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Page 4 of 17 Saxena et al. Vessel Plus 2022;6:15 https://dx.doi.org/10.20517/2574-1209.2021.96

Figure 1. Hemodynamic changes during (A) pregnancy and (B) labor.

Most cardiovascular parameters return to preconception values within two weeks. The stroke volume,
cardiac output, and heart size take a longer time and reach preconception levels by 3-6 months. In patients
with CHD, cardiovascular maladaptation can persist even six months after delivery . The critical periods
[16]
for a pregnant woman with CHD are gestation between 28 and 32 weeks, during labor, and up to two weeks
after delivery.

PRE-PREGNANCY RISK ASSESSMENT AND COUNSELING IN MOTHERS WITH
CONGENITAL HEART DISEASE
It is recommended that all women with CHD should undergo careful pre-pregnancy assessment and
detailed counseling before conceiving. The counseling should include maternal cardiac and obstetric risks as
well as the fetal risks. This requires a multidisciplinary team approach comprising of an obstetrician,
cardiologist, neonatologist, and other specialists in some cases.

Maternal risk
Maternal risk stratification of women with CHD is based on the type of underlying CHD, whether the CHD
has been repaired or not, the presence of residual lesions with the resulting hemodynamics, and assessment
of patient specific cardiac and obstetric risk factors [1,4,5] . The assessment includes patient’s history,
electrocardiogram, detailed echocardiography, oxygen saturation, and additional testing, such as exercise
testing, catheterization, and advanced imaging in some cases. Maternal functional status is an important
determinant of pregnancy outcome. Cardiopulmonary exercise testing performed before conception can
[26]
predict maternal and neonatal outcomes in pregnant women with CHD . Lui et al. found that the peak
[27]
heart rate, percentage of maximum age predicted heart rate, and chronotropic index were associated with
the risk of maternal cardiac and neonatal adverse events. B-type natriuretic peptide or N-terminal pro B-
type natriuretic peptide may also be helpful .
[28]

The aim of risk stratification is not only to stratify but also identify modifiable risk factors and decide
whether a pre-pregnancy intervention may reduce the risk. Pre-pregnancy assessment should also include
careful review of medication for teratogenic potential. Commonly used cardiac medications such as
spironolactone, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, endothelin
receptor antagonists, and amiodarone are contraindicated during pregnancy. Oral anticoagulant use during
pregnancy is associated with increased risk of bleeding and thrombotic events as well as fetal loss and
teratogenicity (warfarin). These medications may have to be stopped before conception, if considered safe
[1,4]
for the mother .