Prevalence of maternal cardiac defects in women with high-resistance uterine artery Doppler indices.

OBJECTIVES

To compare the prevalence of previously undiagnosed cardiac structural abnormalities in pregnant women with normal- and high-resistance midtrimester uterine artery Doppler indices.

METHODS

Maternal transthoracic echocardiography was undertaken in asymptomatic pregnant women after uterine artery Doppler screening for pre-eclampsia at 21-23 weeks' gestation. Women with a mean uterine artery pulsatility index above the 90(th) centile (1.25) for the local population (multiethnic, socially diverse and migrant) were considered to have high-resistance uteroplacental blood flow indices. The prevalence of newly diagnosed cardiac structural defects in these women was recorded.

RESULTS

A total of 491 women underwent echocardiography, of whom 205 had high-resistance uterine artery blood flow indices. There were nine previously undiagnosed, functionally significant cardiac defects in the high-resistance uterine artery blood flow group and only one, functionally insignificant cardiac defect in the normal-resistance group (P = 0.005; relative risk = 12.6, 95% confidence interval, 1.60-98.34). Multiple regression analysis demonstrated that both uterine artery Doppler indices (P = 0.024) and ethnicity (P = 0.048) contributed independently towards a higher prevalence of cardiac defects.

CONCLUSIONS

The prevalence of previously undiagnosed maternal cardiac structural abnormalities is significantly increased in women with high midtrimester uterine artery Doppler resistance indices. This observation has important consequences for the current and long-term medical care provided to these patients. Detailed maternal cardiac assessment with echocardiography may be required in migrant women with high uterine artery Doppler indices.