Low Implantation Potential Research Articles

The late cleaved and rescue intracytoplasmic sperm (ICSI) embryos, frozen cycle is better than fresh cycle

Late cleaved and rescue ICSI embryos have low implantation potential in fresh embryo transfer cycles, due to embryo-endometrium asynchrony. The aim of this study was to compare the pregnancy potential of the late cleaved embryos on day 3 and rescue ICSI embryos in frozen-thawed and fresh embryo transfer.

Embryos exhibiting abnormal first cytokinesis phenotypes are associated with poorer embryo development and lower implantation potential

Combined with timing of the 2nd and 3rd cytokinesis, a prolonged 1st cytokinesis duration has been reported to correlate with low blastocyst formation and reduced expression of cytokinesis genes (Wong et al, 2010). This study determined the incidence of a novel abnormal 1st cytokinesis phenotype, evaluated the duration of 1st cytokinesis, and assessed clinical relevance.

The late cleaved embryos, frozen cycle is better than fresh cycle

In general, the late cleaved-embryos have low implantation potential in fresh embryo transfer cycles, may be due to embryo-endometrium asynchrony. However, FETs seems to improve embryo-endometirium synchrony by control of thawing day. The aim of this study is to compare the implantation potential of the late cleaved-embryos (≤6 cell) on day 3 in frozen thawed embryo transfers and Fresh embryo transfers.

Pregnancy Rates Following the Exclusive Transfer of Twice Frozen Twice Thawed Embryos Using a Modified Slow Cool Cryopreservation Technique

BACKGROUND: To maximize the success rate from a given in vitro fertilization (IVF) cycle it is essential to have a good cryopreservation program. An efficient cryopreservation program maximizes the number of babies produced per oocyte harvest, and saves patients money by eliminating the need for multiple oocyte retrieval. However, it is often necessary to thaw extra cryopreserved embryos to choose the ones with the best morphology for transfer. Although they can be refrozen, these supernumerary de-selected embryos may have lower implantation potential than the ones originally chosen for transfer, due to inferior morphology.

Odd cell stage embryos: are they unequal?

OBJECTIVE: Unequally sized embryos are considered as embryos with a lower implantation potential. The aim of this study was to evaluate the equality in odd cell stage embryos using the blastomere volume as a new morphological characteristic.

Comparison of implantation rate between GnRH agonist and antagonist cycles according to E2 level

High E2 level during COH in both GnRH-agonist and antagonist cycles may affect embryo implantation, while E2 level on hCG is higher in GnRH agonist than in antagonist cycles. GnRH antagonist cycles have been reported a lower pregnancy (PR) and implantation rate (IR) than agonist cycles. To evaluate whether lower E2 level on hCG in GnRH-antagonist cause lower implantation potential than GnRH-agonist cycles, we compare IR between two groups according to E2 level on hCG administration.

Transfer of nonselected transferable day 3 embryos in low embryo producers

Objective To examine the implantation potential of embryos from assisted reproductive technology cycles with low embryo production and to assess the effects of clinical variables and embryo scores (ES) on pregnancy outcome. Design Prospective clinical study. Setting Assisted reproductive technology unit in a tertiary medical center. Patient(s) From July 1998 to December 2001, 280 cycles in 229 infertile couples produced a limited number of one, two, or three embryos 3 days after oocyte retrieval and underwent fresh embryo transfer (ET). Intervention(s) Embryos with two or more blastomeres were scored and transferred. Main outcome measure(s) ES and implantation rate per ET. Result(s) Of 863 fresh ET cycles during the study period, 32.4% (280) were low embryo producers. Among them, there were no significant differences in average ES of individual embryos in single, dual, or triple ET or in embryos obtained from patients with low or high E 2 responses, or young or old age. Embryos derived from conventional IVF had a better ES than those derived from intracytoplasmic sperm injection. The clinical pregnancy rate was strongly correlated with the cumulative ES. Implantation rates were similar among and between groups, with an average rate of 15.9%. Conclusion(s) Embryos of low embryo producers had an inherently low implantation potential that appeared to be unrelated to the number of embryos transferred, female age, ovarian E 2 genesis, or fertilization method. The cumulative ES can serve as a predictor of pregnancy.

Frequency of aneuploidy among women with poor prognosis and recurrent implantation failure

Objective: Reproductive failure associated with advanced maternal age is believed to be primarily as a result of an increase in frequency of meiotic non-disjunction in the aging oocyte. The end result being the generation of chromosomally abnormal embryos with lower implantation potential. What remains unclear is if the same phenomena can be observed in a subgroup group of infertile women with poor prognosis and repeated reproductive failure despite IVF treatment, regardless of age.

Using the male gamete for assisted reproduction: past, present, and future.

Using the male gamete for assisted reproduction: past, present, and future.

Transfer of nonassisted hatched and hatching human blastocysts after in vitro fertilization

Objective: To determine the feasibility of performing blastocyst transfer 6 days after oocyte insemination. Design: Retrospective clinical study. Setting: University-based IVF center. Patient(s): All cases of IVF over a 1-year span of time (June 1998–1999) in which seven 2PN embryos were available for transfer. Intervention(s): None. Main Outcome Measure(s): Implantation, pregnancy, and multiple pregnancy rates. Result(s): Transfer of blastocysts on days 5 and 6 resulted in implantation rates of 69% and 33% ( P=0.0006), clinical pregnancy rates of 89% and 59% ( P=0.05), and multiple pregnancy rates of 39% and 10% ( P=0.03), respectively. In cases in which blastocysts were spontaneously hatching or hatched on day 6 (9% of embryos), implantation and pregnancy rates were 52% and 80%, respectively. Embryos were successfully frozen in the hatched or hatching state with resultant clinical pregnancies. Conclusion(s): Transfer of embryos can be delayed to day 6 after oocyte insemination at which time a small percentage of embryos will hatch. Hatching of embryos by day 6 is a favorable prognostic factor for IVF outcome. Embryos that fail to hatch by day 6 may have a lower implantation potential. Difficulty with hatching embryos sticking to the transfer catheter was not encountered. Furthermore, hatching and hatched embryos can be frozen and with subsequent transfer result in pregnancies.