Frequency of prenatal loss in a macaque breeding colony.

An accurate knowledge of the historical incidence of prenatal loss is essential for management of breeding colonies and for performing developmental toxicity studies in nonhuman primates. Data from the California Regional Primate Research Center indoor (timed-mated) and outdoor (random-mated) colonies of rhesus, cynomolgus, and bonnet macaques (Macaca mulatta, M. fascicularis, and M. radiata) were evaluated for a 10 year breeding period from 1984 to 1993. Pregnancy outcome data for the three species of macaques summarized in this report indicate that early pregnancy as well as term are vulnerable periods of gestation in terms of prenatal loss. Prematurity as well as twinning were additionally associated with elevated rates of loss during the prenatal or neonatal period. The incidence of pregnancy failure did not appear to be related to different housing/management conditions (i.e., indoor timed-mated vs. outdoor random-mated), parity, animal handling, shipping, or relocation. Some of the annual fluctuations in abortions could be related to disease outbreaks (e.g., measles, pneumonia) in the colony. These data will be invaluable in planning for research needs which focus on developmental biology and perinatology, and in interpreting the significance of abortions following exposure to experimental agents in small numbers of animals. © 1996 Wiley-Liss, Inc.