Changes in Doppler indices throughout pregnancy in queens

Melih Uçmak,Mehmet Can Gündüz,Zeynep Günay Uçmak,Ozge Turna,Gamze Evkuran Dal

doi:10.2754/avb202089010061

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.

Highlights

Doppler ultrasonography (D-USG) is a non-invasive technique that provides information about maternal and foetal haemodynamics in pregnancy (Fleischer et al 1994; Erdogan 2018)
A declining trend was seen in the mean resistance index (RI) of foetal aorta (FA), a comparison with earlier sampling periods revealed that significant decreases (P < 0.05) did not occur until Days 30 and 60
Despite the minimal use of foetal aorta Doppler findings in assessing foetal well-being, research indicates that the disappearance, reversal, or decrease in the end diastolic flow of the foetal aorta may be an indicator of progressive foetal hypoxia (Lees et al 2003)

Summary

Introduction

Doppler ultrasonography (D-USG) is a non-invasive technique that provides information about maternal and foetal haemodynamics in pregnancy (Fleischer et al 1994; Erdogan 2018). The haemodynamic characteristics of maternal and foetal vessels throughout pregnancy were previously reported in mares (Ouset et al 2012; Ferreira et al 2015), cows (Kelley et al 2017), ewes (Elmetwally et al 2016; Turna Yilmaz et al 2017), goats (Serin et al 2010), rabbits (Polisca et al 2010), bitches (Di Salvo et al 2006), and queens (Scotti et al 2008; Blanco et al 2014; Blanco et al 2016). Part of the increasing interest in the haemodynamic characteristics of different species in veterinary obstetrics, Doppler evaluation of maternal and foetal vessels in normal feline pregnancy was first described in 2008 by Scotti et al Doppler findings of impaired pregnancies were first reported by Turna et al (2014), based on findings. The aim of this study is to advance knowledge about Doppler findings for normal feline pregnancy

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Conclusion