Essential or secondary hypertension in pregnancy

Hypertension in pregnancy is a common and significant complication that can affect both maternal and foetal outcomes. It can be classified into two main types:

• Essential (primary) hypertension: Persistent high blood pressure (BP) ≥140/90 mmHg diagnosed before pregnancy or before 20 weeks gestation, not attributed to a specific cause.
• Secondary hypertension: High blood pressure resulting from identifiable causes such as kidney disease, endocrine disorders, or coarctation of the aorta.

• Essential hypertension constitutes the majority of hypertension cases in pregnancy.
• Secondary hypertension is less common than essential hypertension, but crucial to diagnose for targeted treatment.

• Elevated blood pressure.
• May be asymptomatic.
• Nonspecific symptoms such as headaches or changes in vision.
• Clinical features associated with underlying causes in secondary hypertension.

• Blood pressure ≥ 140/90 mmHg recorded persistently before pregnancy or before 20 weeks gestation.
• Detailed Medical History and Physical Examination: To identify signs suggestive of secondary causes.
• Laboratory Tests and Imaging: Kidney function tests, thyroid function tests, and doppler ultrasound of renal arteries, among others, to identify the underlying cause.
• Essential hypertension is a diagnosis of exclusion, made when underlying causes have been ruled out.

• Antihypertensive Therapy: The goal is to manage blood pressure effectively to reduce the risk of maternal and foetal complications while minimising medication side effects.
• Regular Prenatal Care: Essential for monitoring blood pressure, assessing foetal growth and well-being, and detecting any complications early.
• Delivery Planning: The timing and mode of delivery should be carefully planned based on the severity of hypertension, gestational age, and overall foetal and maternal health.

Essential Hypertension:

• Medication: Antihypertensive therapy may be adjusted, considering medications that are safe during pregnancy (e.g., labetalol, methyldopa, nifedipine).
• Lifestyle Modifications: Encourage dietary modifications, reduced sodium intake, and regular physical activity as appropriate.

Secondary Hypertension:

• Targeted Treatment: Management of the underlying cause in addition to controlling high blood pressure.
• Multidisciplinary Approach: Collaboration with specialists (e.g., nephrologists, endocrinologists) for comprehensive care.

Hypertension in pregnancy can lead to several complications, affecting both the mother and the foetus. These include, but are not limited to:

• For the Mother: Pre-eclampsia/eclampsia, HELLP syndrome (Haemolysis, Elevated Liver enzymes, Low Platelet count), placental abruption, and increased risk of cardiovascular disease.
• For the Foetus: Intrauterine growth restriction (IUGR), preterm birth, low birth weight, and in severe cases, stillbirth.

• Understanding the differences between essential and secondary hypertension in pregnancy is crucial for effective management and improving pregnancy outcomes.
• Interdisciplinary care, involving obstetricians, cardiologists, and other specialists as needed, is key to addressing the complex needs of pregnant women with hypertension.
• Medical students should appreciate the importance of early detection, careful monitoring, and individualised treatment plans in managing these patients.