Preeclampsia

 DEFINITION:

• Preeclampsia is a multisystem disorder of unknown etiology characterized by development of hypertension to the extent of 140/90 mm Hg or more with proteinuria after the 20th week in a previously normotensive and nonproteinuric woman

DIAGNOSTIC CRITERIA OF PREECLAMPSIA:

• Hypertension: An absolute rise of blood pressure of at least 140/90 mm Hg
• Calculation based on mean arterial pressure (MAP) as advocated by Page
• MAP=(Systolic pressure + (diastolic pressure × 2))/3
• If the previous blood pressure is not known or a rise in systolic pressure of at least 30 mm Hg, or a rise in diastolic pressure of at least 15 mm Hg over the previously known blood pressure is called pregnancy-induced hypertension
• Pitting edema over the ankles after 12 hours bed rest or rapid gain in weight of more than 1 lb a week or more than 5 lb a month in the later months of pregnancy
• Proteinuria:Presence of total protein in 24 hours urine of more than 0.3 g or more than or equal to 2+ (1.0 g/L)
• Test for protein in urine by multiple reagent strip (dipstick) as follows: Trace = 0.1 g/L; 1+ =0.3 g/L; 2+ = 1.0 g/L; 3+ = 3.0 g/L; 4+ = 10.0 g/L

PREDISPOSING FACTOR: 

ETIOPATHOGENESIS OF PREECLAMPSIA:

• HYPERTENSION:Endothelial dysfunction and intense vasospasm

Trophoblast Invasion and Uterine Vascular Changes:

• First trimester (10–12 weeks) endovascular trophoblasts invades up to decidual segments
• Second trimester(16–18 weeks) another wave of trophoblasts invades up to the myometrial segments
• Imbalance in prostaglandins
• Increased vascular sensitivity to angiotensin-II
• Deficiency of nitric oxide
• Endothelin-1 causes hypertension
• Inflammatory mediators:Cytokines derived from activated leukocytes cause endothelial injury
• Abnormal lipid metabolism:oxidative stress 

CLINICAL FEATURES:

• Slight swelling over the ankles
• Swelling may extend to the face, abdominal wall, vulva and even the whole body
• Headache —either located over the occipital or frontal region
• Disturbed sleep
• Diminished urinary output—Urinary output of less than 400 mL in 24 hours is very ominous
• Epigastric pain—acute pain  associated with vomiting, at times coffee color, is due to hemorrhagic gastritis
• Eye symptoms—Blurring, scotomata, dimness of vision or at times complete blindness
• Vision is usually regained within 4–6 weeks following delivery
• Abnormal weight gain>5 lb a month
• Decrease in  in GFR
• Rise of blood pressure
• There is no manifestation of chronic cardiovascular or renal pathology.
• Pulmonary edema—due to leaky capillaries and low oncotic pressure
• chronic placental insufficiency

COMPLICATIONS:

During pregnancy:

• Eclampsia (2%)
• Accidental hemorrhage
• Oliguria and anuria 
• Dimness of vision and even blindness
• Preterm labor
• HELLP syndrome
• Complete hydatidiform mole 
• Placental abruption
• Low maternal serum 25-hydroxyvitamin D
• Cerebral hemorrhage
• Acute respiratory distress syndrome (ARDS)

During labor:

• Eclampsia
• Postpartum hemorrhage 
• Affects Duration of latent phase of labour

Puerperium:

• Eclampsia — usually occurs within 48 hours
• Shock
• Sepsis

Fetal:

• IUD
• Intrauterine growth restriction
• Asphyxia
• Prematurity

INVESTIGATIONS:

Urine:

• Proteinuria
• Urine becomes solid on boiling (10–15 g/L)
• Hyaline casts, epithelial cells, few red cells

Ophthalmoscopic examination:

• Retinal edema
• Constriction of arterioles
• Alteration of normal ratio of vein: arteriole diameter from 3 : 2 to 3 : 1

Blood values:

• Serum uric acid level>4.5 mg/dL
• Serum creatinine > 1 mg/dL
• Thrombocytopenia 
• Abnormal coagulation profile
• ↑Hepatic enzyme

Antenatal fetal monitoring:

• Daily fetal kick count
• Doppler Ultrasonography for fetal growth and liquor pockets
• Cardiotocography
• Umbilical artery flow velocimetry
• Biophysical profile

MANAGEMENT: