Objective

All women with CHD, especially those with more severe disease, should be offered preconception counseling (PCC), to discuss the risk of complications and to plan a future pregnancy. Several scoring system have been devised to estimate the risk of adverse events in pregnancies complicated by maternal heart disease (HD) and while comparisons have been made across the whole population, none have focused on the high-risk population.
Methods

Retrospective cohort study that included women classed as modified WHO (mWHO) 3 and 4 who had a pregnancy from at least 20 weeks gestation between 1994 and 2015 managed within our institution. We assessed how well the quoted risk (at PCC) of an adverse event (maternal or fetal) related to the actual rate of occurrence. We calculated NYHA and CARPREG scores for all patients, and the clinician assessment of percentage risk, to predict the occurrence of an adverse outcome.
Results
We identified 76 mWHO 3 and 4 women who had a total of 102 pregnancies. However, only in 63 pregnancies had the woman attended PCC. Both maternal and fetal adverse events were common. NYHA did not significantly predict any adverse events, whilst a CARPREG score of > 3 score predicted heart failure and mWHO4 score predicted maternal death. However, the best prediction of adverse outcomes was a composite quoted risk (percent) given at PCC.
Conclusions

Women must have access to PCC as those with worse CARPREG and mWHO scores encounter greater adverse events.