In a recent issue of human reproduction, a scholarly journal from Oxford Academic, we found this summary of a study on timing of egg retrieval and embryo transfer. The study question was posed “Does the time from ovum pick-up (OPU) to frozen embryo transfer (FET) affect reproductive outcomes in a freeze-all strategy?” The findings were interesting.

Research in the past several years has found an advantage to not transferring fresh embryos during an IVF cycle in favor of freezing all embryos for a later frozen embryo transfer (FET). A remaining question is whether it is best to let a couple of months pass to allow the woman’s body to normalize before doing the FET. Recent research out of Spain indicates that there may be no need to wait one or more months after freezing all embryos before performing FET.

In a retrospectively study of 512 freeze-all cycles, researchers compared pregnancy results from 263 FETs that occurred in the first menstrual cycle following egg retrieval with 249 FETs that occurred later. Live birth rates were not poorer when FET were performed immediately following the IVF/egg retrieval. Neither did they find a difference for biochemical pregnancy, clinical pregnancy, or pregnancy loss.

Photo Credit: ZEISS Microscopy