Fetal ultrasonography: biometric data from four African primate species.

Background  Nonhuman primates are raised in large numbers in research centers and zoos. Reproductive monitoring is required to improve breeding performances. Ultrasonography is a safe method to determine gestational age and to estimate the date of parturition. However only few data are available in nonhuman primates. Methods Fetal biometric data were obtained throughout pregnancy on four African primate species, namely chimpanzee, gorilla, mandrill and patas monkey. Measurements included biparietal diameter, transverse abdominal diameter, femur and humerus length, external interorbital diameter, and fetal heart rate. Curves established from these data were compared with previously published data in chimpanzees and gorillas and with those for humans and other closely related primate species. Results The curves for the different hominids were very similar, while those for mandrills more closely resembled baboons and data for patas monkeys were comparable to those for macaques. Conclusions These data, by providing a tool to evaluate precise gestational age, will be useful for centers raising these four primate species.