Gestational hypertension

Definition:

Gestational Hypertension is defined as the development of new-onset hypertension (blood pressure ≥ 140/90 mmHg) after 20 weeks of pregnancy in a woman previously normotensive, without the presence of proteinuria or other features of pre-eclampsia.

Epidemiology:

Affects approximately 6-17% of pregnant women.
It is one of the most common medical complications of pregnancy.

Risk Factors:

First pregnancy (nulliparity)
Multiple gestation (e.g., twins or triplets)
Family history of hypertension or pre-eclampsia
Advanced maternal age (>35 years)
Pre-existing medical conditions such as diabetes or kidney disease
Obesity
History of gestational hypertension or pre-eclampsia in a previous pregnancy

Pathophysiology:

The exact mechanism is not fully understood, but it is thought to involve abnormal placental development and function leading to impaired placental blood flow and resulting in systemic vascular resistance and hypertension.

Clinical Features

Signs and Symptoms:

Elevated blood pressure detected during prenatal visits, without additional signs of pre-eclampsia such as proteinuria or severe features.
May be asymptomatic, with hypertension detected only through routine antenatal care.
In some cases, women may report nonspecific symptoms such as headaches or changes in vision.

Diagnosis:

Blood pressure ≥ 140/90 mmHg on two separate occasions at least 4 hours apart, after 20 weeks of gestation, in a previously normotensive woman.
Absence of proteinuria or other systemic findings suggestive of pre-eclampsia.

Management

Antenatal Care:

Close monitoring of blood pressure and fetal well-being.
Lifestyle modifications, including dietary salt reduction and increased physical activity, may be recommended.
Antihypertensive medication may be considered in cases of severe hypertension (BP ≥ 160/110 mmHg) to prevent maternal complications, though the choice of medication must consider fetal safety.

Delivery:

The timing of delivery in gestational hypertension depends on the gestational age, control of blood pressure, and fetal condition.
Delivery is typically recommended at 37 weeks of gestation if blood pressure is controlled and there are no signs of fetal distress or pre-eclampsia.
Earlier delivery may be considered in cases of uncontrolled hypertension or if pre-eclampsia develops.

Postpartum Care:

Blood pressure typically returns to normal by 12 weeks postpartum. However, women with gestational hypertension are at increased risk of developing chronic hypertension and cardiovascular disease later in life.
Postpartum follow-up is important to ensure resolution of hypertension and to provide counseling on long-term cardiovascular risk reduction.

Complications

Progression to pre-eclampsia: A significant proportion of women with gestational hypertension may develop pre-eclampsia.
Increased risk of placental abruption, preterm delivery, and low birth weight.
Long-term, women with a history of gestational hypertension have an increased risk of chronic hypertension, type 2 diabetes, and cardiovascular disease.

Summary

Gestational Hypertension is a condition characterized by new-onset hypertension after 20 weeks of gestation without proteinuria or other systemic features of pre-eclampsia. It requires careful monitoring and management to prevent complications for both the mother and the fetus. Understanding the risk factors, pathophysiology, clinical management, and implications of gestational hypertension is crucial for medical students and healthcare professionals involved in obstetric care.