Changes in Renal Volume During Normal Pregnancy

Twenty-four healthy pregnant women with a normal pregnancy demonstrated a significant uniform enlargement of both kidneys. The renal volumes increased by a maximum of 30% during pregnancy. However, this could not be attributed to hydronephrosis, as the patients were selected in such a way that none with pelvectasia participated in the study. All regained normal renal volume within the first week after delivery. It is well known that a glomerular hyperfiltration takes place during normal pregnancy. Possible pathogenetic mechanisms are discussed.