The effect of maternal Ramadan-type fasting (RTF) on the outcome of pregnancy, kidney development and nephron number in male rat offspring was investigated in current study. Pregnant rats were given food and water ad libitum during pregnancy (control) or restricted for 16 h per day (RTF). Kidney structure was examined during fetal life, at birth, and in early and late adulthood. Maternal body weight, food intake, relative food intake and plasma glucose levels were significantly lower (P<0.001) in the RTF group. Litter and pup weights also were significantly lower (P<0.05) in the RTF group at birth, with no difference in the litter size. The RTF group had a longer gestation, delayed nephrogenesis with less well-differentiated glomeruli, more connective tissue, fewer medullary rays, an increase in the nephrogenic zone/cortical zone ratio, and significant increase (P<0.001) in kidney apoptosis at birth. On the other hand, maternal fasting reduced nephron number (by ~31%) with unchanged kidney and total glomerular volumes. Mean glomerular volume was significantly higher in RTF offspring. Assessment of renal structure revealed mild glomerulosclerosis with enlarged lobulated glomeruli in the renal cortex and high interstitial fibrosis in the medulla of RTF kidneys. Taken together, gestational fasting delays nephrogenesis and reduces nephron number in the kidneys of the offspring, that could be partially owing to increased apoptosis.