Antenatal Care: Hypertensive Disorders in Pregnancy
Managing the Risks of High Maternal Blood Pressure
Hypertensive disorders in pregnancy are among the leading causes of preventable maternal mortality. These conditions can lead to serious complications for both the mother and fetus, including preterm birth, placental abruption, intrauterine growth restriction, and stillbirth. The risk is particularly elevated in low- and middle-income countries where access to timely and adequate care is limited.
Hypertensive disorders in pregnancy are classified into:
- Chronic Hypertension: Hypertension diagnosed before pregnancy or before 20 weeks of gestation.
- Gestational Hypertension: New-onset hypertension (≥140/90 mmHg) without proteinuria after 20 weeks of gestation.
- Pre-eclampsia: New-onset hypertension after 20 weeks of gestation accompanied by proteinuria and/or signs of systemic involvement (e.g., liver dysfunction, thrombocytopenia, renal insufficiency, or neurological symptoms).
- Eclampsia: A life-threatening condition characterized by the occurrence of generalized tonic-clonic seizures in a woman with pre-eclampsia that cannot be attributed to other causes.
Pre-eclampsia and eclampsia are among the leading direct causes of maternal and perinatal morbidity and mortality and require urgent intervention to prevent severe complications such as stroke, pulmonary edema, kidney failure, preterm birth, intrauterine growth retardation and death. The pathophysiology of pre-eclampsia is complex and not entirely understood, but it is believed to involve abnormal placentation leading to systemic endothelial dysfunction and inflammation. Early detection, effective management, and timely referral of women with hypertensive disorders during pregnancy are crucial.
What Are the Benefits of Managing Hypertensive Disorders in Pregnancy?
- Significantly reduces the risk of maternal and fetal death.
- Prevents progression from mild hypertension to severe pre-eclampsia and eclampsia.
- Improves birth outcomes through timely intervention.
- Enhances the quality of antenatal care, childbirth, and postnatal care.
- Reduces long-term health complications for mothers, such as kidney and cardiovascular diseases.
Signs & Symptoms
Among the hypertensive disorders during pregnancy are:
- Pre-eclampsia without severe features
- Pre-eclampsia with severe features
- Eclampsia
Pre-eclampsia without severe features is characterized by elevated blood pressure, with a systolic reading of 140 mmHg or higher (but less than 160 mmHg) and a diastolic reading of 90 mmHg or higher (but less than 110 mmHg). Protein is present in the urine, typically measured as 300 mg or more in a 24-hour collection, a protein-to-creatinine ratio of 0.3 or higher, or a urine dipstick reading of 2+. Affected individuals may experience mild or intermittent headaches, swelling in the hands or feet, sudden weight gain due to fluid retention, and general fatigue or discomfort. While symptoms are less severe, close monitoring is essential to prevent progression.
When pre-eclampsia progresses to include severe features, it indicates a more critical stage of the condition requiring urgent management. Blood pressure rises significantly, with systolic readings of 160 mmHg or higher and diastolic readings of 110 mmHg or higher. Women may experience persistent headaches, visual disturbances such as blurring or scotomas, and pain in the right upper quadrant or epigastric region. Additional signs include reduced fetal growth (intrauterine growth restriction), low amniotic fluid levels (oligohydramnios), and decreased urine output (oliguria of less than 500 ml in 24 hours). In some cases, pulmonary edema may also occur. These symptoms indicate increased risk for both maternal and fetal complications and require immediate evaluation and intervention.
The following laboratory findings support the diagnosis of pre-eclampsia with severe features and help assess the extent of organ involvement:
- Proteinuria equal to or greater than 3 grams per 24-hour urine collection or the equivalent on a urine dipstick
- Compromised kidney function, indicated by a serum creatinine level greater than 1.2 mg/dL
- Low platelet count (thrombocytopenia) with levels below 150,000/mm³
- Elevated Lactate Dehydrogenase (LDH) levels at or above 600 IU
- Increased liver enzymes, specifically elevated serum transaminase levels (ALT, AST)
Complications from pre-eclampsia with severe features can be life-threatening for both the mother and fetus. These complications often result from multi-organ involvement and require urgent medical attention.
- Eclampsia: The onset of seizures in a woman with pre-eclampsia.
- HELLP Syndrome: HELLP is associated with high maternal mortality and morbidity, including risks such as disseminated intravascular coagulation (DIC), liver hematoma or rupture, liver failure, and renal failure. This serious condition includes:
- Hemolysis: Evidence of anemia with fragmented red blood cells on a blood film.
- >Elevated liver enzymes: Indicating liver dysfunction (transaminases more than twice the normal range).
- Low platelets: A platelet count of less than 150,000/mm³.
- Cerebral hemorrhage: Bleeding in the brain due to severely elevated blood pressure.
- Posterior reversible encephalopathy syndrome (PRES): A neurological disorder causing headaches, confusion, seizures, and vision changes.
- Reversible cerebral vasoconstriction syndrome: A rare cause of severe headaches due to narrowing of brain blood vessels.
- Intrauterine growth restriction (IUGR) and fetal compromise: Reduced blood flow to the fetus can impair growth and well-being.
- Renal failure: Impaired kidney function requiring supportive care.
- Placental abruption: Premature separation of the placenta from the uterine wall, posing serious risk to mother and baby.
How to Implement
1. Ensure Routine Quality Antenatal Care
Ensure there is blood pressure monitoring and urine protein testing at every antenatal visit. Educate the mother on danger signs and be vigilant for any signs or symptoms suggestive of pre-eclampsia.
2. Identify and Monitor High-Risk Individuals
Identify individuals at higher risk of developing pre-eclampsia early in pregnancy (e.g., those with a history of pre-eclampsia, multiple pregnancies, pre-existing hypertension, diabetes). Follow up and closely monitor these individuals.
3. Diagnose Pre-Eclampsia
Follow clear diagnostic criteria for pre-eclampsia, including accurate blood pressure measurement technique and appropriate assessment for proteinuria and other organ involvement.
4. Monitor and Evaluate G-ANC Implementation
Determine the severity of pre-eclampsia (mild, severe) based on blood pressure readings and the presence of signs and symptoms of organ dysfunction. This guides the management plan.
5. Initiate Appropriate and Timely Treatment Based on Severity
- Administer antihypertensive medications to control high blood pressure and prevent complications like stroke.
- Use Magnesium Sulfate for the prevention and treatment of eclamptic seizures. Ensure strict adherence to protocols for proper loading and maintenance of doses and monitor for magnesium toxicity (e.g., loss of reflexes, respiratory depression). Calcium Gluconate should be readily available as an antidote.
- Monitor fluid intake and output carefully to avoid fluid overload, especially in severe pre-eclampsia.
- Regularly assess fetal well-being through methods like non-stress tests (NSTs) or biophysical profiles (BPPs).
- Plan to deliver the baby/placenta: The decision on when and how to deliver depends on the severity of the pre-eclampsia, gestational age, and fetal well-being. In severe cases, delivery may be necessary even if preterm.
6. Monitor During Postpartum Period
Continue to monitor blood pressure and other symptoms in the postpartum period, as pre-eclampsia can sometimes worsen or even develop after delivery. Educate the woman about potential warning signs and when to seek medical attention
7. Refer as Needed
Establish clear pathways for referral to higher levels of care when needed, especially for severe pre-eclampsia or eclampsia. Ensure timely and safe transfers.
Management Plan
| Management Plan Interventions |
|---|
1. Stabilization
|
2. Seizure Control
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3. Blood Pressure Management
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4. Delivery
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5. Postpartum Care
|
Key Indicators
- Case fatality rate due to pre-eclampsia and eclampsia.
- Near-miss rate due to pre-eclampsia and eclampsia.
- Preterm birth rate in women with to pre-eclampsia and eclampsia.
- Incidence rate of eclampsia.
- Time from identification of severe pre-eclampsia to delivery.
- Healthcare worker knowledge and adherence to guidelines.
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Tips
- Capacity Building: Maintain consistent and quality training and capacity building of health care workers. Regularly run drills and simulations within the maternity/ labour ward to ensure health workers are up-to-date with the management of pre-eclampsia/eclampsia.
- Commodity Security: Ensure the emergency medicines are well-stocked and available during an emergency.
- Communication: Maintain clear and open communication with the pregnant person and their family, explaining the condition, management plan, and potential risks. Address their concerns and answer their questions.
- Documentation: Accurately document all assessments, interventions, and observations, including blood pressure readings, medications administered, and fetal monitoring results.
- Effective Collaboration: Work with other healthcare professionals, including midwives, nurses, obstetricians, and anesthetists, to provide comprehensive care.
Challenges
- Limited Resources: In some settings, access to essential medications (like magnesium sulfate), monitoring equipment, and trained personnel may be limited.
- Late Presentation: Some pregnant individuals may present late for antenatal care, making early detection challenging. Community outreach and education can help address this.
- Adherence to Guidelines: Ensuring consistent adherence to protocols across all healthcare workers can be difficult. Regular training, supervision, and audits can help.
- Referral Delays: Delays in transferring patients to higher levels of care can negatively impact outcomes. Streamlining referral processes is essential.
