Effect of the loading dose of magnesium sulfate (MgSO4) on the parameters of Doppler flow velocity in the uterine, umbilical and middle cerebral arteries in severe preeclampsia.
OBJECTIVE
To evaluate Doppler velocimetry parameters (resistance index [RI], pulsatility index [PI] and systolic/diastolic [S/D] ratio) of maternal-fetal circulation before and after magnesium sulfate administration in pregnant women with severe preeclampsia.


METHODS
A prospective observational cohort analysis of 40 women with severe preeclampsia was performed. Doppler ultrasonography scans were performed before and 20 minutes after intravenous administration of magnesium sulfate. Maternal parameters such as heart rate, and systolic, diastolic and mean arterial pressure were recorded. Doppler flow velocity parameters (RI, PI and S/D ratio) were evaluated in the uterine, umbilical and middle cerebral arteries. The different mean values obtained before and after magnesium sulphate were analyzed using the paired t-test.


RESULTS
There was a statistically significant increase in mean maternal heart rate and a statistically significant decrease in systolic, diastolic and mean maternal blood pressure before and after administration of magnesium sulphate (p < 0.001). Resistance index decreased in the umbilical (p = 0.003; 95% CI: 0.008 - 0.03) and middle cerebral artery (p = 0.001; 95% CI: 0.01 - 0.05) and in both uterine arteries. Likewise, there was a significant reduction in the PI and S/D ratio in all the arteries assessed.


CONCLUSIONS
Maternal administration of intravenous magnesium sulfate in preeclampsia leads to an increase in maternal heart rate and a decrease in systolic, diastolic and mean arterial blood pressure. A reduction in the resistance index, pulsatility index and S/D ratio was recorded in the uterine, umbilical and cerebral arteries.
Souza
Alex Sandro Rolland
AS
Instituto de Medicina Integral Professor Fernando Figueira-IMIP, Recife, Brazil. alexrolland@uol.com.br
Amorim
Melania Maria Ramos
MM
Coutinho
Isabela Cristina A N C
IC
Lima
Marcelo Marques de Souza
MM
Noronha Neto
Carlos
C
Figueroa
José Natal
JN
D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000008:administration & dosage*; D001783:Blood Flow Velocity / Q000187:drug effects; D005260:Female; D006801:Humans; D008278:Magnesium Sulfate / Q000008:administration & dosage*; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000187:drug effects; D011225:Pre-Eclampsia / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D011247:Pregnancy; D011446:Prospective Studies; D016216:Ultrasonography, Prenatal; D014469:Umbilical Arteries / Q000000981:diagnostic imaging / Q000187:drug effects; D055988:Uterine Artery / Q000000981:diagnostic imaging / Q000187:drug effects; D055815:Young Adult
D000927:Anticonvulsants; D008278:Magnesium Sulfate