In-vitro fertilisation (IVF) with Natural Cycle focuses on the egg that has been selected spontaneously that month. It is fertilised in in-vitro culture conditions in the laboratory with spermatozoids that may have been isolated from a semen sample (from the husband/partner or from an anonymous donor) or obtained through a testicular biopsy.
This type of treatment is usually used in patients that have had a low yield in previous IVF cycles and who discard a donation of eggs, or in patients who discard ovary stimulation because they suffer from some illness that could worsen with increased levels of oestrogen or because they simply do not want to choose that course of action. The expected gestation rate of this type of cycle is very variable according to the age, ovary reserve, masculine factor and base pathology.
The follicle development is usually followed up using transvaginal ultrasound, sometimes together with blood analysis.
One variation of natural IVF is assisted natural IVF, which consists in administering low doses of gonadotrophines and GnRh antagonist in the last days of follicle development to accompany this last stage and to better coordinate the date of the follicle puncture.