High responders are not exempt from detrimental effects of prematurely rising progesterone levels in fresh embryo transfer cycles.

RESEARCH QUESTION: Are high-responder IVF patients protected from the deleterious effect of prematurely elevated serum progesterone level on the probability of pregnancy? DESIGN: In this retrospective cohort study, 2971 autologous fresh embryo transfer IVF cycles with gonadotrophin-releasing hormone agonist long protocol were analysed to investigate whether the detrimental effect of prematurely rising progesterone levels on clinical pregnancy rate (CPR) varies depending on the magnitude of ovarian response. Nine different evenly spaced intervals were constructed for serum progesterone level on the human chorionic gonadotrophin day (<0.5/0.5-0.9/1-1.4/1.5-1.9/2-2.4/2.5-2.9/3-3.4/3.5-3.9/>4 ng/ml). Then, IVF cycles in each of these intervals were further divided into low (≤3 oocytes), normal (4-15 oocytes) and high responders (≥16 oocytes). RESULTS: The progressive rise of serum progesterone from the <0.5 to the >4 ng/ml interval caused a gradual and continuous decline in the CPR of all three types of ovarian response. The absolute difference in the CPR between the lowest and the highest progesterone groups was not related to the magnitude of ovarian response (-26.6%, -37.7% and -40.7% for the low, normal and high responders, respectively). On multivariate logistic regression analysis, the detrimental effect of progesterone started at 1.5-1.9 ng/ml, 3.0-3.4 ng/ml and 4.0-4.4 ng/ml intervals for the low, normal and high responders, respectively. CONCLUSION: High responders are not exempt from the detrimental effects of prematurely rising serum progesterone levels but the threshold interval where the detrimental effect begins is higher in the high responders compared with the low and normal responders.

Clinical outcome of intracytoplasmic injection of spermatozoa morphologically selected under high magnification: a prospective randomized study.

Recent evidence shows that the selection of spermatozoa based on the analysis of morphology under high magnification (×6000) may have a positive impact on embryo development in cases with severe male factor infertility and/or previous implantation failures. The objective of this prospective randomized study was to compare the clinical outcome of 87 intracytoplasmic morphologically selected sperm injection (IMSI) cycles with 81 conventional intracytoplasmic sperm injection (ICSI) cycles in an unselected infertile population. IMSI did not provide a significant improvement in the clinical outcome compared with ICSI although there were trends for higher implantation (28.9% versus 19.5%), clinical pregnancy (54.0% versus 44.4%) and live birth rates (43.7% versus 38.3%) in the IMSI group. However, severe male factor patients benefited from the IMSI procedure as shown by significantly higher implantation rates compared with their counterparts in the ICSI group (29.6% versus 15.2%, P=0.01). These results suggest that IMSI may improve IVF success rates in a selected group of patients with male factor infertility. New technological developments enable the real time examination of motile spermatozoa with an inverted light microscope equipped with high-power differential interference contrast optics, enhanced by digital imaging. High magnification (over ×6000) provides the identification of spermatozoa with a normal nucleus and nuclear content. Intracytoplasmic injection of spermatozoa selected according to fine nuclear morphology under high magnification may improve the clinical outcome in cases with severe male factor infertility.

Zona-intact versus zona-free blastocyst transfer: a prospective, randomized study.

OBJECTIVE: To compare the outcome of zona-intact versus zona-free blastocyst transfer. DESIGN: Prospective, randomized study. SETTING: Tertiary care private hospital IVF center. PATIENT(S): A total of 240 patients undergoing blastocyst stage ET (119 zona intact and 121 zona free). INTERVENTION(S): In vitro culture of embryos to the blastocyst stage was followed by random allocation to zona-intact or zona-free transfer. MAIN OUTCOME MEASURE(S): Treatment cycle characteristics, implantation, and pregnancy rates. RESULT(S): Transfer of zona-free blastocysts was associated with a higher implantation rate. Subgroup analysis, however, indicated that better outcome was achieved only in the group that received poor-quality blastocysts. Patients undergoing blastocyst transfer for the first time did not seem to benefit from zona-free blastocyst transfer. CONCLUSION(S): Zona-free blastocyst transfer increases the success of blastocyst-stage transfer in patients with poor-quality blastocysts.

Early cleavage of human embryos to the two-cell stage. A simple, effective indicator of implantation and pregnancy in intracytoplasmic sperm injection.

OBJECTIVE: To evaluate the relationship between embryo cleavage time and implantation and pregnancy rates in women undergoing intracytoplasmic sperm injection (ICSI) for male factor infertility. STUDY DESIGN: A total of 78 patients undergoing their first ICSI cycle were evaluated prospectively. Embryos were assessed for early cleavage to the two-cell stage 27 hours after injection. RESULTS: Early cleavage of at least one embryo was observed in 48 cycles (group I). None of the embryos cleaved early in the remaining 30 cycles (group II). There was no difference regarding mean patient age, duration of ovarian stimulation, number of gonadotropin ampules used, number of oocytes retrieved, fertilization, cleavage rates and embryo quality between the two groups. Implantation and clinical pregnancy rates were significantly higher in group I than II (17.9% and 45.8% vs. 5.1% and 16.7%, respectively; P < .05). Furthermore, progression to the blastocyst stage in excess embryos was significantly higher in group I than II (56.7% vs. 25.0%, P < .05). CONCLUSION: Pregnancy and implantation rates were higher in patients who have early cleaving embryos; absence of early cleavage was associated with a poor outcome.

Effect of hyaluronan-enriched transfer medium on implantation and pregnancy rates after day 3 and day 5 embryo transfers: a prospective randomized study.

OBJECTIVE: To analyze whether the use of a hyaluronan-enriched transfer medium (HETM) increases rates of implantation (IRs) and clinical pregnancy (CPRs), compared with the use of a conventional transfer medium after day 3 and day 5 embryo transfers. DESIGN: Prospective randomized controlled trial. SETTING: An assisted reproduction program in a private tertiary-care hospital in Turkey. PATIENT(S): A total of 1,282 consecutive fresh embryo transfer cycles (825 day 3 and 457 day 5) were randomly allocated into two groups. In 639 women, ET was effected with HETM, and in 643, it was effected with a conventional embryo transfer medium. INTERVENTION(S): Embryo transfer using HETM or conventional embryo transfer medium. MAIN OUTCOME MEASURE(S): Clinical pregnancy rates and IRs were compared with regard to day of embryo transfer, women's age, quality of the transferred embryos, and presence of previous implantation failures. RESULT(S): Overall CPRs and IRs significantly increased with the use of HETM (CPR: 54.6% vs. 48.5%, odds ratio: 1.28, 95% confidence interval: 1.03-1.59; IR: 32% vs. 25%, odds ratio: 1.43, 95% confidence interval: 1.23-1.66, for HETM and control groups, respectively). The number needed to treat (NNT) for one additional pregnancy with routine use of HETM was 17. The beneficial effect was more prominent in women who were >35 years of age (NNT = 7), in women who had previous failed cycles (NNT = 7), and in women who had poor-quality embryos (NNT = 8). CONCLUSION(S): The enrichment of transfer medium with hyaluronan increases CPRs and IRs, both for day 3 and day 5 embryo transfers. The beneficial effect was most evident in women who were >35 years of age, in women who had only poor-quality embryos available for transfer, and in women who had previous implantation failures.

Prospective randomized comparison of Wallace and Labotect embryo transfer catheters.

The aim of this study was to compare the clinical performance of Wallace and Labotect embryo transfer catheters in a single assisted reproduction centre. A total of 260 women undergoing embryo transfer were randomized between Wallace and Labotect catheters. When both catheters failed to negotiate the cervical canal, the transfer was accomplished with a stiff catheter. Intention to treat analysis revealed that Wallace and Labotect embryo transfer catheters yielded statistically similar clinical pregnancy (44.6 versus 34.6%), implantation (23.2 versus 18.9%) and ongoing pregnancy (38.5 versus 27.7%) rates. As treated analysis revealed clinical pregnancy rates of 42.5 versus 35.4%, implantation rates of 22.3 versus 20.6% and ongoing pregnancy rates of 36.8 versus 28.3% with Wallace and Labotect catheters respectively. Catheter change due to unsuccessful negotiation of the internal cervical os was significantly more frequently necessary when embryo transfer was first intended with the Wallace than the Labotect catheter (P < 0.001; 33 and 2% respectively). Although not being statistically significant, the observed differences may be regarded as clinically important and may reach statistical significance in larger trials. More trials are necessary before reaching a definitive conclusion regarding the performance of the Labotect embryo transfer catheter.

Oocyte dysmorphism is not associated with aneuploidy in the developing embryo.

OBJECTIVE: Controlled ovarian hyperstimulation yields numerous oocytes with different morphologic features. The purpose of this study was to assess the effect of oocyte dysmorphism on the development and ploidy status of the derived embryo. DESIGN: Retrospective study. SETTING: Private assisted reproduction unit. PATIENT(S): A retrospective analysis was performed on 616 oocytes and 266 embryos of 65 infertile couples who had undergone preimplantation genetic diagnosis and aneuploidy screening for repeated implantation failures. INTERVENTION(S): Oocytes with normal and abnormal morphology and the derived embryos were compared in terms of fertilization, cleavage, and blastocyst formation rates as well as the ploidy status. RESULT(S): Oocyte dysmorphism did not have an adverse effect on fertilization and cleavage rates and quality of day 3 embryos. Single cytoplasmic and multiple abnormalities of the oocyte significantly decreased the blastocyst formation rate of the cleaving embryo. Oocyte dysmorphism did not have a significant association with embryonic aneuploidy. CONCLUSIONS(S): Oocyte dysmorphism was not associated with a higher risk of aneuploidy in the developing embryo. Cytoplasmic dysmorphism or multiple morphologic abnormalities of the oocyte adversely affects the blastocyst formation potential of the derived embryo.

Utilization of high-security straws for embryo freezing in an in vitro fertilization program: a prospective, randomized study.

OBJECTIVE: To compare the outcome of frozen-thawed ET cycles where embryos had been stored in conventional versus ionomeric resin-based, high-security straws (HSSs). DESIGN: Prospective, randomized study. SETTING: Private assisted-reproduction unit. PATIENT(S): Three hundred and six freeze cycles, and 197 thaw cycles. INTERVENTION(S): Day 3 embryos (n = 1,268) were frozen, and 517 were thawed using HSSs. Alternately, day 3 embryos (n = 1,228) were frozen, and 505 were thawed using conventional straws. MAIN OUTCOME MEASURE(S): Cryosurvival, cleavage and morulae formation rates, and clinical pregnancy, implantation, and multiple pregnancy rates. RESULT(S): Although cycle characteristics did not show any differences, the cryosurvival rate was higher in the HSS group (94.7%) than in the conventional straw group (86%), as was the morulae formation rate (58.7% versus 42.7%). Despite a similar number of embryos being transferred, the clinical pregnancy rate (PR) was higher in the HSS group, but the difference lacked statistical significance (42.5% versus 31.2). Implantation rates (19.4% versus 11.4%) and multiple PRs (41.8% versus 16.6%) were significantly higher in the HSS group than in the conventional straw group. CONCLUSION(S): High-security straws are high effective in human embryo cryopreservation, because they provide higher cryosurvival and implantation rates, as well as a lower risk of cross-contamination compared to conventional straws.

Laser-assisted hatching increases pregnancy and implantation rates in cryopreserved embryos that were allowed to cleave in vitro after thawing: a prospective randomized study.

BACKGROUND: Cryopreservation of embryos may lead to zona hardening that may compromise in vivo hatching and implantation following thawing and transfer. Assisted hatching (AH) has been advocated as a means of assisting the natural hatching process and enhancing implantation. METHODS: The aim of this study was to assess in a prospective randomized manner the effect of laser-assisted hatching (LAH) on implantation as well as clinical and multiple pregnancy rates (the primary outcome) after the transfer of frozen-thawed embryos. All embryos were thawed the day before transfer, and LAH was performed the next day on embryos that cleaved. Control group consisted of embryos that were transferred without AH. RESULTS: The performance of LAH significantly increased implantation (9.9 versus 20.1%, P < 0.01), clinical pregnancy (27.3 versus 40.9, P < 0.05) and multiple pregnancy rates (16 versus 40.3%, P < 0.07). In the LAH group, significantly more excess embryos that were left in culture hatched in vitro. CONCLUSIONS: LAH improves the outcome of frozen-thawed embryo transfer when performed before transfer on embryos that were allowed to cleave.

Outcome of blastocyst transfer according to availability of excess blastocysts suitable for cryopreservation.

The purpose of this study was to assess the outcome of blastocyst transfer in relation to the presence or absence of excess blastocysts available for cryopreservation. The study was designed as a retrospective case series in a tertiary care private hospital. The study group consisted of 450 blastocyst stage embryo transfer cycles. In 139 cycles there were excess freezeable blastocysts (group 1), in 78 cycles there were excess but unfreezeable blastocysts (group 2), and in 233 cycles there were no excess blastocysts (group 3). A mean of three blastocysts was replaced in all groups. Treatment cycle characteristics, implantation and pregnancy rates following fresh and cryopreserved blastocyst transfer were assessed in each group. More embryos reached the blastocyst stage in group 1 and more blastocysts were of good quality. In group 1, clinical pregnancy and implantation rates (71 and 41%) were significantly higher compared with groups 2 (56 and 27%) and 3 (43 and 19%). Embryos that were selected for transfer among a cohort of good quality blastocysts yielded the highest implantation and pregnancy rates. Given a clinical pregnancy rate of 71%, an implantation rate per embryo of 41%, and a multiple pregnancy rate of 58%, serious consideration should be given to a single blastocyst transfer in these patients.

Impact of oocyte pre-incubation time on fertilization, embryo quality and pregnancy rate after intracytoplasmic sperm injection.

Although, it is well known that pre-incubation of oocytes prior to conventional IVF improves fertilization and pregnancy rates, there are conflicting results regarding the effect of pre-incubation time in ICSI. This study evaluated the role of pre-incubation of oocytes on outcome in intracytoplasmic sperm injection (ICSI) cycles. A total of 1260 patients undergoing their first ICSI cycles were evaluated retrospectively. In patients undergoing ICSI during the year 2000 (Group I, n = 670), oocytes were injected immediately after retrieval, whereas in patients undergoing ICSI during 2001 (Group II, n = 590), oocytes were incubated for 2-4 h prior to injection. The mean age of patients was 33.9 +/- 5.04 years and 34.1 +/- 5.06 years in groups I and II, respectively. The number of oocytes with a first polar body (MII) and fertilization and cleavage rates were higher, and embryo quality was significantly better in group II. In contrast, the total numbers of oocytes without a first polar body (MI), those where germinal vesicle breakdown had not occurred (GV), and empty zona oocytes were higher in group I. No difference was found in the number of embryos transferred or implantation or clinical pregnancy rates. This study demonstrated that pre-incubation of oocytes prior to ICSI is associated with improved maturation of oocytes, fertilization and embryo quality.

Pronuclear morphology predicts embryo development and chromosome constitution.

The relationship between pronuclear morphology on the one hand, and embryo development and chromosomal status on the other, was evaluated in 68 couples scheduled to undergo preimplantation genetic diagnosis because of advanced maternal age or recurrent implantation failure. Zygotes were grouped according to their pronuclear (PN) morphology. During the period from fertilization to embryo transfer, cleavage rate, embryo quality, blastocyst formation and results of the chromosomal analysis of 240 embryos were recorded. Both embryo cleavage characteristics and chromosome constitution were related to PN morphology. Embryos developing from zygotes with the normal PN pattern (pattern 0) cleaved faster and formed embryos with better morphology as compared with zygotes with abnormal PN patterns. Aneuploidy rate of embryos derived from zygotes with the normal PN pattern, with a single PN anomaly and with a double PN anomaly was 25.6, 73 and 83% respectively. Chromosomally normal embryos with the normal PN pattern progressed to the blastocyst stage at a higher rate (90%) than chromosomally normal embryos with a single (61%) or a double (40%) PN anomaly. The same relationship applied to chromosomally abnormal embryos. It is concluded that PN morphology predicts both the risk of embryo developmental arrest and that of chromosomal abnormalities.

A comparison of four different techniques of assisted hatching.

BACKGROUND: Assisted hatching (AH) has been proposed as a means to increase the implantation rate in patients with poor prognosis for pregnancy. The procedure appears to be effective when used selectively. Several different methods for AH have been introduced over the years but comparative studies are lacking. The aim of the current study was to compare retrospectively the efficacy of AH performed with four different methods in patients undergoing IVF or ICSI. METHODS: AH was performed prior to day 3 embryo transfer in 794 IVF/ICSI cycles. Indications for AH were females aged >35 years and/or elevated follicular phase FSH levels, previous failed IVF/ICSI cycles, poor embryo quality, and thick zona pellucida (>15 microm). Assignment to one of the four methods of AH was according to the availability of the particular method during the study period. The study was not randomized. RESULTS: Partial zona dissection was used in 239, acid Tyrode in 191, diode laser in 219 and pronase thinning of the zona pellucida in 145. Mean female age, mean number of previous failed IVF/ICSI cycles, number of oocytes retrieved, fertilization and cleavage rates, good quality embryos and zona thickness on day 3 did not differ between groups. Mean number of embryos transferred, implantation rate, clinical pregnancy rate, and abortion rates were likewise similar. CONCLUSIONS: Selective AH using four different methods yields similar implantation and pregnancy rates.

Transfer at the blastocyst stage of embryos derived from testicular round spermatid injection.

BACKGROUND: Intracytoplasmic injection of testicular round spermatids has been suggested as a salvage treatment in couples when testicular sperm extraction does not yield any mature sperm. However, the success of the procedure is debatable, and controversy surrounds issues such as the presence and (if present) identification of spermatids in testicular tissue. Progression rate to the blastocyst stage of spermatid-derived embryos appears to be low. METHODS: In this study, we investigated the feasibility and outcome of blastocyst stage embryo transfer after round spermatid injection (ROSI). ROSI was undertaken in 58 couples who did not yield mature or elongated sperm to testicular sperm extraction. RESULTS: The incidence of blastocyst formation from two pronuclear oocytes was 7.6%. A total of 16 blastocysts were transferred in 12 patients (20.7%). None of the patients conceived. CONCLUSIONS: The results of this study indicate that the blastocyst stage is reached by only very few ROSI-derived embryos and these embryos do not implant.