New female infertility study findings have been reported by Q. Sun and co-researchers.

According to recent research from Shanghai, People's Republic of China, "One of the technical bottlenecks in producing nonhuman primate models is that current assisted reproductive techniques, such as in vitro culture and frozen conservation of multicell-stage embryos, often result in poor embryo quality and subsequently lead to low birth rates. We investigated whether pronuclear embryo transfer can be used as an effective means for improving pregnancy and live birth rates of nonhuman primates."

"We collected 174 metaphase II oocytes by laparoscopy from 22 superovulated mature females and then fertilized these eggs using either in vitro fertilization or intracytoplasmic sperm injection, resulting in a 33.3% and a 50% fertilization rate, respectively. These 66 fertilized pronuclear-stage embryos were then tubally transferred to 30 recipients and led to 7 births and 1 abortion. Importantly, we observed that the highest live birth rate of approximate to 64% was obtained when the transfer of pronuclear embryos was performed in the presence of new corpus luteum in the ovary of recipients between 24 h and 36 In after estradiol peak. Therefore, our experiments demonstrate that by matching the critical time window in the recipient's reproductive cycle for achieving optimal embryo-uterine synchrony, pronuclear embryo transfer technology can significantly improve the pregnancy rate and live birth of healthy baby monkeys," wrote Q. Sun and colleagues (see also Female Infertility).

The researchers concluded: ...