Uterine Artery Doppler Indices in the Second and Third Trimester in Women with Normal Singleton Pregnancy Uterine artery Doppler indices in normal pregnancy

Abstract

Background: The maternal mortality rate has declined since 1990 but many women still die from pregnancy-related causes and during childbirth, especially in developing countries like Nigeria. Doppler ultrasound has a non-invasive, accurate method of evaluating the uterine arteries and it reflects any changes in placental perfusion through the Doppler velocimetry. Objectives: To determine the pulsatility index (PI), resistivity index (RI), end-diastolic velocity (EDV), peak systolic velocity (PSV), and systolic/ diastolic ratio (S/D) of the right and left uterine arteries in the second and third trimesters of a normal singleton gestation. Materials and Methods: A study of 176 singleton pregnancies of patients 18yrs and above taken at 21-25 weeks and 31-35 weeks gestation for each patient. Blood pressure and urine protein were checked at each visit. Results: The right and left uterine arteries respectively in the second trimester; PI - 1.01+/-0.26, 1.03+/-0.27, RI - 0.598+/-0.07, 0.606+/-0.09, PSV - 88.33+/-44.70, 92.60+/-50.56, EDV - 38.46+/-22.01, 41.35+/-26.94, S/D - 2.43+/-0.58, 2.44+/-0.59. The right and left uterine arteries respectively in the third trimester; PI - 0.89+/-0.22, 0.88+/-0.21, RI - 0.55+/-0.07, 0.54+/-0.06, PSV - 106.69+/-57.66, 139.83+/-56.33, EDV - 50.14+/-23.91, 66.99+/-28.30, S/D - 2.15+/-0.49, 2.14+/-0.37. A statistically significant difference in the parameters from the second to the third trimester, an increase in the PSV and EDV value, and a decrease in the PI, RI, and S/D values. Conclusion: A valuable regional nomogram for singleton gestation has been established with which to compare Doppler indices values in high-risk pregnancies.