Superovulation of female mice delays embryonic and fetal development

Abstract

Mouse and human embryos, cultured in vitro, undergo a delay in development compared with those grown in vivo. This delay can be caused by suboptimal culture conditions, but possible influences of ovarian stimulation cannot be excluded. The objective of this study was to test the hypothesis that both in vitro and in vivo, preimplantation embryonic development and postimplantation fetal development are impaired in superovulated female mice when compared with naturally cycling controls. A delay in in-vitro blastocyst hatching and in-vivo blastocyst formation (P < 0.03 and P < 0.0001 respectively) and a 40% fetal growth retardation (P < 0.0001) were observed after superovulation in comparison with naturally cycling controls. After transfer to non-stimulated foster mothers, blastocysts from stimulated females had a lower implantation rate (P < 0.005), and developed into fewer living fetuses (P < 0.02), more resorption sites (P < 0.02) and had more pronounced growth retardation (P < 0.0001) when compared with blastocysts from naturally cycling controls. In conclusion, superovulation in the mouse causes a delayed embryonic development in vitro and in vivo, an increased abnormal blastocyst formation, a pronounced fetal growth retardation, and an increased number of resorption sites. If this observation in mice can be extrapolated to humans, it may offer an explanation for the delay in embryonic development and the low birth weight observed after IVF.

Improvement of mouse embryo quality by myo-inositol supplementation of IVF media

“…In the laboratory mouse, for example, it produces a delay in preimplantation development of 2 to 7 h per cycle [18,39]. Depending on the strain of mice analyzed, during in vivo In light of these data, it has been calculated that embryos maintained in vitro throughout preimplantation development may be delayed by an entire day at the blastocyst stage [12,37,49]. The processes of compaction, blastulation and blastocyst expansion are thus completed in vitro with progressively increasing temporal delays, likely leading to a loss of developmental competence and a reduction in the chance of pregnancy.…”

The long-term effects of superovulation on fertility and sexual behavior of male offspring in mice

“…It has been reported that superovulation of female mice delayed embryonic and fetal development [3,34]. The possible explanation is that superovulation increases the proportion of chromosomal abnormalities in oocytes in rats and uterine horn is incapable of nourishing large number of blastocysts tyring to implant and also to develop in to a fetus [35].…”

“…It has been common practice to treat infertility in humans. The use of high dose of exogenous hormones has recently caused much debate surrounding their effects on oocyte maturation [3,4]. Because imprint acquisition has been shown to occur relatively late in oogenesis, the establishment of these imprints may be susceptible to exogenous hormone treatments [5][6][7].…”

Efficacy of native and hyperglycosylated follicle-stimulating hormone analogs for promoting fertility in female mice

“…First, both rhFSH and PMSG therapies adversely effect the uterine environment in mice resulting in a reduced pregnancy rate compared to randomly cycling adult females (17)(18)(19). Second, despite a significant increase in the number of developing embryos present following ovarian hyperstimulation, the litter size is physiologically restrained by the physical limitations of the mouse uterus (20).…”