Ability of the ovine corpus luteum formed after follicle aspiration in the establishment and maintenance of pregnancy obtained from intrafallopian oocyte transfer

Aiming to evaluate the capability of sheep develop pregnancy after oocytes intra-fallopian transfer (OIFT), with corpus luteum (CL) formed after aspiration of the pre-ovulatory follicles, we used five adult ewes, without determined breed, after ovarian cyclicity confirmed by ultrasound. The females were submitted to estrus synchronization treatment, by inserting intravaginal device of slow release of natural progesterone (EZI-BREED CIDR OVINOS E CAPRINOS®, InterAg, New Zealand), being intramuscularly administrated 5 mg of dinoprost (Lutalyse®, Pfizer Laboratory Ltda., Brazil) on the fifth day from the beginning of the treatment. The vaginal device was removed on the fourteenth day and 500 IU of eCG was administered (Novormon®, Syntex Industries Biochemistry u0026 Pharmaceuticals SA, Argentina). After 48 hours from the use of gonadotropin, an ultrasound of the ovaries was performed to verify the presence of at least one follicle with a diameter equal to or greater than 5 mm, indicative of being pre-ovulatory. Thereafter, all visible follicles were aspirated guided by laparoscopy. The material aspirated from the follicles was evaluated in a stereomicroscope for the identification of complex cumulus oophorus (COCs), and the classification was performed with basis on the characteristics of ooplasma and cumulus cells. During the laparoscopic procedure, an artificial insemination with fresh diluted semen was conducted, depositing 100 x 106 of spermatozoa in each uterine horn. In three sheep, the OIFT was performed in the ipsilateral greater preovulatory follicle of the ovary of only one autologous COCs, which had homogeneous cytoplasm and expanded cumulus. This procedure was not performed in two sheep, since they did not present the appropriate COCs to the established criteria. The number of recovered COCs on the three recipients was identical to the aspired follicles, demonstrating the impossibility of the occurrence of spontaneous ovulations or the presence of residuals oocytes after the LOPU. The ultrasonographic monitoring of the ovaries was performed for the LCs confirmation, and the number of luteal structures formed corresponded to the pre-ovulatotios follicles vacuumed in each sheep. An ultrasonographic diagnosis of pregnancy was performed after 35 days of the OIFT, and two from the three recipients were diagnosed as pregnant, with the fetus and fetal wraps presenting characteristics consistent with gestational age in relation to the date of OIFT. The parturition occurred 151 days post-transfer in one of the females and 153 days in the other, with the birth of a lamb for each recipient, without clinical changes during the immediate postpartum period. Thus, it was shown that it is possible the establishment and development of normal gestational after OIFT in recipients with CL formed after aspiration of follicles guided by laparoscopy. Further studies are needed to better understand the potential of these biotechnological procedures.