Predicting the risk of primary maternal cardiac complications during pregnancy
Risk stratification for women with pre-existing congenital or acquired heart disease, or arrhythmias
Pre-pregnancy counseling to establish realistic expectations regarding maternal morbidity
When NOT to Use
The CARPREG II score is designed to predict MATERNAL cardiac outcomes, not fetal or neonatal outcomes. Furthermore, it does not factor in obstetric risk factors (e.g., maternal age, extreme obesity, or preeclampsia risk) which can independently exacerbate cardiac reserve.
Outperforms the original CARPREG and ZAHARA indices in modern validation cohorts
Integrates process-of-care variables (like >20 weeks at first assessment) reflecting the reality of delayed antenatal care
Evaluated on a massive, contemporary dataset of high-risk obstetric conditions
Known Limitations
Derived largely in high-income tertiary care centers with expert multidisciplinary teams; actual risks in lower-resource settings may be significantly higher than predicted
May overestimate risk in the lowest-scoring brackets and slightly underestimate risk in some mid-range cohorts (like certain valvular diseases)
Section 4
Next Steps
High Risk (Score ≥ 4)
01
Immediate referral to a specialized multidisciplinary Cardio-Obstetric team
02
Early formulation of a highly detailed labor and delivery plan (including fluid management and precise anesthesia targets)
03
Deliver strictly at a tertiary care center equipped with adult cardiovascular ICU and ECMO capability
04
Consider early delivery if maternal hemodynamics deteriorate heavily in the late third trimester
Complementary Guidelines
Current expert consensus recommends utilizing CARPREG II alongside the modified WHO (mWHO) classification. While mWHO excels at identifying absolute contraindications to pregnancy (Class IV), CARPREG II offers superior, individualized statistical prediction of specific event rates.
Section 5
Evidence Appraisal
Primary Derivation Reference
Pregnancy Outcomes in Women With Heart Disease: The CARPREG II Study.
Silversides CK et al. • J Am Coll Cardiol.. 2018;May 29;71(21):2419-2430. Derivation study comprising over 1,900 pregnancies across tertiary Canadian centers demonstrating superior C-statistics.
Section 6
Literature
The CARPREG Registry
The Cardiac Disease in Pregnancy (CARPREG) registry was established in Canada to track outcomes for pregnant women with structural, congenital, or arrhythmic heart disease. The CARPREG II update was necessary to adapt to modern medical advancements, incorporating deeper nuances like pulmonary hypertension and aortopathy that were missing from the pioneering original model.
