RELATIONSHIP OF BLOOD PRESSURE AND HEMORHEOLOGICAL FACTORS TO GESTATIONAL AGE IN NORMAL HUMAN PREGNANCY

Normal human pregnancy (PREG) predisposes towards gestational age (GA) based manifestation of atherogenic cardiovascular disease (CAD) risk 3. This study thus relates the dynamics of blood pressure (BP) and hemorheological (HH) factors, known CAD risk factors to GA in 50 normal pregnant human females at GA less than 20wk (PREG 20 wk) and GA 20wk and above (PREG 20wk). 25 apparently healthy non-pregnant (NO PREG) subjects served as Control. Systolic BP (SBP) and diastolic BP (DBP) were determined in sitting position with a mercury sphygmomanometer. Pulse pressure (PP) was calculated as SBP less DBP. Mean arterial pressure (MAP) was estimated as summed DPB and one third PP. Total plasma protein (TPP) concentration was determined enzynmatically. Levels of hematological variables were determined electronically. Relative plasma viscosity (RPv) and red blood cell (RBC) viscosity (RBv) were measured by simple needle and syringe type viscometry9. RBC deformability index (DI) was computed as quotient of corrected RBv and RPv10. Significant drop in SBP was noted early in PREG group compared with the control (p 0.05). At PREG 20wk, SBP increased towards control value. Similar trend was observed in DBP pattern. MAP was significantly (p 0.05) depressed in PREG commencing early in PREG (PREG 20 wk). No significant differences were noticed in hemoglobin concentrations of PREG and Control. Compared to Control, significant decreases were observed in values of hematocrit, platelet count and TPP concentrations of PREG groups (p 0.05). White blood cell (Wbc) count was significantly (p 0.05) elevated in PREG group compared to Control. PREG 20wk Wbc was significantly higher than PREG 20 wk (p 0.05). PREG 20wk RPv was significantly higher than Control or PREG 20 wk (p 0.05). Compared to Control, PREG 20wk RBv was significantly (p 0.05) lower than PREG 20 wk. Percent DI was similarly significantly (P 0.05) lower in PREG 20wk vis-a-vis PREG 20 wk or Control. These results potently suggest that the HH changes observed in this study are of advantage to the hyper-dynamic circulation of PREG. These changes in conjunction with falls in BP prevent the potential progression of normal PREGinduced CAD risk onto frank CAD