Fetal Blood Sampling During the Second and Third Trimester in Baboons

The primate model continues to be an essential component of clinical research. The baboons (Papio cynocephalus) have been of particular interest due to their similarities with human placentation and fetal development.1 Fetal blood sampling allows the investigator to assess fetal condition at a specific point in gestation as well as transplacental transfer of medications or markers of interest. A method for fetal sampling in the pregnant macaque using fetoscopy was described by Davidson et al.2 in 1978 and by Morris et al.3 in 1980 for baboons. Hankins et al.4 described arterial blood sampling at 170 days gestation in pregnant baboons. Since fetal instrumentation in this species is associated with high rate of pregnancy loss2, it is essential for pregnancy related studies conducted in the baboon model to be able to develop the techniques of multiple sampling from fetal circulation. In humans, the procedure of cordocentesis was established in 19835 and allows for fetal blood sampling as early as 17 weeks gestation. It is often performed during the 18th–20th weeks of gestation with a complication rate of less than 1% with experienced surgeons. The objectives of this paper are to describe the detailed technique of ultrasound guided cordocentesis (UGC) in baboons at different gestational ages, report the maternal and newborn outcomes post-procedure, and review the existing publications and discuss advantages and disadvantages of each of them.