Cardiac Disease in Pregnancy

Normal Cardiovascular Adaptations vs. Pathological Strain

Pregnancy places immense demands on a woman's circulatory system. Normal physiological adaptations include a dramatic rise in blood volume—increasing by up to 40 to 50 percent—alongside a surge in cardiac output and a drop in systemic vascular resistance. While a healthy heart handles this easily, a diseased heart struggles. Midwives must distinguish normal gestational complaints from signs of cardiac decompensation.

• Normal Adaptation: Mild resting tachycardia, soft systolic murmurs due to increased flow, and dependent pitting edema late in pregnancy.
• Pathological Strain: Persistent rales in the lung bases, significant jugular venous distension, progressive cyanosis, and a loud, harsh systolic or any diastolic murmur.

Functional Classification of Cardiac Disease in Pregnancy

The New York Heart Association (NYHA) functional classification system helps midwives and doctors categorize how much a heart condition limits a pregnant woman's physical activity. This system guides both counseling and clinical monitoring throughout antenatal visits.

1. Class I: Uncompromised; ordinary physical activity causes no discomfort, fatigue, or palpitation.
2. Class II: Slightly compromised; ordinary physical activity causes slight fatigue or breathlessness, but the woman is comfortable at rest.
3. Class III: Markedly compromised; less-than-ordinary activity causes significant fatigue, dyspnea, or chest pain, though she remains comfortable at rest.
4. Class IV: Severely compromised; the woman experiences cardiac symptoms even while resting, making any physical activity unbearable.

Identifying High-Risk Signs and Symptoms in the Antenatal Period

Routine antenatal care for women with cardiac conditions requires a high index of suspicion. Midwives must actively screen for red-flag symptoms that suggest the cardiovascular system is failing under the extra load.

Common warning signs include progressive dyspnea that disrupts sleep, orthopnea requiring extra pillows, nocturnal cough, hemoptysis, syncope during or after exertion, and chest pain linked to myocardial ischemia. Any new-onset arrhythmia or rapid weight gain from fluid retention must be reported immediately to the obstetrician and cardiologist. Early recognition prevents sudden maternal collapse in resource-constrained settings.

Multidisciplinary Antenatal and Intrapartum Management

Managing cardiac disease during pregnancy and childbirth requires a synchronized team approach involving midwives, obstetricians, cardiologists, and anesthetists. Antenatal visits focus on serial growth scans, regular functional assessments, and avoiding teratogenic medications.

During labor, the primary goal is minimizing cardiac workload. Midwives should encourage left lateral positioning to prevent aortocaval compression, provide adequate pain relief to blunt the stress response, and carefully monitor fluid balance to avoid overloading the circulation. Epidural anesthesia is often favored to smooth out blood pressure fluctuations during contractions.

Midwifery Care During the Critical Postpartum Window

The immediate postpartum period is the most dangerous time for a woman with heart disease. Following placental delivery, the autotransfusion of blood from the uteroplacental unit back into the maternal circulation causes a sudden surge in preload. This abrupt shift can easily trigger acute pulmonary edema in vulnerable hearts.

Midwives must maintain rigorous monitoring of vital signs, fluid intake, and urine output for at least 24 to 72 hours after birth. Care must be taken during early ambulation, and postpartum hemorrhage must be managed carefully since blood loss is poorly tolerated by failing hearts, yet aggressive fluid resuscitation can also cause overload.