Villous structure in different parts of the cotyledon in placentas of insulin-dependent diabetic women. A morphometric study.

Placentas from 13 insulin-dependent diabetic mothers and 10 non-diabetics were compared by means of photographic planimetry. The material was investigated in fresh state and obtained from three well-defined areas within a cotyledon, central, intermediate and lateral regions. Length and area of the villi in each region were calculated. The non-diabetics showed a consistent organization of the cotyledon, with increasing villous length towards the periphery. The surface areas increased with increasing length. In placentas of diabetic mothers, this organization was disrupted. The villi were of even length throughout the cotyledon. The average length of a villus in the diabetic group did not differ from the average length in the control group. Despite this fact, the average surface area in the diabetic was greater than that in the controls. This increased surface area was due to increased branching of peripheral villi in the diabetic group. The degree of blood glucose control of the diabetic mothers was assessed by the day-to-day variation in maternal blood glucose levels ( MODD ) for periods 12th to 32nd week and 32nd week to term and by "pregnancy glucose value", i.e. the mean of four consecutive daily blood glucose levels from the 32nd week of gestation to term. Only MODD values based on blood glucose values from 12th to 32nd week of gestation were correlated to the villous surface area. The greater the blood glucose variability, the greater was the surface area.