Abnormal pregnancy

Introduction to Hypertension in Pregnancy

  • Hypertension can either arise in women who are normotensive before pregnancy or in those with existing hypertension.

  • Gestational Hypertension: A condition similar to gestational diabetes, where a previously normotensive woman develops hypertension during pregnancy.

Classifications of Hypertension in Pregnancy

  1. Gestational Hypertension

    • Develops during pregnancy in women who were previously normotensive.

  2. Preeclampsia

    • A multisystem disorder of unknown etiology characterized by high blood pressure and the presence of protein in urine (proteinuria).

  3. Eclampsia

    • Clinically defined as preeclampsia with the occurrence of generalized tonic-clonic seizures or coma.

  4. Chronic Hypertension

    • Existing hypertension prior to pregnancy.

  5. Preeclampsia or Eclampsia Superimposed on Chronic Hypertension

    • Preeclampsia or eclampsia occurs in a woman who already has chronic hypertension.

Prevalence and Progression

  • Primary Preeclampsia (70%):
    This refers to pregnancy-induced hypertension leading to preeclampsia or eclampsia.

  • Secondary Preeclampsia (30%):

    • Superimposed Preeclampsia and Eclampsia on Chronic Hypertension: 25% of cases.

    • Preeclampsia and Eclampsia Superimposed on Chronic Renal Disease: 5% of cases.

Classification by Severity

  1. Mild Preeclampsia:

    • Systolic BP: 140 - 160 mmHg

    • Diastolic BP: 90 - 100 mmHg

    • Proteinuria: Up to 2+

  2. Moderate Preeclampsia:

    • (not distinctly defined in the transcript)

  3. Severe Preeclampsia:

    • Systolic BP greater than 160 mmHg

    • Diastolic BP greater than 110 mmHg

    • Proteinuria: 3+ or more.

    • Possible symptoms: epigastric pain, severe headaches, visual changes.

Risk Factors for Preeclampsia

  • Primigravida:
    Young or elderly first-time mothers.

  • Family History of Hypertension and Preeclampsia

  • Placental Abnormalities:

    • Conditions like hyperplasia, molar pregnancy, twins, and placental ischemia.

  • Genetic Disorders and Thrombophilias

  • Preexisting Vascular Diseases

  • Immunological Phenomena

Etiology of Preeclampsia

  1. Abnormal Placentation:

    • Abnormal trophoblastic invasion of the uterine blood vessels.

  2. Immunological Maladaptation:

    • Incompatibility issues between maternal, paternal, and fetal tissues.

  3. Maternal Cardiovascular and Inflammatory Changes:

    • Maladaptive responses may affect normal physiological adaptations in pregnancy.

  4. Genetic Factors:

    • Influence the susceptibility to preeclampsia.

Pathogenesis of Preeclampsia

  • Poor placentation leads to inadequate invasion of uterine spiral arteries by cytotrophoblasts, resulting in:

    1. Incomplete Pseudovascularization:

    • Leads to decreased placental perfusion and vascular constriction.

    1. Altered Uterine Spiral Arteries:

    • The tunica media is not replaced by trophoblastic cells, perpetuating decreased perfusion and elevated maternal blood pressure.

  • Resulting endothelial dysfunction can lead to proteinuria due to compromised glomerular filtration capacity.

Clinical Features of Preeclampsia

  • Signs:

    • Increased weight gain (over 5 pounds a month or more).

    • Generalized edema and possibly pulmonary edema.

  • Alarming Symptoms:

    • Headaches (occipital or frontal), sleep disturbances, reduced urinary output.

    • Eye symptoms including blurred vision or visual disturbances.

Investigations

  • Assess for proteinuria.

  • Eye examinations for retinal issues.

  • Blood tests: Blood urea nitrogen (BUN), serum creatinine, liver function tests, complete blood count for thrombocytopenia.

  • Fetal monitoring using ultrasound for activity and umbilical artery flow velocity.

Maternal Complications

  1. Eclampsia (2% risk)

  2. Accidental hemorrhage

  3. Oliguria and anuria (absence of urine)

  4. Dimness of vision and potential for complete blindness.

  5. Preterm labor and HELLP syndrome (characterized by hemolysis, elevated liver enzymes, low platelet count).

Fetal Complications

  • Intrauterine fetal demise, growth restriction, asphyxia, and preterm birth.

Preventive Measures for Preeclampsia

  1. Regular antenatal checkups.

  2. Use of antithrombotic agents (e.g., low-dose aspirin).

  3. Calcium supplementation (2 grams/day).

  4. Nutritional supplements including antioxidants (Vitamins E and C), magnesium, and zinc.

  5. Diet with increased protein and low salt.

Management Objectives of Preeclampsia

  1. Stabilize hypertension and prevent progression.

  2. Avoid complications and eclampsia.

  3. Optimize timing for delivery and restore maternal health postpartum.

Treatment Modalities

  1. Rest:

    • Left lateral position to reduce vena cava compression.

  2. Diet:

    • Adequate protein intake and liberal fluid intake.

  3. Sedatives:

    • May help in reducing stress-related factors.

  4. Diuretics:

    • Used cautiously to avoid adverse effects.

  5. Antihypertensive Medication:

    • As prescribed by a physician. Common includes Methyldopa (250-500 mg TID).

Progress Chart Requirements

  • Blood pressure monitoring every 15-30 minutes.

  • Consistent state of edema and daily weight recordings.

  • 24-hour urine tests for protein.

  • Weekly blood tests for hematocrit, platelet counts, and liver function.

Indication for Labor Induction

  • Induce labor if preeclampsia does not improve with treatment; risks outweigh potential complications,

    cervical conditions unfavorable for vaginal delivery, or if the gestation has reached 37 weeks or beyond.

Management During Labor

  • Extended monitoring, liberal use of sedatives and antihypertensive treatments.

  • Careful tracking of fetal well-being.

  • Caution against the use of IV ergometrine due to potential risks.

  • Postnatal monitoring for 48 hours mandated.

Eclampsia

  • Defined as preeclampsia with seizures or coma.

  • Clinical progression includes:

    1. Premonitory Stage: Unconsciousness, facial and limb twitching.

    2. Tonic Stage: Body spasms, fixed eyeballs, cessation of breathing.

    3. Clonic Stage: Alternating contraction/relaxation, potential tongue biting.

    4. Coma Stage: Duration varies, patient may regain awareness post-episode.

Management of Eclampsia

  1. Seizure Management: Control convulsions and maintain airway during seizures.

  2. Oxygen Administration: 8-10 L/min for respiratory support.

  3. Termination of Pregnancy: Evaluated on a case-by-case basis.

  4. Postnatal Care: Continued monitoring and management to reduce maternal morbidity and address complications.

Conclusion

  • To effectively manage hypertensive disorders in pregnancy, healthcare professionals must ensure a rigorous monitoring plan and be adaptable with treatment based on the evolving condition of the mother and fetus. Maintaining a high degree of vigilance, especially in women with symptoms of worsening preeclampsia and eclampsia, is paramount for maternal and fetal outcomes.