Peripheral capillaroscopic findings and blood rheology during normal pregnancy.

Peripheral capillary microscopy and blood rheology where used to investigate circulatory changes during normal pregnancy. The first part of the investigation was designed as a cross-sectional study in which capillary morphology and blood flow in the first (n = 24) and third trimester (n = 15) of pregnancy was compared with non-pregnant controls (n = 15). In the second part a longitudinal comparison of capillaroscopic and hemorheological findings throughout pregnancy was performed in 12 women with four measurements at 10-week intervals. In addition, in this group hemorheological measurements were carried out. Both the cross-sectional as well as the longitudinal group showed a significant increase in capillary blood flow velocity which was already present in the first trimester. Throughout pregnancy a gradual enlargement of the pericapillar papilla was seen, reflecting water retention in the interstitial tissue. At low shear rates a significant increase in viscosity was found at the end of pregnancy both in whole blood and at a standardized hematocrit of 45%. Capillaroscopy appears to be an appropriate method to study circulatory changes throughout pregnancy and its value as a diagnostic tool to detect early pathological developments is the objective of a future investigation.