Maternal cardiovascular adaptation to pregnancy in obese pregnant women:
an observational longitudinal study
Abstract
Objective Obesity is known to be associated with cardiovascular
compromise and is a major risk factor for the development of
hypertensive disorders in pregnancy. The aim of this study was to
investigate the effect of obesity on the maternal cardiovascular system.
Design This was a prospective, observational, longitudinal study.
Setting A tertiary centre in London Population Pregnant women with
booking body mass index (BMI) ≥ 30kg/m2 (n=64) were compared to pregnant
women with normal booking BMI (20-24.9kg/m2) (n=14). Methods
Two-dimensional trans-thoracic echocardiography. Main outcomes
Longitudinal difference in blood pressure, cardiac geometry and cardiac
function between the groups. Results In women with obesity, the blood
pressure, heart rate and cardiac output were higher and peripheral
vascular resistance was lower (p<0.01 for all) compared to
normal BMI women. Women with obesity had altered cardiac geometry with
higher left ventricular end diastolic diameter, relative wall thickness
and left ventricular mass (p<0.001 for all comparisons). There
was also evidence of impaired diastolic indices in the obese group with
lower E/A ratio, TDI E’ lateral and medial and higher left atrial volume
(p<0.01 for all). Finally, women with obesity had reduced
longitudinal function between the second and third trimester of
pregnancy indicating possible early cardiac dysfunction in this group.
Conclusions Obesity is associated with maternal hyperdynamic
circulation, altered cardiac geometry and suboptimal diastolic function
compared to normal BMI pregnant women; this may contribute to the
increased risk of complications in obese pregnant women. Funding UK
charities: Borne and CW+