Changes in Doppler indices throughout pregnancy in queens

Abstract

Doppler ultrasonography (D-USG) is a non-invasive technique that has become an increasingly essential tool in veterinary theriogenology. The aim of this study was to evaluate the changes of Doppler indices in the foetal aorta (FA), foetal vena cava (FVC), umbilical artery (UA), and uteroplacental artery (UPA) in pregnant queens, thereby advancing knowledge about Doppler findings in normal feline pregnancy. The study was conducted with 10 pregnant queens with known gestational age. Doppler ultrasonography was performed every three days beginning from the 21st day to the 60th day of pregnancy. The pulsatility index (PI) and resistance index (RI) of FA, FVC, UA and UPA were recorded during the D-USG examinations. Although a declining trend was seen in the mean RI of FA, a comparison with earlier sampling periods revealed that significant decreases (P < 0.05) did not occur until Days 30 and 60. While PI of FVC was relatively constant, RI varied througout pregnancy. The PI and RI of UPA values were significantly lower (P < 0.05) on Day 60 when compared to the first five sampling periods for PI and the first six sampling periods for RI. The study concludes that the decrease in UA indices is a precursor for delivery time in queens. However, there is a need for further comparative studies involving impaired pregnancies.