Assisted reproduction after cryopreservation of oocytes

Uvod: Kriopohrana jajnih stanica je metoda pomognute oplodnje kojom se stanice zamrzavaju na niske temperature u tekućem dušiku te ostaju pohranjene do trenutka oplodnje. Vitrifikacija je metoda izbora zamrzavanja koja nosi manje rizika za oštećenje oocita prilikom zamrzavanja i odmrzavanja. Indikacije za kriopohranu oocita mogu biti medicinske što obuhvaća žene s malignim bolestima i ostalim zdravstvenim problemima koja smanjuju plodnost te socijalne zbog osobnih razloga pacijentica. Cilj: Cilj istraživanja je bio utvrditi uspješnost vitrifikacije kao metode liječenja neplodnosti u njenim počecima i usporediti dva zakonom različito uređena razdoblja liječenja. Metode i pacijenti. Analizirana je medicinska dokumentacija 128 sekundarnih ICSI-ET ciklusa u pacijentica liječenih na Zavodu za humanu reprodukciju KBC-a Rijeka. Rezultati su prikazani i uspoređeni na osnovi postotnog računa. Rezultati: Udio pacijentica mlađih od 34 godine bio je 51%, prosječno su po ciklusu liječenja odmrznute 3-4 oocite. Udio prekinutih ciklusa do stadija oplodnje bio je 38%, a udio ciklusa s uspješnom oplodnjom jajnih stanica je bila 55-70%. Nije uočena tendencija manje uspješnosti oplodnje, kao ni lošijeg razvoja embrija prema starijoj reprodukcijskoj dobi pacijentica. Prijenos zametka je učinjen u 51% sekundarnih ICSI-ET ciklusa. Udio začeća na broj ukupno započetih ciklusa liječenja je bio 7%, odnosno na broj sekundarnih ciklusa s prijenosom zametaka 14%. Zaključak: Uspješnost liječenja u sekundarnom ICSI-ET ciklusu je manja u odnosu na prirodni mjesečni fekundabilitet. Najveći rizici obustavljanja liječenja su u fazi zamrzavanja i zagrijavanja oocita, odnosno u vrijeme oplodnje. Budući da se rezultati razlikuju prema ostalim istraživanjima koja ukazuju na manju uspješnost liječenja u starijih pacijentica mišljenja smo da je istraživanje potrebno nastaviti zbog relativno malog broja analiziranih ciklusa u ovom istraživanju.Introduction: Cryopreservation of oocytes is a method of assisted fertilization by which cells are frozen at low temperatures in liquid nitrogen and stored until fertilization. Vitrification is a method of choice that carries less risk of oocyte damage during freezing and thawing. Indications for cryopreservation of oocytes can be medical, which includes women with malignant diseases and other health problems that reduce fertility, and social for the personal reasons of patients. Aim: The aim of the research was to determine the success of vitrification as a method of infertility treatment in its beginnings and to compare two legally regulated treatment periods. Methods and patients: The medical documentation of 128 secondary ICSI-ET cycles in patients treated at the Department of Human Reproduction of the University Hospital Center Rijeka was analyzed. The results are presented and compared based on a percentage calculation. Results: The proportion of patients younger than 34 years was 51%, on average 3-4 oocytes were thawed per treatment cycle. The proportion of interrupted cycles to the stage of fertilization was 38%, and the proportion of cycles with successful fertilization of oocytes was 55-70%. There was no tendency of lower fertilization success, nor worse development of the embryo towards the older reproductive age of the patients. Embryo transfer was done in 51% of secondary ICSI-ET cycles. The proportion of conceptions in the number of total treatment cycles started was 7%, and in the number of secondary cycles with embryo transfer 14%. Conclusion: Treatment success in the secondary ICSI-ET cycle is lower compared to natural monthly fecundability. The greatest risks of discontinuation of treatment are in the phase of freezing and heating of oocytes, ie at the time of fertilization. Since the results are different from other studies that indicate lower treatment success in elderly patients, our opinion is that the study needs to be continued due to the relatively small number of cycles analyzed in this study