Impact of Blood Clot in Oocyte-Corona-Cumulus Complex during in vitro Fertilization and Embryo Transfer

Objective To study the impact of blood clots in the oocyte-corona-cumulus complexes （OCCC） during in vitro fertilization and embryo transfer （IVF-ET）.Methods The OCCCs were harvested from the patients undergoing long protocol ovarian hyperstimulation. The OCCCs with blood clots removed or not, were randomly grouped into A or B. The OCCCs without blood clots were group C （the control）.Results The patient＇s age, infertility duration, the average GN consumption, the average days of superovulation and an average number of harvested oocytes showed no significant difference in the 3 groups. The fertilization rate and 2PN rate in group A were the highest, which were 85.4% and 71.1%, respectively, followed by group C, which were 77.5% and 64.9%, respectively. The lowest fertilization rate and 2PN rate were in group B, 75.8% and 62.2%, respectively. Those in group A were significantly higher than those in groups B and C （P〈0.01）, while there was no significant difference between group B and group C. The implantation rates and pregnancy rates showed no significant difference in the 3 groups after transplantation, even if group A got the highest rate among the 3 groups. Conclusion Removing the blood clots in OCCC can improve the outcome of IVF-ET without increasing the cost and complexity of the operation.

Incidence and Potential Causes affecting Monozygotic Twin Formation Following in vitro Fertilization and Embryo Transfer

Objectives To study the incidence and potential causes of monozygotic twins after in vitro fertilization and embryo transfer （IVF-ET）. Methods A retrospective study was performed on women carrying monozygotic twins （MZTs） after conventional IVF-ET treatment at the Third Affiliated Hospital of Guangzhou Medical College in China from January 2003 to May 2009. The incidence and the miscarriage rate for MZTs following IVF-ET were examined iin relation to maternal age, duration of infertility, type and dose of hormone treatment, conventional IVF-ET cycles versus intracytoplasmic sperm injection （ICSI） cycles, the use of fresh or frozen-thawed embryos, and day （post-fertilization） of embryo transfer. Results Sixteen MZT pregnancies occurred in 2 161 patients （incidence of 0.74%）, of which 5 miscarried （31.25%）. No significant difference was found between MZT and non-MZT groups in terms of maternal age, duration of infertilit）, duration of gonadotropin （Gn） administration, dosage of Gn, number of oocytes retrieved, number of oocytes fertilized, or number of embryos transferred （P〉O.05）. The incidence of MZT was not statistically different between conventional IVF-ET cycles and ICSI cycles, between fresh embryos transfer cycles and frozen-thawed embryo cycles, or between different transfer days （P〉0.05）. Conclusion The incidence of MZTs following IVF-ET treatment greatly exceeds that observed following spontaneous conception. Intracytoplasmic sperm injection, frozenthawed procedures, and embryo transfer on different days were not correlated with an increased incidence of MZT pregnancies.