Relationship between Maternal Hydronephrosis and Estimated Foetal Weight in Bayelsa State, South-South Nigeria

Abstract

Background: Hydronephrosis is the dilatation of the renal calyces and pelvises by urine, as a result of obstruction of the outflow of urine distal to the renal pelvis. It is a common finding in normal pregnancy, and usually physiological. Objective: To determine the relationship between maternal hydronephrosis and estimated foetal weight in normal pregnancy. Materials and Methods: This was a prospective study that was carried out at the Obstetric Units and Radiology Departments of the Federal Medical Centre, Yenagoa and the Niger Delta University Teaching Hospital, Okolobiri, both in Bayelsa State, Nigeria, for over six months. Sonographic evaluation of the renal pelvises and calyces of 400 normal pregnant women were performed and compared with estimated foetal weights. Relevant data were entered into a pre-designed proforma and analysed. Spearman’s correlation coefficient was used to determine the relationship between maternal hydronephrosis and estimated foetal weight. Results: Of the four hundred pregnant women enrolled in this study, about 36% had hydronephrosis (27% with Grade 1 and 9% with Grade 2). While gestational age (ρ = 0.22; p – 0.001) and estimated foetal weight (ρ = 0.26; p – 0.001) were significantly related to hydronephrosis, maternal features including maternal age (ρ = 0.05; p – 0.523), maternal weight (ρ = 0.01; p – 0.935) and parity (ρ = 0.06; p – 0.368) were not. Conclusion: Our study revealed that there was a relationship between maternal hydronephrosis and estimated foetal weight in normal pregnancy. The degree of pelvicalyceal dilatation also increased with gestational age.