Hardee I, Wright L, McCracken C, Lawson E, Oster ME.J Am Heart Assoc. 2021 Apr 20;10(8):e017834. doi: 10.1161/JAHA.120.017834. Epub 2021 Apr 6.PMID: 33821681
Take Home Points:
- More severe congenital disease was associated with neonatal mortality.
Commentary by Dr. Helen Parry (Leeds, UK), section editor of ACHD Journal Watch:
Introduction: Survival to reproductive age in infants with congenital heart disease is higher than ever before. Counseling these patients regarding risk of pregnancy and management throughout the gestational and postpartum period can be challenging as the evidence base is relatively small.
Objective: To group data from previously published studies to assess risk of maternal or fetal death according to severity of congenital heart Disease
Methods: Studies analyzed were published between 2007 and 2019 and identified from the MEDLINE, EMBASE and Cochrane libraries. Only studies reporting on maternal or fetal mortality with data of the severity of the congenital cardiac lesion were included. Many different study types were included including cohort studies, cross-section studies, randomized trials and case series.
Congenital cardiac conditions were categorized into 3 groups for the purpose of analysis:
- Mild: ASD, VSD, PDA
- Moderate: coarctation, Ebstein’s anomaly, pulmonary stenosis and Tetralogy of Fallot
- Severe: double outlet right ventricle, Fontan, pulmonary atresia, transposed great arteries, Eisenmenger syndrome
Statistical analysis was performed using Comprehensive Meta-Analysis v3. Data were summarized according to the total number of patients, total number of events and the event rate. Event rates were given by percentages with 95% Confidence Intervals by random effects regression.
Two methods were used to assess the robustness of the study:
- Data were reclassified as mild, moderate and severe according to the method published by Stout et al, the analysis was repeated
- Analyses were repeated removing single studies, if the result then fell outside the 95% confidence interval the results were regarded as biased by that single study
Thirty-two studies were included, 27 of those looked at maternal mortality. There were 9 maternal deaths in total, all due to “uncontrollable heart failure”. Eight of these 9 women had lesions classed as severe. Sub-analysis of specific lesions demonstrated mortality was highest in patients with Eisenmenger syndrome (13%) and transposition of the great arteries (1%).
Sub-categories were analyzed as summarized in the table below:
|Complication||Event rate mild %||Event rate moderate %||Event rate severe %|
|Miscarriage/ spontaneous abortion||Too few for accuracy||16||34|
|Small for gestational age||15||14||36|
Too few studies looked at therapeutic abortion for the data to be included. Overall recurrence rate (i.e. babies with congenital heart disease born to mothers with congenital heart disease) was 33 in 1075.
Conclusions: The most firm conclusion drawn by the authors is the association between more severe congenial heart disease and neonatal mortality.
Positive aspects of the study:
- Data generated can help when counseling women as a broad guide
- Highlights gaps in the existing literature such as the frequency of therapeutic abortion in women with congenital heart disease
- Adds to what is a relatively small pool of data in a rapidly growing area of medicine
- The authors acknowledge that there was heterogeneity in how certain complications were defined across studies; this was most striking in arrhythmia
- Many different study designs were used making comparison between studies/ pooling of data less reliable
- Grouping of disorders as mild, moderate and severe could be criticized, especially since transposition of the great arteries was classed as severe. Some post arterial switch patients are likely to be thought of lower risk than some patients with tetralogy of Fallot repair who have developed multiple complications
- It is unclear whether the associations with congenital heart disease and some of the sub-group outcomes, such as prematurity, are controlled for other factors that influence prematurity
- Certain diagnoses which are commonly encountered and produce significant concern in pregnancy do not specifically appear such as bicuspid aortic valve aortopathy (which may not be coarctation) and Marfan’s syndrome.