Hydronephrosis during pregnancy: how to make a decision about the time of intervention?

To evaluate the role of doppler ultrasonographorin managing hydronephrosis during pregnancy.

The study included 27 pregnant patients with unilateral symptomatic persistent hydronephrosis (group 1) and 38 pregnant patients with physiological hydronephrosis of pregnancy (group 2). All pregnant patients underwent Doppler Ultrasonography to determine the Resistive Index (RI) and the difference between the RI of the corresponding and contralateral kidney (Delta Resistive Index = delta RI).

There were no statistical differences between the two groups in terms of age, mean gestational period, or number of pregnancies. The mean renal RI of the hydronephrosis side was 0.68 ± 0.05 in group 1 and 0.60 ± 0.05 in group 2 (p less than 0.001). The mean delta RI of group 1 was significantly higher than the mean delta RI of group 2 (0.07 ± 0.03 versus 0.02 ± 0.01, respectively, p less than 0.001). The RI and delta RI were considered positive with values of more than 0.70 and more than 0.04, respectively, and the RI was sensitive in 44.4% and specific in 92.1% for intervention treatment. The corresponding values for delta RI were 88.9% and 89.5%. The positive predictive value and negative predictive value of delta RI for intervention were 85.7% and 91.9%, respectively.

It is much better to consider delta RI than RI when deciding on interventional treatment in hydronephrosis during pregnancy.