DefinePK

Abstract

Background: Amniotic fluid plays a critical role in fetal development by maintaining a stable environment for growth, cushioning the fetus, and serving as a marker for maternal-fetal health. Oligohydramnios, defined as a reduced volume of amniotic fluid, is associated with adverse pregnancy outcomes and can result from placental insufficiency, fetal anomalies, or maternal conditions. Early detection through Doppler ultrasonography may assist in identifying circulatory changes indicative of this condition and allow timely clinical interventions.
Objective: To evaluate hemodynamic changes in the maternal renal artery in pregnancies complicated by oligohydramnios based on Doppler indices and compare them with normal pregnancies.
Methods: This cross-sectional study was conducted at Gillani Ultrasound Center, Pakistan, including 50 pregnant women selected via convenience sampling. Participants with diabetes, hypertension, critical illness, or fetal congenital anomalies were excluded. Oligohydramnios was defined by an amniotic fluid index (AFI) <5 cm, a single vertical pocket <2 cm, or an AFI below the 10th percentile for gestational age. Doppler ultrasonography was performed using a Toshiba Xario S100 with a 5–7 MHz convex probe to measure Resistive Index (RI), Pulsatility Index (PI), and Systolic/Diastolic (S/D) ratio of the renal artery. Data were analyzed using SPSS version 27.0, and independent samples t-tests were applied.
Results: Renal artery Doppler indices showed statistically significant differences between the normal and oligohydramnios groups. Mean RI was higher in oligohydramnios (0.625 ± 0.111) compared to normal pregnancies (0.575 ± 0.111). Similarly, PI was elevated in the oligohydramnios group (1.475 ± 0.111) versus normal (1.200 ± 0.111). The S/D ratio was also increased (2.975 ± 0.111 vs. 2.500 ± 0.111). All differences were statistically significant (p < 0.05).
Conclusion: Significant alterations in renal artery Doppler indices in oligohydramnios reflect impaired maternal hemodynamics, emphasizing the diagnostic value of Doppler ultrasonography in monitoring high-risk pregnancies.