The impact of ovarian stimulation on implantation and fetal development in mice.
The objective of this study was to evaluate, using an embryo donation model, whether impaired oocyte/embryo developmental competence and/or changes in uterine milieu are responsible for the previously observed adverse effects of superovulation with gonadotrophins on implantation and fetal development in mice. Embryos from superovulated and non-stimulated females were transferred to separate uterine horns within the same superovulated or non-stimulated pseudopregnant recipient mice. Embryo development was impaired as a significantly higher proportion of normal embryos from control donors (61%) were blastocysts on transfer day compared with superovulated donors (41%; P = 0.001). The implantation rate in control recipients was significantly reduced after transfer of embryos from superovulated donors (12%) compared with control donors (25%; P = 0.001). Uterine receptivity was impaired in superovulated recipients. The implantation rate of control embryos was significantly higher in control (25%) than in superovulated recipients (7%; P = 0.001). Transfer of embryos recovered from superovulated donors resulted in significantly higher post-implantation fetal mortality in superovulated recipients (69%) than in control recipients (36%; P = 0.01), and the mean weight of live fetuses was significantly lower for fetuses obtained from superovulated recipients (0.51 g) compared with that of fetuses obtained from control recipients (0.72 g; P = 0.006). Hence, ovarian stimulation appears to impair oocyte/embryo quality as well as uterine milieu.
Ertzeid
G
G
Department of Obstetrics and Gynecology, The National Hospital, University of Oslo, 0027 Oslo, Norway. gudvor.ertzeid@rikshopitalet.no
Storeng
R
R
D000818:Animals; D006063:Chorionic Gonadotropin / Q000008:administration & dosage / Q000009:adverse effects; D010064:Embryo Implantation; D004624:Embryo Transfer; D005314:Embryonic and Fetal Development; D005260:Female; D006064:Gonadotropins, Equine / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010062:Ovulation Induction / Q000009:adverse effects*; D011247:Pregnancy; D014599:Uterus / Q000187:drug effects / Q000502:physiology
D006063:Chorionic Gonadotropin; D006064:Gonadotropins, Equine