Frequency of prenatal loss in a macaque breeding colony

Abstract

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 (Mucacu mulutta, M . fascicularis, and M . radiutu) 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 housinglmanagement 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. o 1996 Wiley-Liss, Inc.

Stillbirths in Macaca fascicularis

“…The Tsukuba Primate Center for Medical Science reported the stillbirth rate in M. fascicularis at 8.9% [5]. Hendrie et al [12] reported the prenatal loss in M. fascicularis, including abortion and stillbirth, for a 10-year breeding period in a indoor time-mated colony at the California Regional Primate Research Center as 17.8%. Dukelow [6] described the stillbirth rate in the rhesus monkey (Macaca mulatta) as 10.6% in wildborn and 5.7% in colony-born monkeys.…”

“…Other authors defined stillbirths as all pregnancy outcomes other than live births, including abortion and fetal death of undetermined etiology [9]. Retrospective data on the frequency of prenatal loss in M. fascicularis showed the rate of stillbirths increases during late gestation (>150 dG) [12].…”

Chronic Administration of Tenofovir to Rhesus Macaques from Infancy through Adulthood and Pregnancy: Summary of Pharmacokinetics and Biological and Virological Effects

“…At the age of 10 years, a sixth pregnancy, fathered again by animal 31121, resulted in a healthy male infant that was delivered by cesarean section (due to a partial placenta previa) on estimated gestational day 152. As a comparison, the rate of prenatal mortality in rhesus macaques at the CNPRC is 17% (with the highest rate of loss during early gestation [gestational days 18 to 70]) (31), and therefore the loss of pregnancy in this animal was not deemed to be TFV related. Four pharmacokinetic studies that were performed on animal 31122 between the ages of 3 and 9 years indicate that during these consecutive pregnancies, maternal exposure to TFV (plasma AUCs) ranged from 6 to 19 g ⅐ h/ml (Table 1; Fig.…”

Advantages and Limitations of Commonly Used Nonhuman Primate Species in Research and Development of Biopharmaceuticals

“…Unexpectedly, treated maternal animals experienced a longer pregnancy than controls (up to a mean of 10 days) and a higher incidence of retained placenta, and prenatal maternal mortality associated in some cases with genital hemorrhages was observed. Dystocia is one of the leading causes of late pregnancy loss in cynomolgus monkeys, rhesus monkeys, and baboons, often resulting in intracranial trauma/hemorrhages in the nonviable fetus/infant [33][34][35]. However, difficult delivery rarely results in maternal death and is not usually associated with important genital blood losses, even in the case of placental retention.…”