Caring for your baby starts before birth: preparing for pregnancy, attending check-ups and having the planned scans. This article looks at congenital heart defects, the factors associated with them, what can be done beforehand and how they are screened for.
Congenital heart defects: what are we talking about?
These are heart malformations present from birth, which form while the heart develops in the womb (NHS). They affect close to 1% of children at birth (HUG) and are the most common congenital anomalies (MSD Manual). Their severity varies a great deal: some need early treatment, others are minor, and small openings between the heart chambers may never cause a problem (NHS). In infants, the most common are ventricular and atrial septal defects (MSD Manual).
Which factors are associated?
In most cases, no specific cause is identified (HUG). Some situations are nevertheless associated with a higher risk:
- a genetic or chromosomal abnormality, for example Down syndrome (HUG);
- maternal diabetes, rubella during pregnancy or certain teratogenic medicines, such as lithium, isotretinoin or some anticonvulsants (MSD Manual);
- smoking, obesity and gestational diabetes (NHS);
- the use of toxic substances, in particular alcohol (HUG).
These associations do not mean that a cause is always found. Do not blame yourself: talk to your doctor or midwife.
Preparing for pregnancy: folic acid, vaccination, lifestyle
Folic acid. A supplement of 400 micrograms a day is recommended as soon as you start trying to conceive, ideally about 3 months beforehand, until the end of the 12th week of pregnancy. A higher dose (5 mg) is prescribed in some situations, such as diabetes or epilepsy (Public Health Agency). It is mainly aimed at preventing neural tube defects.
Rubella. If contracted during the first three months, it can cause miscarriage or congenital anomalies. The MMR vaccine is the only protection, but it cannot be given during pregnancy: check your vaccination status before conceiving (European vaccination information portal).
Lifestyle. The NHS advises getting help to stop smoking, avoiding alcohol, and seeing a doctor before pregnancy if you have diabetes or take regular medication, without ever stopping a prescribed medicine without advice (NHS).
Prenatal screening by ultrasound
Many heart defects are picked up during pregnancy ultrasound scans. In the United Kingdom, the heart is examined at the 20-week scan, which does not, however, detect every case: some heart defects are diagnosed later (NHS). If there is any doubt, a specialised fetal heart scan may be requested. Keeping to the prenatal follow-up schedule offered by your healthcare professional therefore remains important. If a heart defect is found before birth, the delivery can be planned with the paediatric cardiology team.
Warning signs in the newborn
Signs vary: difficulty feeding, slow weight gain, breathlessness or sweating during feeds, bluish or greyish skin or lips, an unusually floppy baby (NHS, MSD Manual). A heart murmur may also be heard with a stethoscope, which does not always mean there is a disease. In some maternity units, pulse oximetry screening is carried out before discharge (MSD Manual). Symptoms may not appear until later.
Paediatric cardiology and follow-up
When a heart defect is suspected or confirmed, the child is referred to a specialist paediatric cardiology team, which clarifies the diagnosis with appropriate tests. Depending on the defect, simple monitoring, medicines (for example diuretics or antiarrhythmics) or surgery, either minimally invasive or open-heart, may be offered, sometimes shortly after birth, sometimes later (NHS). Some abnormalities, such as a small hole between two chambers, can often be left untreated. Symptoms may appear at birth, during childhood, or only in adolescence or adulthood. Most affected adults have been followed in paediatric cardiology since childhood (HUG).
When to seek medical advice
See a doctor promptly if your infant feeds poorly, breathes fast or with effort, sweats a lot while feeding or has blue lips. If the lips or skin turn blue, or the baby collapses or stops responding, call the emergency services. Before a pregnancy, seek advice if you have diabetes, a chronic condition, regular medication, a family history of malformation or any doubt about your vaccination.
Further reading at La Rose Clinic
Frequently asked questions
How common are congenital heart defects?
They affect close to 1% of births and are the most common congenital anomalies.
What is folic acid for?
It is recommended before and in early pregnancy, at 400 micrograms a day, mainly to prevent neural tube defects. A higher dose may be prescribed in some cases.
Should I be vaccinated against rubella before pregnancy?
Yes, check your vaccination status before conceiving, because the MMR vaccine cannot be given during pregnancy.
Does an ultrasound detect every heart defect?
No. Ultrasound picks up many of them, but not all: some are diagnosed after birth.
References
- Congenital heart disease (NHS) (nhs.uk)
- Planning your pregnancy (NHS) (nhs.uk)
- Malformations congénitales du cœur (hug.ch)
- Revue générale des anomalies cardiovasculaires congénitales (msdmanuals.com)
- Folic acid (Public Health Agency) (publichealth.hscni.net)
- Rubéole : vaccination (vaccination-info.europa.eu)
This article is for information only. It does not replace a medical consultation: if in doubt, talk to your doctor.
