Abstract The aim of this study was to investigate the effect of delaying maturation by extended culture of immature bovine oocytes in prematuration medium (PMC) containing single maturation inhibitor on their meiotic resumption and embryonic development. Bovine immature oocytes were cultured in M199 containing 10 μM of either inhibitor (roscovitine, cilostamide, or forskolin) for either 72 or 120 h followed by up to 48 h in maturation media supplemented with 7.5 IU follicle-stimulating hormone (FSH)/luteinizing hormone (LH). Two control groups were used. In untreated control, immature oocytes were cultured in the same medium as the experimental group without any inhibitors. In the FSH/LH control group, oocytes were cultured directly in the maturation medium supplemented with FSH/LH up to 48 h. In vitro matured oocytes were then inseminated with frozen-thawed bull sperm. Fertilization, defined as two-cell division 48 h post-insemination, and blastocyst formation were recorded. Total maturation rate for the 72-h group was 73%, 70%, 66%, and 69% for roscovitine, forskolin, cilostamide, and FSH/LH control, respectively, with no significant difference indicating that inhibitors have no negative effect on the oocyte maturation rate. The total fertilization rate for the 72-h group revealed that cilostamide (47%) and roscovitine (35%) were significantly higher than FSH/LH control (20%). The total blastocyst formation rates per inseminated oocytes revealed that among treatment groups, roscovitine (20%) had significantly higher rate than forskolin (9%). Overall, 72-h exposure period had better outcomes than 120 h in all the treated groups. In conclusion, prematuration culture of the bovine oocytes in the presence of maturation inhibitor for 72-h period at 10 μM concentration is sufficient in improving the bovine oocyte developmental competence.

Abstract OBJECTIVE: To study the probability of ovulation and subclinical abortion during long-term use of Norplant and to assess the concomitant endometrial development. DESIGN: This was a prospective nonrandomized comparative study. The ovaries and endometrium were assessed daily by ultrasonography during 59 menstrual cycles in 50 women who were using Norplant for > 1 year. Serum concentrations of E2, P, FSH, LH, pregnancy specific beta 1 glycoprotein (Sp1), and hCG were also daily measured. The findings were compared with those in 35 ovulatory cycles in normal fertile women not using contraception. SETTING: Clients of the Family Planning Clinic of Assiut University Hospital (Norplant users) and the hospital women staff (controls). RESULTS: Sonographic and hormonal evidence of ovulation were observed in one third of Norplant users; two of them resulted in conception. However, the majority of these ovulatory cycles showed low midcycle peaks of E2, FSH, and LH and evidence of luteal phase defect (LPD). Excessive follicular enlargement was observed in 46% of the cycles. Norplant users had significantly thinner endometrium that did not exhibit the normal phasic changes in sonographic texture. Apart from conceptive cycles, no rise in Sp1 or hCG was observed. CONCLUSIONS: Norplant acts mainly by inhibiting ovulation, but when this occurs, it is associated with LPD and subnormal endometrial development. Subclinical abortion does not contribute to the contraceptive effect.

Abstract OBJECTIVE: To study the probability of ovulation and subclinical abortion during long-term use of Norplant and to assess the concomitant endometrial development. DESIGN: This was a prospective nonrandomized comparative study. The ovaries and endometrium were assessed daily by ultrasonography during 59 menstrual cycles in 50 women who were using Norplant for > 1 year. Serum concentrations of E2, P, FSH, LH, pregnancy specific beta 1 glycoprotein (Sp1), and hCG were also daily measured. The findings were compared with those in 35 ovulatory cycles in normal fertile women not using contraception. SETTING: Clients of the Family Planning Clinic of Assiut University Hospital (Norplant users) and the hospital women staff (controls). RESULTS: Sonographic and hormonal evidence of ovulation were observed in one third of Norplant users; two of them resulted in conception. However, the majority of these ovulatory cycles showed low midcycle peaks of E2, FSH, and LH and evidence of luteal phase defect (LPD). Excessive follicular enlargement was observed in 46% of the cycles. Norplant users had significantly thinner endometrium that did not exhibit the normal phasic changes in sonographic texture. Apart from conceptive cycles, no rise in Sp1 or hCG was observed. CONCLUSIONS: Norplant acts mainly by inhibiting ovulation, but when this occurs, it is associated with LPD and subnormal endometrial development. Subclinical abortion does not contribute to the contraceptive effect.