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

Abstract

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.

The effects of blastocyst morphological score and blastocoele re-expansion speed after warming on pregnancy outcomes

“…With refinements in embryo cryopreservation technology in recent years allowing almost all embryos to survive the vitrification/warming process, vitrified-warmed embryo transfer (VET) has become increasingly common. VET is advantageous in that it effectively prevents in vitro fertilization-associated complications such as ovarian hyperstimulation syndrome [ 1 ], is associated with better obstetric and perinatal outcomes [ 2 ], and maximizes the embryo utilization rate and increases the cumulative pregnancy rate [ 3 4 ], particularly for slowly developing embryos [ 5 ] and patients exhibiting early progesterone elevation [ 6 ].…”

Matrix Metalloproteinase 13 Activity is Required for Normal and Hypoxia-Induced Precocious Hatching in Zebrafish Embryos

“…Despite a detailed understanding of the cell biology of the early mammalian embryo [65,66] and implantation [64,67], blastocyst hatching has not been studied extensively. Implantation rates are improved in a delayed implantation model that extends blastocyst quiescence prior to implantation [68], perhaps by providing more time for the embryo to express and activate the proteases necessary to digest the ZP and/or ECM of the uterine lining. Current standard practice for human in vitro fertilization is to transfer expanded blastocysts after in vitro culture [65]; however, even expanded blastocysts often fail to hatch after transfer [68].…”

“…Implantation rates are improved in a delayed implantation model that extends blastocyst quiescence prior to implantation [68], perhaps by providing more time for the embryo to express and activate the proteases necessary to digest the ZP and/or ECM of the uterine lining. Current standard practice for human in vitro fertilization is to transfer expanded blastocysts after in vitro culture [65]; however, even expanded blastocysts often fail to hatch after transfer [68]. Assisted-hatch techniques such as zona-scratching to improve in vivo hatching have shown promising but inconsistent results [69].…”

“…Assisted-hatch techniques such as zona-scratching to improve in vivo hatching have shown promising but inconsistent results [69]. By extending blastocyst culture time and transferring only spontaneously hatched blastocysts, Chimote and colleagues improved implantation success and live birth rate, thereby demonstrating that successful hatching is a better prognostic marker for in vitro fertilized embryo selection than blastocyst expansion [68]. Although hatching itself is ubiquitous across taxa, it is unclear if the molecular mechanisms of hatching are conserved.…”

Lysophosphatidic acid accelerates development of porcine embryos by activating formation of the blastocoel

“…In conclusion, the addition of LPA into the medium can affect the developmental potential of porcine parthenogenetic embryos by accelerating the kinetics of blastocyst formation, resulting in the production of more good‐quality blastocysts. A major focus of many investigations is promoting the development of healthy blastocysts, especially those with high rates of hatching, and improving embryo transplantation potential (Balaban et al, ) because transfer of this class of embryos is associated with improved rates of implantation and pregnancy (Khorram, Shapiro, & Jones, ; Yoon, Yoon, Son, Im, & Lim, ) as well as the live birth (Chimote, Chimote, Nath, & Mehta, ). LPA was previously shown to stimulate fibroblast DNA synthesis and proliferation, thus acting as a growth factor (Kobayashi et al, ); similar signaling could promote cell divisions in embryos, based on our findings that LPA improved the developmental potential of parthenogenetic porcine embryos beyond the 8‐cell stage.…”