The impact of maternal plasma volume expansion and antihypertensive treatment with intravenous dihydralazine on fetal and maternal hemodynamics during pre-eclampsia: a clinical, echo-Doppler and viscometric study.
OBJECTIVE
To establish the effects of plasma volume expansion (PVE) followed by intravenous dihydralazine (DH) administration on maternal whole blood viscosity (WBV) and hematocrit, uteroplacental and fetoplacental downstream impedance and umbilical venous (UV) volume flow in pre-eclampsia.


METHODS
In 13 pre-eclamptic women maternal and fetal hemodynamics were established by means of combined measurement of maternal arterial blood pressure (BP), WBV, hematocrit and uterine artery (UtA) resistance index (RI) in addition to umbilical artery (UA) pulsatility index (PI) and UV volume flow obtained from UV vessel area and UV time-averaged flow velocity. In each woman all parameters were measured four times at baseline, after PVE, after DH and 24 h after the start of treatment.


RESULTS
Maternal diastolic BP, hematocrit and WBV display a significant reduction after PVE. In the fetus UA PI decreases significantly whereas a significant increase in UV cross-sectional area was detected. After maternal DH administration, arterial systolic and diastolic BP and UA PI show a significant decrease compared with the measurements following PVE. At 24 h, only maternal systolic and diastolic BP display a significant further decrease. No significant changes were established for the UtA RI, UV time-averaged velocity and UV volume flow during the entire study period.


CONCLUSIONS
During pre-eclampsia, maternal PVE followed by DH administration results in a significant reduction in maternal diastolic BP, maternal hematocrit and WBV. Maternal PVE is associated with a significant increase in UV cross-sectional area and a non-significant rise of 11% in UV volume flow. Maternal DH administration does not result in any change in UV cross-sectional area. However, UA PI decreases significantly after both PVE and DH treatment.
Boito
S M E
SM
Department of Obstetrics and Gynaecology, Erasmus Medical Centre, Rotterdam, The Netherlands.
Struijk
P C
PC
Pop
G A M
GA
Visser
W
W
Steegers
E A P
EA
Wladimiroff
J W
JW
D000959:Antihypertensive Agents / Q000627:therapeutic use*; D001794:Blood Pressure / Q000502:physiology; D004078:Dihydralazine / Q000627:therapeutic use*; D015150:Echocardiography, Doppler / Q000379:methods; D005260:Female; D005865:Gestational Age; D006400:Hematocrit; D006801:Humans; D021041:Placental Circulation / Q000502:physiology; D010953:Plasma Volume / Q000502:physiology*; D011225:Pre-Eclampsia / Q000188:drug therapy / Q000503:physiopathology / Q000628:therapy*; D011247:Pregnancy; D011673:Pulsatile Flow / Q000502:physiology; D014469:Umbilical Arteries / Q000503:physiopathology; D014471:Umbilical Veins / Q000503:physiopathology; D014655:Vascular Resistance / Q000502:physiology; D014783:Viscosity
D000959:Antihypertensive Agents; D004078:Dihydralazine