By Dr Faith Njue, Cardiologist, Subiaco
Cardiovascular disease complicates 1-4% of pregnancies and accounts for up to 15% of maternal mortality. It is the leading cause of maternal mortality in Australia.
The risk during pregnancy depends on the specific cardiac condition and current clinical status of the woman. Risk stratification guides management in pregnancy.
There are several classifications or risk scores for assessing maternal cardiovascular risk in pregnancy, the most well-established risk assessment for acquired disease is CARPREG (Cardiac Disease in Pregnancy) and the modified WHO Classification. The ZAHARA risk score is well validated for congenital heart disease.
Some of the identified risk factors include advanced maternal age, obesity, hypertension, smoking and diabetes, which all have increasing prevalence in Australia’s pregnant population.
The associated morbidity and mortality is even higher with Aboriginal and Torres Strait Islander women – between 2012 and 2018 the maternal mortality ratio of these women was 20.2 per 100,000 women giving birth.
In the same period, the MMR for non-Indigenous women was 5.5 per 100,000 women giving birth. This is likely related to the higher prevalence of valvular heart disease due to rheumatic heart disease.
Current research
Research is also uncovering more evidence of long-term cardiovascular risk in women related to adverse pregnancy outcomes like pre-eclampsia and gestational hypertension, with some evidence of long-term risk to the child.
Emerging data shows that preterm birth – less than 37weeks – is also associated with short-to-longer-term cardiovascular disease risk in the mother and long-term cardiovascular disease risk in the child.
Although the exact pathophysiology is uncertain, APOs are likely caused by underlying metabolic or vascular abnormalities that originate with defective placentation.
Management
Management of adverse pregnancy outcomes or underlying risk factors is essential. Cardiovascular risk is increased almost 2-4-fold in women who have had an APO.
This has significant implications for individuals and wider society as this is risk identified in a relatively young population. North American data demonstrated that cardiovascular mortality rates among women aged 35 to 44 years of age have been increasing on average since 1997.
Women who have experienced adverse pregnancy outcomes are at high risk for several types of cardiovascular disease, including heart failure with preserved ejection fraction (HFpEF) later in life.
Key messages
- Cardiovascular disease is the leading cause of maternal mortality in Australia.
- Adverse pregnancy outcomes significantly increase the risk of subsequent cardiovascular issues.
- Cardio-obstetrics and multidisciplinary care of women with cardiac disease in pregnancy improves outcomes.
Improving outcomes
The development of cardio-obstetrics and multidisciplinary care of women with cardiac disease in pregnancy has been shown to improve outcomes. Cardio-obstetrics is an expanding subspecialty within cardiology that focuses on the prevention, early detection, and appropriate management of cardiovascular disease in pregnancy.
Patients with known cardiac conditions should be referred for pre-conception counselling. This is particularly important for women with high-risk conditions like cardiomyopathy, aortopathy or prosthetic valves. It should also ideally be offered for women with significant cardiovascular risk factors.
This also extends to patients being offered, or undergoing, assisted reproduction. Pre-conception counselling would also involve a review of cardiac medications to avoid those associated with teratogenicity.
Currently, cardio-obstetric services are offered at Fiona Stanley Hospital with multidisciplinary involvement of cardiology, obstetrics, maternal-foetal medicine specialists and anaesthetists. It is also available in the private sector.
Author competing interests- nil
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