Congenital heart disease and safe pregnancy: the importance of being followed from before conception

By Cristiano Antonino On Nov 22, 2022

Congenital heart disease affects around 1% of babies born, and is the most frequent category of congenital malformations

Congenital heart disease requires specialist care and multidisciplinary diagnosis and treatment at all stages of life

Today, thanks to improved diagnostic techniques and therapies, more and more women with congenital heart disease are reaching adulthood and among them many wish to become mothers.

Pregnancy, however, can alter the cardiovascular balance and lead to complications, sometimes serious, for both mother and child.

This is why it is essential that all women with congenital heart disease who wish to become pregnant are followed from before conception so that they can be safely accompanied to the birth of their child.

Often, however, the desire for motherhood combined with ‘feeling good’ drives mothers-to-be to start a pregnancy without pausing to think about possible consequences for her and her little one.

What is congenital heart disease?

Congenital heart diseases are anatomical and functional cardiac changes caused by abnormalities in the development of the heart during the foetal period.

For example, a heart valve may be too small and thus prevent the proper passage of blood from one portion of the heart to another.

Or, there may be communication between the right and left halves of the heart where there should not be; or an entire portion of the heart, such as a ventricle, may be missing.

There are also cases where the great arteries that originate from the heart originate in the opposite way to how they normally do in a healthy heart.

These abnormalities may be evident as early as the foetus, or they may not manifest until after birth, sometimes even in adolescence or adulthood.

For some, a genetic basis is known, but for most, the cause is unknown.

Then there are acquired heart diseases, which represent alterations that occur for various reasons on a heart that was formed normally and born healthy.

How are congenital heart diseases diagnosed?

In the past, the discovery of a congenital heart disease took place only after birth, but today, with modern instrumentation, it is possible to suspect the presence of a structural heart disease as early as at obstetric screening in the first trimester and then confirm it at subsequent checks from 16 weeks onwards.

When this is not the case, since it is sometimes not possible to diagnose heart disease before birth, the suspicion of cardiac abnormality is placed by the neonatologists and paediatricians who receive the unborn child, and on the basis of symptoms and clinical signs they refer the child for a paediatric cardiological examination.

Is it therefore possible to become a mother in the case of congenital heart disease?

Thanks to the enormous progress in medicine, today it is possible to make increasingly early diagnoses and increasingly complex reconstructive surgeries, and thus become adults with a normal social and working life even with a severely malformed heart.

In women with congenital heart disease, becoming a mother is generally possible, but it is essential to be followed from the pre-conception period by professionals (both cardiologists and obstetricians) specialised in these pathologies for an appropriate course of treatment.

Specifically, it will be possible to assess the type of heart disease, whether to advise against pregnancy, whether to change treatment to avoid possible damage to the foetus, and whether to improve the heart condition before embarking on a pregnancy.

In addition, the examination informs the woman of possible risks of: transmission of congenital heart disease to the unborn child, premature birth, reduced foetal growth and worsening (not always completely reversible) of her heart condition.

Why should a woman with congenital heart disease be followed by cardiologists and obstetricians who are experts in this pregnancy condition?

During the nine months important cardiovascular changes occur that can alter the woman’s clinical balance.

The increase in circulating blood volume, up to three times the baseline value, the increase in heart rate, the reduction in blood pressure (except in women predisposed to hypertension), are all conditions that occur in any pregnancy, but in women with previous heart disease may not be well tolerated with sometimes serious consequences.

In general, arrhythmias and heart failure are the most frequent non-obstetric cause of complications during pregnancy, especially in the second and third trimester.

And labour is also a very demanding time from a cardiovascular point of view. The return to normal after childbirth in women with congenital heart disease may take up to 6 months or not at all.

Tools for assessing the likelihood of adverse events in pregnancy related to congenital heart disease

The most accurate and comprehensive tool for establishing maternal risk in women with congenital heart disease is the World Health Organisation (WHO) classification, which defines 4 risk classes:

Class 1. Includes heart diseases in which the risk of adverse events is superimposable to those of the general population

Class 2. Includes even quite complex heart diseases such as tetralogy of Fallot operated with a good functional result and without distant complications and some minor valvular pathologies.