The impact of obesity on haemodynamic profiles of pregnant women beyond 34weeks' gestation.

Abstract

We aimed to compare the haemodynamic profiles of obese and non-obese pregnant women, alongside describing the haemodynamic changes that occur in hypertensive disorders of pregnancies with an Appropriate for Gestational Age Fetus (HDP-AGA) beyond 34weeks' gestation. In this prospective case-control study, maternal haemodynamic assessment was carried out by a trained operator using an UltraSonic Cardiac Output Monitor during a routine clinical assessment after 34weeks of gestation. Indexed and non-indexed parameters were evaluated. Maternal hemodynamic parameters. Obese and non-obese women did not differ for non-indexed parameters (Cardiac Output, Stroke Volume, Systemic Vascular Resistance). Using indexed parameters, corrected for Body Surface Area, obese women presented significantly lower Cardiac Index z-score (-0.23±0.5 vs 0.26±1.2; p=0.004), Stroke Volume Index z-score (-0.27±0.8 vs 0.31±1.0; p<0.0001) and significantly higher Systemic Vascular Resistance Index (0.16±0.8 vs -0.36±0.7; p<0.0001). In obese women, HDP-AGA (n=19) had significantly higher Systemic Vascular Resistance Index z-score (1.26±1.7 vs 0.16±0.8; P=0.009) and significantly lower Stroke Volume Index (-0.68±0.8 vs -0.27±0.8; 0.049). Using indexed parameters, differences in haemodynamic profiles between obese and non obese women can be highlighted. Obese women seem to present a cardiac maladapation to the pregnancy (reduced cardiac index and stroke volume and increased vascular resistance) that could explain the increased risk of complications in this subgroup.