Background: The implementation of assisted reproductive techniques (ART) is a complex treatment requiring both a good cooperation between various professional groups in the fertility centre, and the patient's and her partner's cooperation. Accordingly, there are many sources of failure, such as using the wrong medication or not considering optimal times. If there is an artificial application of the ovulation induction injection, the success of the treatment is endangered and in some cases the cycle is discontinued, if the patient failed to administer the drug correctly. An alternative to cycle cancellation might be the maturation of the oocytes in vitro ., We Report: on a 31-year-old patient in whom we performed an oocyte retrieval procedure 24 hours after triggering ovulation followed by in vitro maturation of the immature oocytes over a period of more than 12 h. The treatment resulted in a healthy, ongoing pregnancy., (©by Acta Endocrinologica Foundation.)