Serial ultrasonographic measurements of fetal parameters over three successive pregnancies in a captive Eastern black-and-white colobus monkey (Colobus guereza).

This study provides ultrasonographic fetal growth charts for the Eastern black-and-white colobus monkey (Colobus guereza). Throughout three consecutive gestations (-162 to -2 days to parturition) in a single dam, we opportunistically obtained ultrasonographic measurements for the following parameters: biparietal diameter, head circumference, humerus length, femur length, tibia length, radius length, thoracic width, kidney length, and crown-rump length. Biparietal diameter was the most consistently measured parameter. First detection of fetuses occurred between 96 and 162 days before parturition. This report demonstrates that voluntary transabdominal ultrasound can be well-tolerated in the colobus monkey using operant conditioning. These findings may be useful to assess fetal development and predict parturition dates in the absence of a known conception date in this species.