Application of clinical indices of fetal growth and wellbeing to a novel laboratory species, the spiny mouse

Ultrasound was used to measure growth of the spiny mouse fetus throughout gestation and to record Doppler measurements of heart rate and umbilical blood flow to monitor fetal blood supply and wellbeing. Female spiny mice were anesthetized on 6 occasions throughout pregnancy. Ultrasound was performed with a Philips HDI 5000 machine using a compact linear CL15-7 transducer. Fetal heart rate and growth parameters increased across gestation. Blood flow through the umbilical artery and vein showed increasing velocity over gestation, and reduced resistance index. Blood flow through the ductus venosus also increased in velocity over gestation; however the resistance index remained constant. We have determined changes in umbilical blood flow throughout pregnancy in the spiny mouse, which resemble those seen in human pregnancy. We also confirm that ultrasound can be used as a valuable, non-invasive technique for measuring fetal growth and wellbeing in the spiny mouse.