Inter-generational effects of the in vitro maturation technique on pregnancy outcomes, early development, and cognition of offspring in mouse model

In vitro maturation (IVM) of oocytes has been a highly successful method for avoiding the occurrence of severe ovarian hyperstimulation syndrome in some patients during in vitro fertilization. However, the safety of the protocol, especially the long-term effects, is still an issue of debate. The current study is to investigate the long-term effects of IVM on mice through two generations and reveal its inter-generational effects as well. The data indicate that the rates of embryo resorption and fetal death in the F1 generation were significantly increased while the newborn survival rate in the F1 and F2 generations were significantly decreased in the IVM group. Increased body weights in the F1 generation and mouse number per litter in the F2 generation were observed in both the IVM and VVM groups; however, no insulin resistance was detected. No significant differences were detected in birth defects, organ weights, testis histology and sperm motility, estrous cycle, and cognition among the IVM, VVM and N mice in either the F1 or F2 generations. Our results suggest that mouse IVM can affect pregnancy outcomes throughout two generations. IVM does not appear to influence the development and cognition of the offspring throughout two generations.