Prevalence of pre-eclampsia and adverse pregnancy outcomes in women with
pre-existing cardiomyopathy: a multi-centre retrospective cohort study.
Abstract
Objective: To determine the prevalence of pre-eclampsia and fetal growth
restriction (FGR; <3rd centile) in women with pre-existing
cardiac dysfunction. Design: Retrospective cohort study. Setting:
Maternity units in UK and Australia. Population: Pregnant women with
impaired left ventricular ejection fraction<55%. Methods:
Routine clinical data, including medical history and pregnancy outcome
were collected retrospectively. Main Outcome Measures: Pre-specified
outcomes included pre-eclampsia and FGR prevalence in women with
pre-existing cardiac impairment, compared with the general population;
and the relationship between pregnancy outcome and pre-pregnancy cardiac
phenotype. Results: In this cohort of 282 pregnancies, pre-eclampsia
prevalence was not significantly increased (4.6% [95% C.I
2.2-7.0%] versus population prevalence of 4.6% [95% C.I.
2.7-8.2], p=0.99); 12/13 of these women had additional
obstetric/medical risk factors. However, prevalences of preterm
pre-eclampsia (<37 weeks) and FGR were increased (1.8% versus
0.7%, p=0.03; 15.2% versus 5.5%, p<0.001, respectively).
Neither systolic nor diastolic function correlated with pregnancy
outcome; however, left ventricular mass index (LVMi) weakly correlated
with pre-eclampsia (5g/m2 increase: OR 1.18 [95% C.I. 1.01-1.38],
p=0.04). Antenatal ß blockers (n=116) were associated with lower
birthweight Z score (adjusted difference -0.33 [95% C.I. -0.63-
-0.02], p=0.04). Conclusions: This study demonstrated a modest
increase in preterm pre-eclampsia and significant increase in FGR in
women with cardiac dysfunction. These results do not support a causal
relationship between cardiac dysfunction and pre-eclampsia, especially
accounting for the background risk status of the population. The
mechanism underpinning the relationship between cardiac dysfunction and
FGR merits further research but could be influenced by concomitant ß
blocker use.