Blood rheology at term in normal pregnancy and in patients with adverse outcome events

Plasma volume expansion of more than 1.5 l and sustainable activation of the hemostatic system that results in a steady rise of the fibrinogen/fibrin turnover are contemporary physiological events during normal pregnancy. In contrast, adverse outcome of pregnancy i.e. pre-eclampsia commonly coincide with hemo concentration and over activation of blood coagulation both of which alter blood rheology. On the basis of 4,985 consecutively recorded singleton pregnancies values range of blood rheological parameters in women with normal and complicated outcome of pregnancy at the time of their delivery were compared. Plasma viscosity (pv) was determined using KSPV 1 Fresenius and RBC aggregation (stasis: E0 and low shear: E1) using MA1-Aggregometer; Myrenne. Seventy-nine point four percent (n=3,959) had normal pregnancy outcome and 1,026 with adverse outcome of pregnancy had pre-eclampsia (8.4%; n=423), had newborn with a birth-weight < 2,500 g (9.5%; n=473), had early-birth before week 37 (9.3%; n=464), and/or were diagnosed with intra uterine growth retardation (IUGR) (5.0%; n=250). In women with normal pregnancy outcome mean (+/-SD) of pv was 1.31+/-0.09 mPa s, of E0 was 21.6+/-5.3, and of E1 was 38.4+/-7.9 while in women with adverse outcome means for rheological parameters were statistically significantly different i.e. pv: 1.32+/-0.08 mPa s; p=0.006, E0: 22.1+/-5.5; p=0.002 and E1: 39.5+/-8.5; p=0.0006. Subgroup analysis revealed statistical significant lower pv in women who either had pre term delivery or a low birth-weight child (p<0.005) as compared to women who had normal pregnancy outcome while patients with pre-eclampsia had markedly higher low shear and stasis RBC aggregation (p<0.0001). None of the rheological results at term were correlated with either maternal age (r<0.04), BMI (r<0.09), maternal weight gain until delivery (r<0.04), or fetal outcome such as APGAR-score (r<0.09) art. pH in the umbilical cord (-0.05