The purpose of this study is to determine whether oocyte and embryo mechanical properties measured during in vitro fertilization can predict embryo development outcomes and clinical pregnancy.
In the current practice of in vitro fertilization (IVF), clinicians often transfer multiple embryos to the patient at once in an effort to maximize chances of pregnancy. This practice results in a high rate of multiple births which increase the risks of complications for mothers and children. The investigators in this study have developed a novel, noninvasive marker of embryo viability which is based on measuring embryo mechanical properties at the oocyte or the 1-cell stage. The investigators would like to test whether human oocyte or embryo mechanical properties are predictive of subsequent development, clinical pregnancy, and compare their predictive power to that of a morphological assessment (the current gold standard). Using this approach, clinicians could more confidently move toward single embryo transfer, provided more individualized counseling for patients undergoing oocyte cryopreservation, as well as improve pregnancy rates after IVF. This is a pilot observational study. Although investigators will measure the mechanical properties of all participant oocytes and embryos, no prediction of embryo viability will be made, and there will be no intervention in choosing which embryos to transfer to participants. The data from this study will eventually be used to find a range of oocyte and embryo mechanical parameters which are predictive of high developmental potential, and will serve as the basis for an interventional study in the future.
Study Type
OBSERVATIONAL
Enrollment
119
An oocyte or embryo will be gently held by a micropipette, and a small inward pressure will be applied to the edge of the oocyte or embryo. The response of the embryo to this pulling force will allow the investigators to measure its stiffness and viscosity. The term "micropipette aspiration" refers to the pressure applied to the edge of the embryo -- this procedure is not invasive and does not involve any sort of puncture or removal of material from the oocyte or embryo.
Stanford University IVF clinic
Stanford, California, United States
Shenzhen Army and Police Hospital--Reproductive Unit
Shenzhen, China
Taiwan IVF Group
Hsinchu, Taiwan
Clinical pregnancy (8-10 weeks)
Positive result is determined by presence of intrauterine gestational sac and fetal heartbeat. Outcome will record number of gestational sacs with heartbeat present.
Time frame: 8-10 weeks
Blastocyst grade (Gardner scale)
If the embryo reaches the blastocyst stage, its inner cell mass and trophectoderm will be graded according to Gardner's criteria. If no blastocyst is formed, that will be recorded as well.
Time frame: 5-6 days
Pregnancy test result (based on human chorionic gonadotropin (hCG) levels)
Outcome will be recorded as either positive or negative.
Time frame: 2-3 weeks
Clinical pregnancy (5-6 weeks)
Positive result is determined by presence of intrauterine gestational sac and fetal heartbeat (although sometimes the heartbeat does not show up for another week or two). Outcome will record number of gestational sacs.
Time frame: 5-6 weeks
Fertilization rate
For oocytes measured, the fertilization of oocytes will be recorded.
Time frame: 1 day
Day 3 morphology
For oocytes measured, the day 3 morphology of embryos will be recorded.
Time frame: 3 days
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