1990 Volume 39 Issue 2 Pages 291-294
This paper describes the rate of naturally occurring abortion and fetal death that were diagnosed by the use of an ultrasonographical device in 683 pregnant cynomolgus monkeys (Maraca fascicularis) of which 542 were wild-imported monkeys and 141 were colony-bred monkeys. All of these animals had become pregnant by the 3day timed mating system. The combined rate of abortion and fetal death was 7.0% in the wild-imported animals and 7.8% in the colony-bred animals. There were no significant differences in the rate with respect to different ages and to different period of feeding at Tsukuba Primate Center. Seventy-eight per cent (38 monkeys) of the total cases occurred during the first 5 to 9 pregnancy-weeks.