Reflux nephropathy and the risk of preeclampsia and of other adverse pregnancy-related outcomes: a systematic review and meta-analysis of case series and reports in the new millennium

J Nephrol. 2018 Dec;31(6):833-846. doi: 10.1007/s40620-018-0515-1. Epub 2018 Jul 31.


Background: Reflux nephropathy is a common urinary tract malformation, and a substantial cause of morbidity in women of childbearing age. While recent studies provide further new information on pregnancy-related outcomes, their results are heterogeneous and a systematic meta-analysis may help the interpretation. The aim of this review was to analyze pregnancy-related outcomes in the recent literature on reflux nephropathy (2000-2016), to perfect the estimation of risks, and to identify specific research needs.

Methods: We searched Medline, EMBASE and the Cochrane review databases for the period 2000-2016 (PROSPERO registration no. 42016042713).

Selection criteria: all case series and case reports dealing with reflux nephropathy and reporting on at least one pregnancy outcome. Data were extracted from eligible case series (≥ 6 cases). For the outcomes preeclampsia (PE), pregnancy-induced hypertension (PIH), preterm birth, and newborns small for gestational age, we employed as a control group the low-risk pregnancies from a multicenter database including 1418 live-born singletons. Case reports were analyzed narratively.

Results: The search retrieved 2507 papers, of which 7 case series and 4 case reports were retained. The series report on 434 women with 879 pregnancies; no study reported controls. Compared to the low-risk controls, the meta-analysis showed an increased risk of PIH (odds ratio, OR 5.55; confidence interval, CI 3.56-8.66), PE (OR 6.04; CI 2.41-15.13), and all hypertensive disorders combined (OR 10.43; CI 6.90-15.75). No difference was observed in preterm delivery and caesarean sections. A higher incidence of stillbirth was reported in one paper. Conversely, the 4 case reports (on 10 pregnancies) alert us to a potentially severe complication, hydro(uretero)nephrosis with or without infection.

Conclusion: Reflux nephropathy is associated with an increased risk of PIH and PE, but not of preterm delivery, suggesting the occurrence of late 'maternal' PE. The finding of a higher incidence of stillbirths in one series requires further analysis. Strict follow-up of these women is needed, in particular in late pregnancy stages, to avoid and manage in particular hypertensive pregnancy complications.

Keywords: CKD; Kidney scars; Preeclampsia; Pregnancy; Preterm delivery; Reflux nephropathy; Solitary kidney.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Blood Pressure
  • Female
  • Gestational Age
  • Humans
  • Infant, Newborn
  • Infant, Premature
  • Infant, Small for Gestational Age
  • Kidney / pathology
  • Kidney / physiopathology
  • Kidney Diseases / diagnosis
  • Kidney Diseases / epidemiology*
  • Kidney Diseases / physiopathology
  • Pre-Eclampsia / diagnosis
  • Pre-Eclampsia / epidemiology*
  • Pre-Eclampsia / physiopathology
  • Pregnancy
  • Pregnancy Outcome
  • Premature Birth / diagnosis
  • Premature Birth / epidemiology
  • Risk Assessment
  • Risk Factors
  • Stillbirth / epidemiology
  • Vesico-Ureteral Reflux / diagnosis
  • Vesico-Ureteral Reflux / epidemiology*
  • Vesico-Ureteral Reflux / physiopathology