Comparison of pregnancy rates following frozen embryo transfer according to the reason for freezing: risk of ovarian hyperstimulation vs inadequate endometrial thickness.

Purpose: To determine the relative pregnancy rates following frozen embryo transfer according to the reason for deferring fresh embryo transfer and freezing all embryos.

Method: A retrospective review over a 10-year time period of all in vitro fertilization (IVF) cycles that deferred fresh transfer and cryopreserved all embryos related to risk of ovarian hyperstimulation syndrome or if there was inadequate endometrial thickness. Pregnancy rates according to the reason for freezing were then compared.

Pregnancy outcome following fresh vs frozen embryo transfer into gestational carriers using a simplified slow freeze protocol.

Purpose: To compare pregnancy rates following fresh vs frozen embryo transfer into gestational carriers.

Methods: Choice of deferring fresh embryo transfer and cryopreserving the embryos vs fresh transfers was not randomized but based on circumstances. The cryopreservation protocol used a simplified slow cool technique avoiding the planar programmable freezer and using a one-step removal of the cryoprotectant.

Speculum retention during embryo transfer does not improve pregnancy rates following embryo transfer--a randomized study.

Purpose: To corroborate or refute two previous studies that suggested that a technique using prolonged speculum retention may improve pregnancy rates per embryo transfer.

Methods: Women undergoing day 3 embryo transfer were randomly assigned to the conventional transfer technique vs the speculum retention technique. The speculum retention technique involves following the embryo transfer not to withdraw the speculum but to loosen the screw in order to exert gentle pressure on the portiovaginalis of the cervix and leave it in for seven minutes.

Evidence that the main adverse effect of ganirelix on pregnancy and implantation rates is on the embryo rather than the endometrium.

Purpose: To compare pregnancy rates following the transfer of thawed frozen embryos according to the type of GnRH antagonist or agonist used during controlled ovarian hyperstimulation (COH).

Methods: Retrospective review of frozen embryo transfers according to whether a GnRH agonist or antagonist was used. Furthermore to determine if a specific antagonist/agonist resulted in higher pregnancy rates than the other.

Effect of multiple source vs single source of donor embryos on pregnancy and implantation rates per transfer.

Purpose: To evaluate whether using donated embryos from more than one source has a negative impact on pregnancy rates compared to a single source.

Methods: Retrospective review of all donor embryo transfers that occurred in our IVF center over a 10-year period. Embryos were all from our own patient pool.