Abstract
CL/Fr mice were fasted for 24 or 48 hours in various stages during midpregnancy, and the incidence of intrauterine death and cleft lip in live fetuses were examined at term. Cleft lip occurrence and intrauterine death were not changed by 24-hr-fasting. By 48-hr-fasting, intrauterine death increased significantly, but cleft lip frequencies were not changed in groups treated on other than days 8-9. In the group treated on days 8-9, the cleft lip frequency decreased significantly to 14% (control, 29%), although intrauterine death was not different from the control. This suggested that the cleft lip embryos were preferentially killed by maternal fasting on days 8-9 of pregnancy.
