Abstract:
The feasibility of obtaining fetal blood samples by needle aspiration under ultrasound guidance was assessed in 32 fetal sheep from 101-1 36 days' gestation. Seventy-six attempts at blood sampling were made, of which all but two were successful. The overall fetal death rate resulting from this procedure was 9.2%. However, with increasing operator experience and with advancing gestational age, 95.5% of fetuses survived the procedure. Repeated sampling from individual fetuses had minimal effects on arterial blood gas values. Ultrasound guided blood sampling now provides an alternative to chronic catheterization as a basis for some types of research with fetal sheep.