Introduction
Preeclampsia accompanies 2% of pregnancies, and is an important cause
of perinatal and maternal morbidity and mortality [1,2] .
Preeclampsia is diagnosed when novel onset of hypertension and
proteinurea or end-organ damage occurs after 20 weeks of gestation
[3] . Eclampsia is diagnosed after seizures without other etiologies
are observed in a preeclamptic pregnancy [4] .
In order to prevent seizure, magnesium sulfate prophylaxis is used as a
first-choice treatment. It prevents further seizures in eclampsia and
any future seizures in preeclampsia [5-7] . When compared with
placebo, magnesium sulfate decreases the risk of deterioration from
preeclampsia to eclampsia by 60% [8] . Besides prevention of
seizures, magnesium sulfate is a systemic vasodilator that elongates
sinoatrial impulse production and conduction period [9,10] . Given
the cardiovascular effects, magnesium sulfate may affect fetal cardiac
function [11] .
The myocardial performance index (MPI) was used by Tei et al in the
evaluation of cardiac functions in adult cardiomyopathy. Being a
non-invasive method derived from Doppler ultrasound, MPI is useful as a
global index of myocardial function. MPI is derived by dividing the sum
of the isovolumetric contraction time (ICT) and the isovolumetric
relaxation time (IRT) by the ejection time (ET) [12] . Tsutsumi et
al. were the first to use MPI to assess fetal cardiac function [13]
. Subsequently, Hernandez-Andrade et al. utilized aortic and mitral
valve closure and opening clicks on Doppler ultrasound and described the
modified MPI (Mod-MPI). This modification increased interobserver and
intraobserver reproducibility and reliability [14,15] .
There are studies that have investigated preeclampsia and fetal cardiac
function by MPI but they did not find any significant difference
[16,17]. However, there is no previous study that aimed to evaluate
the effect of magnesium sulfate prophylaxis used for prevention of
seizures in preeclamptic/eclamptic pregnant women on fetal cardiac
function. Therefore, this study was designed to assess the effect of
magnesium sulfate seizure prophylaxis on fetal cardiac function using
Mod-MPI.
Methods