Changes in kidney volume during pregnancy in non-diabetic and diabetic rats measured by magnetic resonance imaging

Consecutive magnetic resonance images were obtained in pregnant animals and their respective controls, and changes in kidney, cortex, medulla, and pelvis volumes were calculated. In non-diabetic pregnant animals, a marked increase in kidney and cortex volumes was observed within the first 15 days of pregnancy (29 and 20%, respectively), while no significant changes were seen in medulla or pelvic volumes. Five days later (near term) and after delivery, kidney and cortex volumes had decreased to values before pregnancy. In pregnant diabetic animals, a 26% increase in renal volume was seen over the first 15 days of pregnancy when compared to the increase seen in non-diabetic pregnant animals. Pregnant diabetic animals had a parallel increase in cortex and medulla volumes, but still no changes in the pelvis volume. In contrast to non-diabetic pregnant animals a non-heterogeneous pattern in renal volume was seen post partum, as not all animals normalized their renal volume.