Effects of Maternal Renal Dysfunction on Fetal Development

Maternal conditions affect the growth of the fetal kidney, which begins to secrete urine during late gestation (Bakala et al., 1985; Schaeverbeke & Cheignon, 1980). For example, during pregnancy, the maternal kidney undergoes various changes such as an increase in glomerular filtration rate (Baylis, 1994; Atherton & Pirie, 1981) and an alteration in tubular function (Dafnis & Sabatini, 1992). Furthermore, maternal undernutrition by the restriction of protein intake induces low fetal birth and leads to renal morphological and physiological changes (Mesquita et al., 2010). Maternal bilateral ligation of the uterine artery, protein restriction, smoking, nephrotoxic medication as well as salt loading cause intrauterine growth retardation (IUGR) to fetuses (Bentz & Amann, 2010), inducing fetal programing of renal function. Previously, we investigated the development of the fetal kidney during maternal renal dysfunction induced by bilateral ureteral ligation (Okada et al., 1997) and uninephrectomy (Okada et al., 2000, 2006), and we found that the development of the fetal kidney is accelerated by the operations. Furthermore, we found that maternal bilateral ureteral ligation (Okada & Morikawa, 1988) and uninephrectomy (Okada et al., 1998) decrease fetal body weight. In this chapter, we present a summary of the changes that occur in the fetal kidney after maternal bilateral ureteral ligation, uninephrectomy, and subtotal (5/6) nephrectomy, in addition to a summary of the changes that occur in the remaining kidney after uninephrectomy and 5/6 nephrectomy. Although 5/6 nephrectomy produces a bigger functional demand to maternal and fetal kidneys than the other two operations, little information is available on fetal development of the kidney when the maternal kidney is 5/6th removed. Therefore, we focused on studying the remaining kidney of unilateral and 5/6 nephrectomy and the fetal kidney under maternal renal dysfunction.