Medical disorders in pregnancyFree in the app
Heart disease — mWHO risk classes
How risky pregnancy is for each heart condition.
Source: ESC 2018 · ESC 2025 (mWHO 2.0)Maternal cardiac event risk
| mWHO I (2.5–5%) | Mild pulmonary stenosis, PDA or MVP; repaired simple lesions (ASD, VSD, PDA); isolated ectopics. |
|---|---|
| mWHO II (6–11%) | Unoperated ASD or VSD; repaired tetralogy of Fallot; most arrhythmias. |
| mWHO II–III (10–19%) | Mild LV impairment (EF above 45%); HCM; mild mitral stenosis; moderate aortic stenosis; repaired coarctation. |
| mWHO III (19–27%) | EF 30–45%; previous PPCM with recovery; mechanical valve; Fontan; moderate mitral stenosis; severe asymptomatic aortic stenosis. |
| mWHO IV (40–100%) | Pulmonary hypertension; EF below 30% or NYHA III–IV; severe mitral stenosis; severe symptomatic aortic stenosis; Marfan aorta above 45 mm. Pregnancy not advised — discuss termination. |
Key points (ESC 2025)
- Pregnancy heart team for class II–III and above.
- Stop ACE inhibitors, ARBs, ARNI and SGLT2 inhibitors. DOACs not recommended.
- Vaginal birth preferred; CS for obstetric reasons or severe heart failure, outflow obstruction, uncontrolled arrhythmia, or warfarin at labour.
- Cardiac arrest: perimortem CS if no return of circulation by 4 minutes.
- Endocarditis prophylaxis not routine for vaginal or caesarean birth.
A summary for trained clinicians. Always check the full guideline, the patient in front of you and your hospital's protocol. Spotted an error? Tell us.