was undertaken to assess the influence of oocyte maturity in patients undergoing in vitro fertilization and blastocyst transfer program. Methods: A total of 1278 oocytes derived from 147-IVF cycles were retrospectivly analyzed. Oocyte maturity was graded on a scale from 1 to 5 based on the morphology of the ooplasm, cumulus mass, corona radiata, and membrana granulosa cells. Results: Mature oocytes yielded the highest fertilization rates. Although the cleavage rates were similar in both groups, the percentage of poor morphology, day-3 embryos from the nonmature-oocyte group was significantly higher than from the mature-oocyte group (54.7% vs. 15.5%, P < 0.001). Although good morphology, day-3 embryos were collected from nonmature oocytes, the incidence of these embryos developing to the blastocyst stage was significantly less than from mature oocytes (33.3% vs. 71.2%, P < 0.001). Although blastocyst stage embryos were collected from nonmature oocytes, the incidence of these embryos developing to the top-scoring blastocysts was significantly less than from mature oocytes (58.3% vs. 89.5%, P < 0.001). Conclusions: These phenomena suggest that oocyte maturity produced in vivo determine the fertilization potential and subsequent blastocyst quality in vitro.

The Maturity of Human Cumulus-Free Oocytes Is Positively Related to Blastocyst Development and Viability

AbstractPurpose: We investigated whether the human oocyte maturity at the removal of cumulus/corona cells affects the embryo outcome in vitro. Methods: A total of 620 oocytes, which subsequently underwent blastocyst culture, were included in this analysis. Oocytes that were in prophase or Metaphase I of meiosis at the removal of cumulus/corona cells were in Group II. Oocytes that were in Metaphase II at the removal of cumulus/corona cells were in Group I. Results: Group I oocytes yielded the highest fertilization rates (96.3% vs. 77.1%, P < 0.001). The incidence of Group II oocytes developing to the blastocyst stage was significantly less than from Group I oocytes (38.1% vs. 86.1%, P < 0.001). The percentage of top-scoring blastocysts from Group I oocytes was higher than that of Group II oocytes (95.4% vs. 76.2%, P < 0.001). Conclusions: Oocyte maturity at the removal of cumulus/corona cells needs to be considered in selecting good quality blastocysts for embryo transfer.

Progesterone elevation on the day of human chorionic gonadotropin administration is not the only factor determining outcomes of in vitro fertilization

OBJECTIVE To assess whether progesterone elevation is the only factor in determining outcomes of in vitro fertilization (IVF). DESIGN Retrospective cohort study. SETTING Infertility clinic at Kaohsiung Chang Gung Memorial Hospital, Taiwan. PATIENT(S) One thousand five hundred eight women undergoing a total of 1,508 IVF cycles. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Clinical pregnancy and live-birth rates. RESULT(S) Patients were classified into four subgroups according to their progesterone concentration on the day of human chorionic gonadotropin (hCG) triggering. The clinical pregnancy and live-birth rates were statistically significantly associated with the age of the woman, the day of embryo transfer, the progesterone concentration on the day of hCG administration, the number of transferred embryos, and the number of top-quality embryos transferred. However, after omitting the women with the highest progesterone concentration (≥1.94 ng/mL), only four factors-patient age, day of embryo transfer, number of transferred embryos, and number of top-quality embryos transferred-were statistically significantly associated with the clinical pregnancy and live-birth rates. CONCLUSION(S) Progesterone concentration on the day of hCG administration is not the only factor determining the clinical pregnancy and live-birth rates. Fresh embryos from women should be frozen with extremely high progesterone concentrations. Each patients general condition and the capacity for frozen-thawed embryo transfer should be considered before implantation.

Reassessing the feasibility of the zygote score for predicting embryo viability in IVF/ICSI using the GnRH antagonist protocol compared to the long protocol

Background Many factors from the oocyte/sperm or the process of fertilization may affect the zygote formation. The zygote score (Z-score) describes the quality of a human zygote based on its pronuclear morphology, nucleolar precursor bodies, and alignment of polar bodies, and it can be used in the selection process at the zygote stage for embryo transfer or cryopreservation. Objective The aim of this retrospective cohort study was to investigate the relationship between different controlled ovarian stimulation (COS) protocols and the zygote score (Z-score) and to assess the feasibility of the Z-score for predicting embryo survival in the GnRH-antagonist (GnRH-ant) protocol. Methods It is a retrospective, single-center cohort study. A total of 3,826 zygotes with normal fertilization were analyzed from 744 in vitro fertilization /intra-cytoplasmic sperm injection (IVF/ICSI) cycles (long protocol n = 392; GnRH-ant n = 352) between Jan 2010 and April 2014 in the IVF unit of Chang-Gung Memorial Hospital Kaohsiung Medical Center. Results The Z-score distribution differed significantly between these two protocols. The overall Z-score was poorer for zygotes from GnRH-ant cycles (p<0.05). Univariate and multivariate analyses indicated the type of COS protocol is one of the main determinants of Z-score grading. Our study found good-quality day 3 embryo/blastocyst formation and the cumulative embryo survival rate were correlated with the Z-score but not the COS protocol. With the GnRH-ant protocol, the number of Z1 in the transferred cohort embryos was significantly correlated with the clinical pregnancy rate (r = 0.976; p = 0.024) and live birth rate (r = 0.971; p = 0.029). This correlation was not seen with the long protocol. Conclusions The Z-score distribution for the GnRH antagonist cycles was poorer than that of the long protocol, but the Z-score system is a valuable parameter for predicting embryo viability in the GnRH-ant protocol, providing a strong correlation with the clinical pregnancy rate and live birth rate.