W.B. Schoolcraft

Blastocyst score affects implantation and pregnancy outcome: towards a single blastocyst transfer.

OBJECTIVE To determine the relationship between blastocyst score and pregnancy outcome. DESIGN Retrospective review of blastocyst transfer in an IVF clinic. SETTING Private assisted reproductive technology unit. PATIENT(S) 107 patients undergoing blastocyst culture and transfer of two embryos. INTERVENTION(S) Culture of all pronucleate embryos in sequential media to the blastocyst stage (day 5), followed by transfer of two blastocysts. MAIN OUTCOME MEASURE(S) Implantation rates, pregnancy rates, and twinning were analyzed. RESULT(S) When a patient received two top-scoring blastocysts (64% of patients), implantation and pregnancy rates were 70% and 87%, respectively. The twinning rate in this group was 61%. When only one top-quality blastocyst was available for transfer (21% of patients), the implantation and pregnancy rates were 50% and 70%. The twinning rate for this group was 50%. In contrast, when only low-scoring blastocysts were available for transfer (15% of patients), implantation and pregnancy rates were 28% and 44%, and the twinning rate was 29%. No monozygotic twins were observed in this group of patients. CONCLUSION(S) The ability to transfer one high-scoring blastocyst should lead to pregnancy rates greater than 60%, without the complication of twins.

A prospective randomized trial of blastocyst culture and transfer in in-vitro fertilization.

The effectiveness of blastocyst culture and transfer in human in-vitro fertilization (IVF) was evaluated in a prospective randomized trial in patients having a moderate to good response to gonadotrophin stimulation. Embryos were transferred either on day 3 after culture to around the 8-cell stage in Hams F-10 medium supplemented with fetal cord serum, or on day 5 after culture to the blastocyst stage in the sequential serum-free media G 1.2 and G 2.2. The pregnancy rates after transfer on day 3 or day 5 were equivalent, 66 and 71% respectively; however, significantly more embryos were transferred on day 3 (3.7) than on day 5 (2.2). The number of blastocysts transferred did not affect the implantation rate, and pregnancy rates when either two or three blastocysts were transferred were 68 and 87% respectively. The implantation rate of the blastocysts (50.5% fetal heart beat) was significantly higher compared to the cleavage stage embryos transferred on day 3 (30.1%). The percentage of blastocyst development was not affected by the number of 2-pronuclear embryos, or by maternal age. Irrespective of the number of blastocysts formed, pregnancy rates were similar. Furthermore, the pregnancy rate following blastocyst transfer in patients with 10 or more follicles at the time of human chorionic gonadotrophin administration was not affected by patient age. More than 60% of patients having blastocyst culture and transfer had supernumerary embryos for cryopreservation. The establishment of a pregnancy following thaw and transfer confirmed the viability of cryopreserved blastocysts cultured in the absence of serum or co-culture. The ability to transfer just two blastocysts while maintaining high pregnancy rates will therefore help to eliminate high order multiple gestations and improve the overall efficiency of human IVF.

Culture and transfer of human blastocysts increases implantation rates and reduces the need for multiple embryo transfers

OBJECTIVE To determine whether the transfer of blastocysts on day 5, developed in sequential culture media, resulted in an increase in implantation rate compared with embryos transferred on day 3. DESIGN Comparative study of embryo culture regimes. SETTING Private practice assisted reproductive technology center. PATIENT(S) Twenty-three patients undergoing routine IVF cycles. INTERVENTION(S) Culture of embryos to day 3 in either standard culture conditions or a serum-free chemically defined medium. One hundred one embryos were subsequently cultured from day 3 to day 5 in a second serum-free medium specifically designed to support development of the blastocyst. MAIN OUTCOME MEASURE(S) Embryo cell number and quality on day 3. Blastocyst development on day 5. Implantation rate (determined by fetal heart) and ongoing pregnancy rate (PR). RESULT(S) Implantation rates for embryos transferred at the blastocyst stage of development were twice that observed for embryos transferred on day 3, around the eight-cell stage. Significantly more embryos were required for transfer on day 3, compared with day 5, to establish similar PRs. CONCLUSION(S) Viable human blastocysts can be obtained in sequential culture media in the absence of coculture and serum. Transfer of blastocysts in IVF will facilitate high PRs while limiting the number of embryos transferred and therefore minimizes the risk of multiple gestation.

Vitrification of mouse and human blastocysts using a novel cryoloop container-less technique.

OBJECTIVE To vitrify mouse and human blastocysts with use of the cryoloop procedure and to assess subsequent development. DESIGN Controlled study of vitrification of mouse and human blastocysts. SETTING Research department of a private assisted reproductive technology unit. PATIENT(S) Blastocysts that were not suitable to be frozen were donated from patients. INTERVENTION(S) Culture of pronucleate embryos in sequential media to the blastocyst stage. MAIN OUTCOME MEASURE(S) Survival of the vitrification procedure was assessed by reexpansion, hatching, and outgrowth in culture. In addition, the viability of mouse blastocysts was assessed after transfer to pseudopregnant recipients. RESULT(S) Vitrification of mouse blastocysts did not affect the ability to reexpand, hatch, or outgrow in culture. Furthermore, implantation rates and fetal development were equivalent for nonfrozen and vitrified blastocysts. Vitrified human blastocysts were able to hatch and outgrow in culture at rates similar to nonfrozen controls. CONCLUSION(S) Cryoloop vitrification was able to cryopreserve mouse and human blastocysts without any reduction in the ability to reexpand and hatch in culture. Furthermore, viability was not reduced by the cryoloop vitrification of mouse blastocysts.

Clinical application of comprehensive chromosomal screening at the blastocyst stage

OBJECTIVE To evaluate a new strategy for comprehensive chromosome screening at the blastocyst stage. DESIGN Clinical research study. SETTING An IVF clinic and a specialist preimplantation genetic diagnosis laboratory. PATIENT(S) Forty-five infertile couples participated in the study. The mean maternal age was 37.7 years, and most couples had at least one previous unsuccessful IVF treatment cycle (mean 2.4). INTERVENTION(S) This study used a novel chromosome screening approach, combining biopsy of several trophectoderm cells on day 5 after fertilization and detailed analysis of all 24 types of chromosome using comparative genomic hybridization. MAIN OUTCOME MEASURE(S) Proportion of embryos yielding a diagnostic result, aneuploidy rate, implantation rate, and pregnancy rate. RESULT(S) A diagnosis was obtained from 93.7% of embryos tested. The aneuploidy rate was 51.3%. The probability of an individual transferred embryo forming a pregnancy reaching the third trimester/birth was 68.9%, an implantation rate 50% higher than contemporary cycles from the same clinic. The pregnancy rate was 82.2%. CONCLUSION(S) The comprehensive chromosome screening method described overcomes many of the problems that limited earlier aneuploidy screening techniques and may finally allow preimplantation genetic screening to achieve the benefits predicted by theory. The high embryo implantation rate achieved is particularly encouraging and, if confirmed in subsequent studies, will be of great significance for IVF clinics attempting to reduce the number of embryos transferred or to implement single embryo transfer.

Evaluating strategies for improving ovarian response of the poor responder undergoing assisted reproductive techniques

OBJECTIVE To assess the efficacy of various controlled ovarian hyperstimulation (COH) regimens in the prior poor-responder patient preparing for assisted reproductive techniques. DESIGN English-language literature review. PATIENT(S) Candidates for assisted reproductive techniques who had been defined as having a prior suboptimal response to standard COH regimens. INTERVENTION(S) A variety of regimes are reviewed, including increased gonadotropin doses, change of gonadotropins, adjunctive growth hormone (GH), luteal phase (long) GnRH agonist (GnRH-a) initiation, early follicular phase (flare) GnRH-a initiation, low-dose luteal phase (ultrashort) GnRH-a initiation, progestin pretreatment, and microdose flare GnRH-a initiation. MAIN OUTCOME MEASURE(S) Maximal serum E(2) levels, follicular development, dose, and duration of gonadotropin therapy, cycle cancellation rates, oocytes retrieved, embryos transferred, and clinical and ongoing pregnancy rates. RESULT(S) A lack of uniformity in definition of the poor responder and of prospective randomized trials make data interpretation somewhat difficult. Of the varied strategies proposed, those that seem to be more uniformly beneficial are microdose GnRH-a flare and late luteal phase initiation of a short course of low-dose GnRH-a discontinued before COH. CONCLUSION(S) No single regimen will benefit all poor responders. General acceptance of uniform definitions and performance of large-scale prospective randomized trials are critical. Development of a reliable precycle screen will allow effective differentiation among normal responders, poor responders, and those who will not conceive with their own oocytes.

Noninvasive assessment of human embryo nutrient consumption as a measure of developmental potential

OBJECTIVE To determine the relationship between blastocyst development and morphology and embryo metabolism. DESIGN Noninvasive assessment of carbohydrate uptake and ammonium production by individual embryos. SETTING Private assisted reproductive technology unit. PATIENT(S) Patients donated, with consent, cryopreserved pronucleate embryos and noncryopreserved blastocysts. INTERVENTION(S) Culture of 60 thawed pronucleate embryos in sequential media to the blastocyst stage with concomitant noninvasive analysis of embryo metabolism and analysis of 13 blastocysts from noncryopreserved embryos. MAIN OUTCOME MEASURE(S) Pyruvate and glucose consumption as well as blastocyst formation and quality. RESULT(S) Pyruvate and glucose uptakes on day 4 were significantly higher by embryos that went on to form blastocysts than by embryos that failed to develop to the blastocyst stage. Glucose uptakes were greatest in those blastocysts of highest grade, whereas pyruvate uptakes were similar irrespective of blastocyst grade, indicating that glucose is the more important nutrient for the human blastocyst. Among blastocysts of the same grade from the same patient, there was considerable spread of glucose consumption, indicating that glucose consumption may be of use in identifying blastocysts for transfer. Ammonium production by individual embryos was also measured, reflecting amino acid transamination and use by the human embryo. CONCLUSION(S) The ability to identify in culture the embryo with the highest developmental potential will facilitate the move to single-embryo transfers.

Efficacy and safety of ganirelix acetate versus leuprolide acetate in women undergoing controlled ovarian hyperstimulation.

OBJECTIVE To assess the efficacy, safety, and local tolerance of ganirelix acetate for the inhibition of premature luteinizing hormone (LH) surges in women undergoing controlled ovarian hyperstimulation (COH). DESIGN Phase III, multicenter, open-label randomized trial. SETTING In vitro fertilization (IVF) centers in North America. PATIENT(S) Healthy female partners (n = 313) in subfertile couples for whom COH and IVF or intracytoplasmic sperm injection were indicated. INTERVENTION(S) Patients were randomized to receive one COH cycle with ganirelix or the reference treatment, a long protocol of leuprolide acetate in conjunction with follitropin-beta for injection. OUTCOME MEASURE(S) Number of oocytes retrieved, pregnancy rates, endocrine variables, and safety variables. RESULT(S) The mean number of oocytes retrieved per attempt was 11.6 in the ganirelix group and 14.1 in the leuprolide group. Fertilization rates were 62.4% and 61.9% in the ganirelix and leuprolide groups, respectively, and implantation rates were 21.1% and 26.1%. Clinical and ongoing pregnancy rates per attempt were 35.4% and 30.8% in the ganirelix group and 38.4% and 36.4% in the leuprolide acetate group. Fewer moderate and severe injection site reactions were reported with ganirelix (11.9% and 0.6%) than with leuprolide (24.4% and 1.1%). CONCLUSION(S) Ganirelix is effective, safe, and well tolerated. Compared with leuprolide acetate, ganirelix therapy has a shorter duration and fewer injections but produces a similar pregnancy rate.

LOWER PREGNANCY RATE WITH PREMATURE LUTEINIZATION DURING PITUITARY SUPPRESSION WITH LEUPROLIDE ACETATE

The relationship of the circulating level of progesterone (P) on the day of human chorionic gonadotropin (hCG) injection to occurrence of clinical pregnancy was examined in 133 leuprolide acetate human menopausal gonadotropin (hMG) in vitro fertilization cycles in women having at least three embryos transferred. Progesterone concentrations greater than 0.5 ng/mL were associated with a significantly lower rate of pregnancy (12/59, 20%) compared with less than 0.5 ng/mL (40/74, 54%, P less than 0.005). The higher P cycles were associated with greater patient age and hMG dose, although these relationships appeared to be indirect. Luteinizing hormone (LH) concentrations remained suppressed. Ovarian stimulation may cause excessive luteinization and an adverse cycle outcome even in the presence of low LH levels. Prospective use of P levels may be helpful to determine optimal hCG timing.

Blastocyst culture and transfer: analysis of results and parameters affecting outcome in two in vitro fertilization programs

OBJECTIVE To determine whether previously described advanced blastocyst development and high implantation rates are confirmed in an expanded multicenter trial. DESIGN Retrospective review. SETTING Two private assisted reproductive technology units. PATIENT(S) One hundred seventy-four patients who underwent blastocyst culture and transfer. INTERVENTION(S) Culture of all pronucleate embryos in sequential media to the blastocyst stage (day 5) followed by ET. MAIN OUTCOME MEASURE(S) The number and percentage of blastocysts developed, implantation rates, pregnancy rates, and parameters that affected outcome were analyzed. RESULT(S) Only 3 of 174 patients failed to achieve blastocyst-stage ET. The mean blastocyst development rate was 48%. The ongoing pregnancy rate was 66.3% per oocyte retrieval, with a mean (+/-SE) of 2.2 +/- 0.05 blastocysts transferred and an implantation rate of 48% per blastocyst transferred. CONCLUSION(S) Blastocyst culture and transfer is an effective means of treating patients who respond well to gonadotropins. High pregnancy rates can be accomplished with low numbers of embryos transferred. Patients who failed to achieve ET were rare.