Comparative evaluation of fetal renal artery hemodynamics in normohydramnios, idiopathic oligohydramnios and polyhydramnios in third trimester pregnancy

Objective

To compare the renal artery (RA) flow indices (RI and PI) among normohydramnios, idiopathic oligohydramnios, and polyhydramnios and determine applicability of fetal RA Doppler indices in predicting the pregnancy outcome.

Methods

Total 106 3rd trimester pregnant patients were divided into cases and controls based on amniotic fluid index. Routine antenatal and color Doppler (including kidneys) ultrasound was performed for all patients in this study. The postnatal follow-up was done, and the pregnancies having poor outcomes in terms of NICU admissions were assessed.

Results

Statistically significant differences were noted when comparing RI and PI values of normohydramnios (0.91 ± 0.04 and 2.38 ± 0.21, respectively) with oligohydramnios (1.02 ± 0.07 and 2.99 ± 0.38, respectively) and polyhydramnios (0.90 ± 0.12 and 2.7 ± 0.84, respectively) independently (p value < 0.05). Our study demonstrated an increase in NICU admissions in the fetus having raised values of RI and PI.

Conclusion

Fetal RA RI and PI can be used as an antenatal predictor for the pregnancy outcome associated with idiopathic oligohydramnios; however, fetal RA PI was found to be a better predictor for the pregnancy outcome than fetal RA RI value in our study.