Maternal hemodynamic assessment by USCOM^® device in the first trimester of pregnancy

Preeclampsia is a main obstetric disease and could be caused by the inability of the woman hemodynamic system to face the cardiovascular effort required by gestation.

The aim of the present study is to evaluate the correlation between maternal hemodynamic parameters detected by UltraSonic Cardiac Output Monitor (USCOM^®) and ultrasound or biochemical parameters in women during the first-trimester screening of chromosomal abnormalities.

This was a prospective observational study with 162 women enrolled during the first-trimester ultrasound, recording demographic, biochemical and ultrasound data, including the pulsatility index of uterine arteries (UTPI). Hemodynamic indices were obtained using the USCOM^® system. We also analyzed the outcomes of pregnancy of those women who delivered in our clinic.

As for the correlation between biochemical and ultrasound parameters, pregnancy-associated plasma protein A (PAPP-A) relates inversely with the mean UTPI (r_s -0.298, p < .001). We also reported a statistically significant correlation between the mean UTPI and the maternal haemodynamic parameters detected by USCOM^® (higher values of mean UTPI are associated with lower values of indexed cardiac output, CO, and higher indexed peripheral resistances, TVR). When comparing women with higher UTPI and TVR or lower CO to patients who had regular values of these parameters, we noticed that between these groups there were significant differences in all the remaining hemodynamic parameters, including inotropy index and stroke volume, as well as in the biochemical values of PAPP-A. Analyzing postpartum data, if we combine the onset of hypertensive disorders and fetal growth restriction, the most predictive parameter is indexed TVR.

Our study confirmed the correlation between PAPP-A and placental function, expressed through the determination of the pulsatility index of the uterine arteries. Moreover, we found a clear correlation between biochemical markers, placental function and maternal hemodynamics, since the first trimester of pregnancy. The inclusion of maternal hemodynamic evaluation could be useful in the screening protocols of preeclampsia. If we combine the onset of hypertensive disorders and of fetal growth restriction, the most predictive parameter is indexed total vascular resistances.