Peripheral microcirculation during pregnancy and in women with pregnancy induced hypertension

During pregnancy the cardiovascular system undergoes several changes so as to adapt the maternal organism to the strains of pregnancy. These adaptatio ns can assume a pathological development in persons with a previous history of cardiovascular problems. On the other hand the absence of these adaptat ions may lead to a pathological course of pregnancy. Pregnancy induced hype rtension (PIH) may be such a pathological development due to maladaptation. The causes are for the most part unknown. For some time it has been assume d that it is due to microcirculatory disorders. Using periungual capillary microscopy the present study prospectively investigated the changes in peri pheral microcirculation during pregnancy focusing on pregnancy induced hype rtension. Sixty-seven women with a normal course of pregnancy and 28 women with pregnancy induced hypertension were evaluated. Throughout the prospect ive study 3 examinations were performed during pregnancy and one during chi ldbed. The women who developed a PIH were registered during the third trime ster. Erythrocyte velocity at rest and vascular reagibility of capillaries following a 3 minute ischaemia were evaluated. In the course of pregnancy a significant increase of approximately 30% in erythrocyte velocity could be observed. Interpolation to obtain the best strait line result demonstrates that it is a continuous increase. Erythrocyte velocity returns to normal i n the course of 14 weeks post partum. Due to a physiological vasodilatation during pregnancy, vascular reaction to ischaemic stress significantly decr eases. During childbed these changes return to normal. Examinations on wome n with pregnancy induced hypertension not only showed a significant reducti on of microcirculation under resting conditions but also a different patter n of reaction to ischaemic stress. Erythrocyte velocity under resting condi tions lies 36% below normal values. Furthermore the distinctly shortened hy peraemic period indicates a hightened sensitivity to vasoconstrictive subst ances in women with PIH. While taking into account the clinical data a posi tive correlation with the severity of the illness was able to be establishe d.