Pregnancy outcomes in women with the highest cardiovascular risk (mWHO class IV): A single-centre study

The modified World Health Organization (mWHO) classification of maternal risk is used to estimate morbidity and mortality in pregnant women with cardiovascular disease. Despite guidelines advising against pregnancy in the highest risk category (mWHO Class IV), successful outcomes have been achieved in select managed cases with specialised multidisciplinary care. This single-centre study examines pregnancy outcomes in this high-risk group.

We conducted a retrospective cohort study of 32 pregnancies in 30 women classified as mWHO Class IV between 2008 and 2022. Maternal demographics, cardiac and obstetric complications, delivery details, neonatal outcomes, and long-term follow-up data were collected and analysed.

The mean maternal age at delivery was 29.6 ± 5.1 years. Pulmonary arterial hypertension (PAH) and systemic ventricular dysfunction were the most prevalent conditions. Cardiovascular events occurred in 65.6 % of pregnancies, with PAH accounting for the majority. All women delivered via Caesarean section, with 93.7 % under general anaesthesia. Preterm birth occurred in 75 % of cases, and 87 % of neonates required NICU admission. One maternal death occurred in the late postpartum period. At one year, the major adverse cardiovascular event (MACE) rate was 9.3 %. Long-term follow-up revealed three additional maternal deaths.

Although pregnancy in women with mWHO Class IV disease carries substantial risk, favourable outcomes are achievable in a tertiary centre with a specialised Pregnancy Heart Team. However, the burden of morbidity remains high, reinforcing the need for early counselling, close surveillance, and long-term follow-up in this vulnerable population.