Controlled natural cycle IVF with antagonist use and blastocyst transfer

By Dr. Krinos Trokoudes, MB Minbattiwalla, L Kalogirou, K Pantelides, P Mitsingas, A Sokratous, A Chrysanthou, SJ Fasouliotis

Many strategies of treatment with respect to stimulation protocols and laboratory procedures are available to increase fertilization and pregnancy rates in patients undergoing IVF. Many patients produce poor quality oocytes even after the administration of high doses of gonadotrophins, resulting in poor embryo development and reduced chances of pregnancy. Eventually, the infertile couple experiences physical, social and economical burden upon repeated cycle failure.

Ovarian stimulation exposes women to the risk of ovarian hyperstimulation syndrome (OHSS), a well recognized and potentially fatal complication in assisted reproduction. Furthermore, transfer of a higher number of embryos to compensate for poor implantation rates per embryo transfer encompasses the risk of multiple pregnancies, while fetal reduction constitutes another major complication from stimulated cycles. With high overall fi nancial costs per IVF–embryo transfer trial, the ovarian stimulation method of assisted reproduction limits the possibility for couples to undergo repeated IVF cycles in case of failure.

Controlled natural cycle IVF (CONCIVF), on the other hand, represents a simpler and shorter treatment method, eliminating the risks of OHSS and iatrogenic multifetal pregnancies (Cohen, 1998). Being relatively cheap (Nargund et al., 2001), it encourages patients to undergo repeated IVF attempts over consecutive cycles as ‘ovarian recovery’ is not an issue between cycles.

The aim of this study was to evaluate the effect of natural cycle IVF on implantation and pregnancy rates. Based on previous literature reports suggesting higher implantation rate by extending embryo culture to the blastocyst stage (Gardener et al., 1998), extended culture of single oocytes was adopted in this study, in order to investigate its effect on CONCIVF.

This site is registered on as a development site. Switch to a production site key to remove this banner.