Maternal cardiovascular profile is altered in the preclinical phase of normotensive early and late intrauterine growth restriction

Abstract

BackgroundMaternal cardiovascular profile of patients developing late fetal growth restriction is yet to be well characterized, although a subclinical impairment of maternal hemodynamics and cardiac function may be present before pregnancy, becoming evident because of the hemodynamic alterations of pregnancy. ObjectivesOur objective was to investigate if maternal hemodynamics and the cardiovascular profile might be different in the preclinical stages (22-24 weeks gestation) of early and late fetal growth restriction in normotensive patients. Study designThis was a prospective echocardiographic study of 1152 normotensive nulliparous pregnant women at 22-24 weeks’ gestation. The echocardiographic evaluation included morphological parameters (left ventricular mass index and relative wall thickness, left atrial volume index) as well as systolic and diastolic maternal left ventricular function (ejection fraction, left ventricular LV global longitudinal strain, E/A, and E/e'). Patients were followed until the end of pregnancy to note the development of normotensive early or late fetal growth restriction. Results1049 patients had no complications, 73 were classified as late fetal growth restriction and 30 as early fetal growth restriction. Left Ventricular MorphologyLeft ventricular end-diastolic diameter was greater in uneventful pregnancies (4.84±0.28 cm) vs late (4.67±0.26 cm) and vs early fetal growth restriction (4.55±0.26 cm) (p<0.001), whereas left ventricular end-systolic diameter was smaller in uneventful pregnancies (2.66±0.39 cm) vs late (2.83±0.40 cm) and early fetal growth restriction (2.82±0.38 cm) (p<0.001). Relative wall thickness was slightly higher in early (0.34±0.05) and late fetal growth restriction (0.35±0.04) vs uneventful pregnancies (0.32±0.05) (p<0.05). Systolic Left Ventricular FunctionAt 22-24 weeks’ cardiac output was higher in uneventful pregnancies (6.58±1.07 L/min) vs late (5.40±0.97 L/min) and vs early fetal growth restriction (4.76±1.05 L/min) (p<0.001), with the lowest values in the early onset group. Left ventricular global longitudinal strain was lower in AGA (-21.6±2.0%), and progressively higher in late (-20.1±2.2%) and early fetal growth restriction (-18.5±2.3%) (p<0.001). Diastolic Left Ventricular FunctionE/e’ ratio showed intermediate values in the late fetal growth restriction (7.90±2.73) vs AGA (7.24±2.43) and vs early fetal growth restriction (10.76±3.25) (p<0.001). Total Peripheral Vascular ResistanceTotal Peripheral Vascular Resistance was also intermediate in the late fetal growth restriction (1300±199 dyne·s·cm-5) vs AGA (993±175 dyne·s·cm-5) and vs early fetal growth restriction (1488±255 dyne·s·cm-5) (p<0.001). ConclusionsEarly and late fetal growth restriction share similar maternal hemodynamic and cardiovascular profiles with a different degree of expression. These features are already present at 22-24 weeks gestation and are characterized by a hypodynamic state. The degree of these cardiovascular changes may influence the timing of the manifestation of the disease: a hypovolemic, high resistance, low cardiac output state might be associated to early onset fetal growth restriction, whereas a milder hypovolemic state seems to favor a development of the disease in the final stages of pregnancy.