Letters to the Editor
Towards Safer Pregnancies in Women With Congenital Heart Disease – Reply –
2015 Volume 79 Issue 9 Pages 2076-2077
Details
2015 Volume 79 Issue 9 Pages 2076-2077
We thank Dr Balci and colleagues for their comments concerning the importance of external validation for the risk estimation models of pregnancy in women with congenital heart disease (CHD).1 Since our study was accomplished before the publication of the study by Balci et al,2 we wrongly stated that our work was the first study to compare the performance of 3 risk estimation methods for predicting maternal cardiac risk of pregnancy in patients with CHD. We apologize for missing this important study before submission of our paper.
We noticed that the definitions of significant left heart obstruction are different in the CARPREG index and ZAHARA score.3,4 The pressure gradient of significant left heart outflow obstruction is >30 mmHg in the CARPREG index and >50 mmHg in the ZAHARA score. So we calculated these scores according to their own definitions.
In contrast to the prospective study by Balci et al, our retrospective study provides a different aspect of validation. In our series, many patients didn’t receive proper prepregnancy counseling in the early years of our retrospective study. Therefore, our study included more patients (13%) in modified WHO class IV, which is regarded as a contraindication for pregnancy.1 In contrast, only 0.9% of patients in the prospective study by Balci et al were in modified WHO class IV. So our study may be helpful in comparing the predictive performances of these 3 risk estimation methods for maternal cardiac complications in pregnant women with more severe cardiac conditions.
Base on the results of our work and that of several recent studies,1,2,5–7 we believe the modified WHO classification has the better performance in predicting maternal cardiac risks in women with CHD. So we developed a flow chart of prepregnancy counseling according to risk stratification by modified WHO classification for our clinical practice (Figure).
Flowchart for preconception assessment and counseling for women with congenital heart disease. CPX, cardiopulmonary exercise test; PE, physical examinations; WHO, World Health Organization.
The cardiologist should explain sufficiently to the patient the estimated maternal and fetal risks, and arrange an individualized multi-disciplinary approach for future pregnancy.
1. If the patient has any correctable risk factors for maternal or fetal complications (eg, left heart obstruction, cyanosis, arrhythmias), cardiac interventions for risk reduction should be performed before conception as possible to minimize the maternal and fetal events and to avoid the high risk of invasive intervention during pregnancy.
2. Current medications should be reassessed for possible harmful effects on the fetus during pregnancy. The cardiologist must discuss with the patient the benefits and risks of medication adjustment for the mother as well as the fetus.
3. When the patient possesses any uncorrectable risk factors that are contraindicated for pregnancy, it is exceedingly important for a consulting specialist to recommend an effective contraception method to prevent high-risk pregnancy.
4. Genetic specialist counseling and recurrent risk estimation should be provided to all adults with CHD, regardless of sex or severity of the cardiac condition. It is essential to obtain a detailed family history to pinpoint possibly affected members and identify possible dysmorphic clues related to associated syndromes.
5. For women with higher risks for pregnancy, multidisciplinary teams specializing in adult CHD management, including adult CHD specialist, obstetrician, anesthetist, genetic specialist and cardiac surgeon, should be available if necessary to provide optimal care during pregnancy.
(Released online August 7, 2015)
