Blastocyst transfer: does it really affect the outcome?

Disposition of embryos from women who only produced morphologically poor embryos on day three

Background

The presence of only morphologically poor embryos (MPEs) on day3 is common in autologous in vitro fertilization (IVF), particularly among p Tel: 886-7-7317123 Ext. 8916. Fax: 886-7-7322915.atients who have advanced maternal age or are poor responders. However, there are limited data regarding the disposition of embryos from patients who only produced MPEs on day3. The present study was designed to investigate the possible benefits of extended culturing MPEs. Try to detect whether the extended culture (day4 or day5 culture) can improve the live birth rate per cycle?

Methods

This retrospective, observational, single-center, cohort study examined 224 IVF/intracytoplasmic sperm injection (ICSI) cycles between January 2010 and June 2015, in which women only produced MPEs on day3. A total of 544 MPEs were analyzed. The defines a day3 embryo as an MPE if it fails to develop to eight cells, blastomeres of equal size, and less than 20% cytoplasmic fragments. Of the 224 cycles, 89 (39.7%) underwent fresh embryo transfer on day3, and 135 (60.3%) underwent extended culture. Of the 135 extended cultures, 54 cycles (40.0%) experienced day4, or day5 embryo transfer, 16 cycles (11.9%) had all embryos frozen, and 65 cycles (48.1%) had total embryo arrest.

Results

Analysis of patient baseline demographic data, cycle characteristics, and cycle outcomes for day3 transfer group and extended culture group indicated that a higher body mass index in the day3 transfer group was the only significant difference (p = 0.006). Both fresh transfer groups had low live birth rates (LBRs) (4.5% vs. 7.4% p = 0.46). After extended culture, 65 cycles (48.1%) were cancelled because the embryos exhibited developmental arrest and 70 cycles (51.9%) grew to day4 or day5. Thirteen frozen embryo transfer (FET) cycles and 22 frozen blastocysts derived from MPEs were thawed. There were more high-quality embryos (p < 0.001), higher implantation rates (IRs) (p = 0.038), and higher LBRs (p = 0.042) for embryos that underwent FET cycles. MPES in extended culture transfer have favorable survival than MPES in day3 transfer.

Conclusion

The extended culture of MPEs in fresh transfer cycles did not increase the LBR. However, younger females with the extended culture of MPEs followed by FET resulted in significantly higher LBRs and may be a feasible strategy to improve outcomes for patients with poor embryo quality. However, day3 embryo transfer may be a better choice if a fresh transfer is unrestricted and avoid the cycle cancellation. Extended culture may decrease to the transfer of developmental potential arrest embryos to patients.

Transfer of spontaneously hatching or hatched blastocyst yields better pregnancy rates than expanded blastocyst transfer

CONTEXT:

Blastocyst stage embryo transfer (ET) has become routine practice in recent years. However, probably due to limitations of assisted hatching techniques, expanded blastocyst transfer (EBT) is still the preferred mode. Inexplicably, not much consideration has been given to spontaneously hatching/hatched blastocyst transfer (SHBT).

AIM:

This study aimed to investigate developmental potential of spontaneously hatching/hatched blastocyst against EBT in in vitro fertilization (IVF) cycles.

SETTINGS AND DESIGN:

Prospective study of 146 women undergoing their first IVF- ET cycle.

SUBJECTS AND METHODS:

On the basis of blastocyst status, women were classified into SHBT and EBT groups. Intracytoplasmic sperm injection cycles were excluded to remove male factor bias. Implantation rate (IR), clinical pregnancy rate, and live birth rate were the main outcome measures.

STATISTICAL ANALYSIS:

Graph-pad Prism 5 statistical package.

RESULTS:

SHBT group showed significantly higher blastocyst formation rate (53.3 ± 17.5 vs. 43.1 ± 14.5%, P = 0.0098), top-quality blastocysts (71.8 vs. 53.7%, P = 0.0436), IR (43.6 vs. 27.9%, P = 0.0408), pregnancy rate (59.4 vs. 45.1%, P = 0.0173), and live birth rate (36.8 vs. 22.8%, P = 0.003) compared to EBT group. Multiple pregnancy rates remained comparable between the two groups. Implantation correlated strongly with top-quality blastocysts (Pearson, r = 0.4441) in SHBT group, while the correlation was nonsignificant in EBT group.

CONCLUSION:

Extending culture of expanded blastocysts by a few hours to allow transfer of spontaneously hatching/hatched blastocysts gives higher implantation and pregnancy rates with no added risk of multiple gestations. Spontaneously hatching/hatched blastocysts have a better potential to implant and develop into a positive pregnancy.

Blastocyst culture and transfer: lessons from an unselected, difficult IVF population

Blastocyst-stage transfer has yielded excellent results in good prognosis IVF patients, but its efficacy in the general IVF population has not been clearly demonstrated. The objective of this study was to compare cleavage-stage and blastocyst-stage transfer in a mixed, general IVF population. In a prospective, quasi-randomized study, 152 patients underwent 164 treatment cycles. Patients were allocated to cleavage-stage (group 1; n = 94) or blastocyst-stage (group 2; n = 70) transfer. Main outcome measures included implantation, clinical pregnancy and live birth rates. Implantation (11.2% versus 15.5%), clinical pregnancy (34% versus 21%) and live birth rates per transfer (21.3% versus 13.8%) and per started cycle (21.3% versus 11.4%) were all comparable for groups 1 and 2, respectively. Logistic regression analysis revealed that blastocyst culture and transfer reduced the odds for pregnancy in the general IVF population and defined a good prognosis group for blastocyst transfer. Introducing blastocyst culture and transfer to all IVF patients is not advantageous. Blastocyst transfer should be offered primarily to good prognosis patients, and this group should be specifically defined in each clinical set-up.

Zona-free versus laser zona-assisted hatching blastocyst transfer: a comparison of outcomes

In unselected IVF patients, zona-free and laser zona-assisted hatching produced a comparable effect on blastocyst transfer.

Extended embryo culture to increase implantation rate

Multiple pregnancies are a serious adverse event of IVF treatment. Several strategies have been developed to improve embryo selection and embryo developmental potential to increase pregnancy rates without increasing the risk of multiple pregnancies. The only way to effectively solve this problem is to reduce the number of embryos transferred to one. The introduction of extended embryo culture has provided IVF programmes with a valuable tool to select more accurately those embryos with a higher implantation potential. The concept of single embryo transfer presents a clinical dilemma with seemingly opposing sides: one seeking to maintain acceptable pregnancy rates and the other seeking to reduce the number of twin births or high order multiple pregnancies. The present review addresses the potential benefits and drawbacks of blastocyst transfer.

Prevention of multiple pregnancy following IVF in Spain

Since the development of assisted reproduction techniques most countries have witnessed increased rates of multiple pregnancy. Despite the guidelines proposed by various scientific societies these rates continue to be abnormally high. In Spain, as in other Mediterranean countries, a greater number of embryos are transferred than in northern and central European countries and the incidence of multiple pregnancies is greater in comparison. Effective strategies must be established to prevent multiple pregnancy without reducing overall pregnancy rates. In the authors' institute, taking into account the authors' experience, the relevant literature, and despite the limitation of retrospective studies, it is recommended that a maximum of two embryos are transferred in young women with good quality embryos at the time of transfer. The transfer of three embryos is only recommended in women >or=38 years who have one or no good quality embryos available at the time of transfer. The responsibility for preventing multiple pregnancy lies with health professionals, who must be aware of the risks involved in twin and triplet pregnancy. Couples must be provided with objective information before starting an IVF cycle. Professional societies should highlight the problem and make suitable recommendations.

Vitrification demonstrates significant improvement versus slow freezing of human blastocysts

Blastocyst culture has reduced the number of embryos transferred per cycle, whilst simultaneously creating new quandaries regarding supernumerary blastocyst cryopreservation. This retrospective study was undertaken to compare a slow freezing protocol to a vitrification protocol for cryopreservation of day 5 and day 6 human blastocysts. To demonstrate this, the survival, implantation rate and pregnancy rates were compared after thawing, assessment and embryo transfer of 86 consecutive day 5 and day 6 thawed blastocyst transfer cycles from January 1, 2002 to December 31, 2003. Seventy-one day 5 slow-frozen (SF) blastocysts were thawed and 59 embryos survived the thawing (83.1%). An average of 2.5 SF blastocysts was replaced per embryo transfer, resulting in a pregnancy rate of 16.7% (4/24). Concurrently, 41 vitrified (VIT) blastocysts were thawed and all 41 survived the thawing process (100%). An average of 2.0 VIT blastocysts was replaced per embryo transfer, resulting in a pregnancy rate of 50% (10/20). Survival, pregnancy and implantation rates of day 5 VIT blastocysts have significantly increased (P < 0.01, P < 0.02 and P < 0.01 respectively) over day 5 SF blastocysts. A similar trend was observed with day 6 blastocysts.

Clinical experience and perinatal outcome of blastocyst transfer after coculture of human embryos with human endometrial epithelial cells: a 5-year follow-up study

OBJECTIVE

To evaluate the reproductive and neonatal outcome of blastocyst transfer after coculture with human endometrial epithelial cells in IVF and oocyte donation.

DESIGN

Retrospective study. Private assisted reproductive center.

PATIENTS(S)

Two hundred sixty women undergoing IVF and 469 oocyte recipients.

INTERVENTION(S)

IVF or intracytoplasmic sperm injection (ICSI) and transfer of at least one blastocyst after coculture with human endometrial epithelial cells.

MAIN OUTCOME MEASURE(S)

Blastocyst formation rate, implantation and pregnancy rates, neonatal outcome, and congenital birth defects.

RESULT(S)

Among patients who had transfer with their own oocytes, 1193 of 2349 cocultured embryos developed up to the blastocyst stage (50.8%), and pregnancy and implantation rates of 33.9% and 19.2%, respectively, were achieved. In the oocyte donation program, 1819 blastocysts were obtained from 3127 embryos (58.2%), with subsequent pregnancy and implantation rates of 57.0% and 31.0%, respectively. The blastocyst rate remained stable throughout the 5 years of the study, but the pregnancy and implantation rates increased dramatically. Of 139 deliveries, 57 (41.0%) were multiple pregnancies and 1 (0.7%) was a multifetal birth (four live born infants). Out of 200 children born, 59% were male, and congenital birth defects were observed in 2.5%.

CONCLUSION(S)

Coculture of human embryos with endometrial epithelial cells yields a blastocyst formation rate of 50.8% to 58.2% and encouraging implantation and pregnancy rates. This technique reduces the mean number of embryos transferred in each patient. The number of embryos implanted is more relevant to neonatal outcome than is the coculture system and blastocyst transfer used. The risk of congenital birth defects associated with this program is similar to that recorded in early ET in IVF or ICSI.

Factors that determine discordant outcome from shared oocytes

OBJECTIVE

To investigate the factors that may be related to pregnancy in oocyte recipients who shared oocytes from the same donor and showed discordant pregnancy outcome.

DESIGN

Matched pair analysis.

SETTING

IVF academic center.

PATIENT(S)

Five hundred forty-two oocyte donation cycles that shared oocytes from 197 donors with discordant outcome.

INTERVENTION(S)

Egg donation and embryo transfer.

MAIN OUTCOME MEASURE(S)

Pregnancy rate and implantation rate.

RESULT(S)

Three hundred sixty-five matched-paired discordant outcome oocyte recipients were analyzed. Pregnant and nonpregnant recipients were similar in terms of age, serum E(2) levels, endometrial thickness, indications for oocyte donation, and abnormal sperm parameters. No differences were found in the number of oocytes received per patient, fertilization rate, IVF/intracytoplasmic sperm injection (ICSI) distribution, embryo quality, or on embryo transfer difficulty.

CONCLUSION(S)

Discordant pregnancy outcome could not be explained by the different egg recipients and cycle factors studied. In addition to chance, other factors must be investigated that could explain discordant outcome in egg recipients sharing oocytes from single donors.

Successful freezing and thawing of blastocysts cultured in sequential media using a modified method

OBJECTIVE

To evaluate the clinical role of blastocyst freezing and thawing after prolonged culturing in sequential media.

DESIGN

Retrospective analysis of 293 blastocyst freeze-thawing cycles.

SETTING

University hospital infertility unit.

PATIENT(S)

Nonselected couples undergoing IVF.

INTERVENTION(S)

Blastocysts were frozen and thawed by a modified method.

MAIN OUTCOME MEASURES

Blastocyst recovery after freeze-thawing and pregnancy rates after the transfer. Evaluation of the effect of the number of transferred blastocysts, the method of IVF, and of the woman's age on the results achieved by frozen-thawed blastocysts.

RESULT(S)

Frozen-thawed blastocysts provided a 29.5% clinical pregnancy rate per transfer. After the transfer of three blastocysts the pregnancy rate was 42.0%, and after the transfer of one or two blastocysts it was approximately the same (25.0% and 28.0%, respectively). The method of IVF did not affect pregnancy rates, but the increasing age of the woman did. Pregnancies were characterized by a low abortion rate (8.0%) regardless of the age of the woman.

CONCLUSION(S)

A modified method for blastocyst freeze-thawing provides good clinical results. It offers the possibility for a single-thawed blastocyst transfer and represents a good alternative for older women because of its lower risk of spontaneous abortion.