Factors predicting the need for surgical intervention for hydronephrosis during pregnancy: a systematic review of the literature

Symptomatic hydronephrosis in pregnancy can cause both maternal and obstetric complications. In various studies, factors predicting the need for surgical intervention have been evaluated, however these factors have not been systematically assessed yet. This systematic review analyzes published studies about hydronephrosis during pregnancy and determines the predictive factors for the need for surgical intervention for hydronephrosis during pregnancy. A systematic review was conducted in January 2023 using the Medline, Web of Science and ScienceDirect/Scopus databases according to PRISMA guidelines. We searched these databases with the following search strategy: (intervention OR nephrostomy OR stent insertion) AND (pregnancy hydronephrosis). The literature review revealed 2461 potentially eligible studies. After the screening, six studies were enrolled in this review. High neutrophil-to-lymphocyte ratio, high C-reactive protein level, high white blood cell count, high creatinine levels, fever, persistent pain for more than 4 days, presence of ureteral stones more than 8 mm, high grade hydronephrosis, high fetal body weight and high delta resistive index were reported to be related with the need for surgical intervention. The rate of symptomatic hydronephrosis and requirement for surgical intervention is low during pregnancy. However, as symptomatic hydronephrosis may cause serious obstetric complications, it is important to know the parameters that can predict patients who may need surgical intervention. These results will assist gynecologists and urologists to stratify pregnant women for surgical intervention.