Pregnancy & Heart Disease: How To Prevent

There is a misconception prevalent that women with heart disease should never get pregnant. But with a little planning & right information they can have a safe & healthy pregnancy. With the right planning, followups with Doctor and adherence to prescribed precautions pregnancy can be uneventful.

Let’s Understand How Pregnancy Effect You Heart.

Your heart has to pump 40% more blood to all body organs during pregnancy which means heart really has to work very hard. Blood vessels of pregnant female dilate to accumulate the increased blood flow, lowering blood pressure & blood become thicker, more likely to clot, which is actually nature’s way of protecting pregnant female from excessive bleeding during child birth.

A normal heart can handle all these physiological changes completely but for patients with heart disease, it is kind of extra load of work on ailing heart condition that require careful observation before conception.

What Should Be Done If Heart Patient Becomes Pregnant?

There are certain heart conditions which are congenital in nature & affect women of child bearing age. They are:

• Shunt lesions

Shunts are abnormal blood flow from holes between heart chambers and they include: Atrial septal defect (ASD) –hole between the upper chambers of the heart. Ventricular septal defect (VSD) – hole between the lower chambers of the heart. Patent ductus arteriosus (PDA) which means abnormal blood flow between the aorta and pulmonary artery.

If the hole is large, a fair amount of blood from the left side of the heart will flow back into the right side of the heart & then to lungs again causing strain on heart. This leads to enlarged heart, abnormal heart rhythms and increased pressure in lungs (pulmonary hypertension). Pulmonary hypertension, when severe, can cause blood flow across the shunt to move in reverse – condition known as Eisenmenger syndrome, this cause low level of oxygen in blood (cyanosis). Pregnancy is not recommended due to the high risk of the maternal death in such cases.

• Obstructive Lesions

This lesion reduces the blood flow to heart major blood vessels of the body. One such condition is coarctation of aortic (largest artery in the body) in which condition there is narrowing in the descending aorta. This condition can cause high blood pressure in pregnant women and reduced blood flow to placenta comprising fetus. Depending upon the severity you may need a procedure before or during pregnancy (2nd trimester).

• Complex lesions

Complex lesions like transposition of the great vessels if not corrected can lead to heart failure & leaky valves & worsening of condition during pregnancy. Similarly tetralogy of Fallot which includes a VSD, narrowing of the pulmonary valve and abnormal configuration of the aorta & cyanosis, if left untreated can lead to heart failure & arrhythmias. This condition needs correction before you pan pregnancy.

So in general, most women with congenital heart defects especially where corrective surgeries has already been done can safely become pregnant. However the outcome of pregnancy and risk of complication depend on the type of defect. How severe your symptoms are and whether you have heart muscle dysfunction, rhythm disorder, pulmonary hypertension with related lung disease.

• Valve disease & pregnancy

Rheumatic heart disease like aortic stenosis ( narrowing of aortic valve) & mitral valve (narrowing of mitral valve) make heart to work harder to pump increased blood volume out of narrowed valves. This in turn cause left ventricle of heart & enlarge called hypertrophy.

Bicuspid aortic valve is a congenital condition with 2 leaflets/cusps instead of three and this condition leads aortic valve stenosis in some cases.

During pregnancy as blood volume & heart rate both increases, this makes symptoms of mitral stenosis get worse. Left atrium (upper chamber of heart) become bigger and causes rapid irregular heart rhythm called atrial fibrillation, this is associated with increased risk of stroke. Also, mitral stenosis can lead to heart failure, breathlessness, fatigue & swelling. So during pregnancy with mitral stenosis, if symptoms are bothersome & cannot be controlled with medicine ballon valvuloplasty (PTMC) is done in 2nd trimester which is the safest time to undertake procedure.

• Pregnancy in women with prosthetic valve

Women with prosthetic valve can have complications during pregnancy because these females are on blood thinners for lifelong & certain other anticoagulant drugs which can be harmful to baby. In these patients heparin/ low molecular heparin should be used in 1st trimester (Initial 3months) followed by warfarin upto 36th weeks of pregnancy & then heparin/LMWH again till the time of delivery.

It is always better to consult your cardiologist before planning for pregnancy who can explain you potential risks & determine the best anticoagulant therapy routine for you with prosthetic valve.

• Arrhythmias and pregnancy

Abnormal heartbeats (arrhythmias) during pregnancy are common. Most of the time such arrhythmias are benign & do not cause much problem but sometime they indicate some serious heart condition detected only during pregnancy. But in all cases, pregnant lady should consult a cardiologist & must undergo desired tasks.

Heart Conditions Where Pregnancy Should Be Avoided:

• History Of Peripartum Cardiomyopathy In Previous Pregnancies.
• Eisenmenger Syndrome (High Pulmonary Artery Pressure Birth Reversal Of Blood Flow From Right Heart To Left Heart Instead Of Normal Left To Right Across Heart Holes
• Severe Left Ventricular Dysfunction (Weak Heart Muscle)
• Severe Mitral Stenosis – Severe Pulmonary Hypertension (Pph),
• Uncontrolled Blood Pressure, Diabetes.

What Precautions Should Be Taken By Heart Patients During Pregnancy?

• Restrict Salt Intake And Excessive Water Intake
• Avoid Certain Drugs Like Pain Killers, Blood Pressure Medicines Like ACE Inhibitors, ARBs Arni Etc.
• Proper Heart Medicines To Be Taken As Prescribed By Doctor
• Regular Follow Ups And Investigations