Vascular changes of endometrium in early pregnancy.

Spiral arteries, from curetted endometrium, of first-trimester pregnancies, were examined in 342 consecutive cases, comprising 150 primigravida and 192 multigravida . Vascular changes, similar to the "acute atherosis ," described at the end of pregnancy in preeclamptic women, were found. Primigravida had a statistically higher incidence of vascular changes than multigravida . The light microscopic changes were those of intimal proliferation with the presence of foam cells. These intimal cells were mostly myofibroblasts. Mucopolysaccharides also were found in the intima by both light microscopy and ultrastructural studies. The possible importance of the finding of vascular changes in spiral arteries in early pregnancy is discussed.