Classical triad and blood pressure assessment
The diagnosis is established in the presence of three key signs: elevated blood pressure, protein in the urine, and edema syndrome.
For an accurate assessment of the degree of hypertension, the mean arterial pressure (MAP) is calculated using the formula: diastolic pressure plus 1/3 of the difference between systolic and diastolic. Normally, this indicator is 90–100 mm Hg. The gold standard for diagnosis is ambulatory blood pressure monitoring (ABPM). Based on the proportion of time the blood pressure is elevated, the following are distinguished:
- Labile hypertension (elevation less than 25% of the time).
- Stable (25–50% of the time).
- Severe (more than 50% of the time).
Laboratory and instrumental monitoring
Assessment of the pregnant woman's condition requires an integrated approach. Urinary protein is initially detected using dipsticks, but a quantitative analysis of a 24-hour urine collection is necessary for an accurate diagnosis.
The mandatory minimum of examinations includes:
- Complete blood count and blood chemistry, peripheral blood smears, coagulogram.
- Assessment of diuresis and renal concentrating function.
- Monitoring of saturation, pulse, and respiration.
- Fundus examination.
- Ultrasound with Doppler flowmetry in the mother-placenta-fetus system.
In early-onset disease (before 20 weeks) or a burdened obstetric history, blood tests for congenital hemostatic defects are additionally performed.
HELLP syndrome: cardinal signs
This is a rapid-onset complication associated with high maternal and perinatal mortality. In the early stages, it masquerades as nausea and vague abdominal pain. The diagnosis is confirmed in the presence of the triad:
- Hemolysis: intravascular red blood cell destruction, appearance of schizocytes (> 0.27%), increase in indirect bilirubin (> 12 µmol/L) and lactate dehydrogenase (> 600 IU/L). The release of phospholipids triggers acute disseminated intravascular coagulation (DIC).
- Liver involvement: elevated ALT and AST (> 70 IU/L). Due to fibrin deposition and hepatocyte dystrophy, Glisson's capsule is stretched, causing characteristic pain in the right upper quadrant and epigastrium.
- Thrombocytopenia: depletion of the platelet pool (decrease < 100×10⁹/L) due to microthrombus formation.
Differential diagnosis
The symptoms of preeclampsia and its complications are often disguised as other pathologies. Preeclampsia itself must be differentiated from hypertension syndrome and primary kidney, liver, or CNS diseases.
Eclampsia (the convulsive form) is differentiated from epilepsy, infections (meningitis, encephalitis), vascular catastrophes (strokes, cerebral venous thrombosis, aneurysms), and metabolic disorders.
Diagnosis of HELLP syndrome is particularly challenging. Due to abdominal pain and vomiting, it can be mistaken for acute appendicitis, cholecystitis, pancreatitis, gastroenteritis, viral hepatitis, or acute fatty liver of pregnancy.
Management principles and hospitalization
It is impossible to completely cure severe preeclampsia prior to delivery. The main goal is to prevent eclampsia and, in early onset, prolong the pregnancy to 32–34 weeks.
All female patients are prescribed magnesium sulfate (from 12 to 25 g/day depending on severity), antihypertensive drugs, infusion therapy, and anticoagulants. Glucocorticoids are used for the prevention of fetal respiratory distress syndrome. Non-pharmacological management includes a high-protein diet, salt restriction (≤4 g/day), and bed rest (daytime bed rest up to 2–3 hours).
Patients with preeclampsia are hospitalized in a maternity hospital. For severe forms, transfer to a Level III ICU is indicated. Transportation is strictly contraindicated if bleeding develops.
Briefly: answers to topical questions
Which specific drugs are used for antihypertensive therapy in preeclampsia?
Several pharmacological groups of drugs are used for antihypertensive therapy in preeclampsia.
- Nifedipine is the drug of choice with sustained (extended) release.
- Methyldopa is used orally, but has limitations in the postpartum period due to the risk of depression.
- Amlodipine can be added to the therapy if necessary.
Monotherapy is possible in moderate preeclampsia, whereas severe forms require combination therapy with 2–3 drugs, strictly considering their safety for the fetus.
What are the absolute indications for emergency delivery in severe preeclampsia?
Indications for emergency delivery include eclampsia and its complications (cerebral hemorrhage or edema, pulmonary edema, acute renal failure, DIC syndrome, placental abruption), failure of treatment for severe or critical preeclampsia, oliguria (less than 30 ml over 2 hours), acute fetal hypoxia, stage III fetal growth restriction combined with oligohydramnios, and premature rupture of membranes. If therapy is ineffective or complications are present, emergency delivery is indicated; onset of labor is an indication when therapy is ineffective and/or complications develop.
What pathological changes in the fundus are detected in preeclampsia?
Hypertensive disorders reveal signs of hypertensive retinopathy of varying severity in the fundus.
- Retinal hemorrhages and microaneurysms.
- Hard exudates and cotton-wool spots.
- Papilledema (optic disc edema) and/or macular edema.
These pathological changes correlate with a poor prognosis and have high prognostic significance for assessing the severity of the patient's condition.
What clinical and laboratory criteria indicate severe preeclampsia?
Severe preeclampsia is diagnosed based on a number of specific clinical and laboratory criteria.
| Criterion | Value in severe preeclampsia |
|---|---|
| Blood pressure | Systolic ≥160 mm Hg or diastolic ≥110 mm Hg |
| Oliguria | <500 ml/day (<30 ml/h) |
| Thrombocytopenia | <100×10⁹/L |
| Liver function | Elevated ALT and AST |
| Clinical symptoms | Epigastric or right upper quadrant pain, headache, visual disturbances |
Severe preeclampsia is also indicated by the presence of hemolysis, elevated creatinine levels, development of HELLP syndrome, pulmonary edema, cyanosis, and antenatal fetal death.
What is the administration regimen (loading and maintenance doses) of magnesium sulfate in preeclampsia?
The magnesium therapy regimen includes intravenous administration of a loading dose and a maintenance dose of magnesium sulfate.
- Loading dose: 4–6 g IV over 15–20 minutes. If ineffective, an additional 2 g may be administered over 3–5 minutes.
- Maintenance infusion: 1–2 g/h IV via a syringe pump.
- Duration: administration is continued for at least 24–48 hours after delivery or the last eclamptic seizure.
To remember the classical triad of preeclampsia, use the abbreviation OPA: Oedema, Proteinuria, Arterial hypertension.
Class and exam questions
How to detect hidden edema in a pregnant woman?
Hidden edema is diagnosed by pathological weight gain exceeding 300 grams in one week.
What is the danger of subcapsular liver hematoma in HELLP syndrome?
The hematoma can rupture upon the slightest mechanical impact (e.g., increased intra-abdominal pressure during labor or the use of the Kristeller maneuver), leading to massive intra-abdominal hemorrhage.
How is non-convulsive eclampsia diagnosed?
This is a diagnostically challenging variant. It is diagnosed if a patient with symptoms of preeclampsia develops a comatose state without preceding specific seizures.
What are the main causes of maternal mortality in preeclampsia?
Fatal outcomes are most commonly caused by severe brain damage (edema, hemorrhage, ischemia), acute hepato-renal failure, sepsis, and massive coagulopathic postpartum hemorrhage.
What else to study on this topic
- Pathogenesis of DIC syndrome in the setting of intravascular hemolysis
- Differential diagnosis of eclampsia and cerebrovascular events
- Clinical pharmacology of magnesium sulfate in obstetric practice
- Severe neurological manifestations and indications for brain CT/MRI
- Management of fasting/reduction days for pathological weight gain
Master the entire topic in the "Obstetrics and Gynecology" course
This is a summary. The course covers everything tested in classes and exams.
- Complete guide on "Diagnosis and Monitoring of Preeclampsia" and 973 other pages of the subject
- Assignments and quizzes after every topic — just like in a colloquium
- AI tutor answers questions on the topic anytime
- 21 video lessons on the subject
Other topics in the "Obstetrics" section
Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.