Pregnancy Induced Hypertension
(Pre-eclamsia) (Pre-eclamptic Toxemia)
What is pregnancy induced hypertension?
List the signs of impending eclampsia
Explain the management of a pregnant woman at term with severe pre-eclmpsia
Definition
Pregnancy Induced Hypertension
A potentially dangerous complication of pregnancy characterized by high blood pressure in a woman with previously normal BP.
After 20 weeks of gestation
BP greater than 140/90 mm Hg on two separate occasions more than 6 hours apart
Without proteinuria
Preeclampsia
Gestational hypertension + Proteinuria (more than 300 mg of protein in urine collected in 24 hours
Eclampsia
Tonic and clonic seizures which appear in a pregnant woman with high blood pressure and proteinuria
Risk Factors
Maternal causes
Obesity
Age 35 years or more
Past history of diabetes mellitus, hypertension and renal disease.
Adolescent pregnancy
New paternity
Thrombophilias
Having donated kidney
Pregnancy : Multiple gestation (twins or triplets etc)
Placental abnormalities - Hyperplacentosis : excessive exposure to chorionic villi Placental ischaemia
Family history: Family history of preeclampsia
Signs and Symptoms of PIH
High Blood Pressure
Swelling of hands and feet
Protein in urine
Signs and Symptoms of impending eclampsia
Rapid weight gain caused by a significant increase in body fluid (generailsed oedema) Sudden weight gain over 1 or 2 days Sudden and new swelling in face, hands, and eyes (some feet and ankle swelling is normal during pregnancy.)
Abdominal pain especially in the upper right side, epigastrium, vomiting, right upper quadrant tenderness
Severe headaches
Change in reflexes
Reduced urine or no urine output
Dizziness
Excessive vomiting and nausea
Visual disturbances : Blurry vision, flashing lights, and floaters
Blood pressure greater than 140/90.
recently developed hypertension > or equal to 170/110 mmHg with proteinuria > 1 gram/24 hours or a rapid rise in blood pressure
pulmonary oedema
clonus and increased tendon refexes
HELLP syndrome
Convulsions due to Eclampsia
Can occur regardless of the severity of hypertension
Are diffcult to predict, but rarely occur without increased tendon refexes, headache or visual changes
Are tonic–clonic and resemble grand mal convulsions of epilepsy
May recur frequently, as in status epilepticus, and may be fatal
Will not be observed if the woman is alone
May be followed by coma that lasts for minutes or hours depending on the frequency of convulsions
Occur after childbirth in about 44% of cases, usually but not always within the first 24 hours after birth. The longer the gap between delivery and a fit, the more likely the diagnosis is to be a condition other than eclampsia (e.g. cerebral venous thrombosis).
Management of a Pregnant Woman at Term with Severe Pre-eclmpsia
MgSO4 to prevent seizures
Antihypertensives to control BP : BP should not be lowered suddenly; it will impair organ perfusion and result in maternal and fetal morbidity -
Drugs preferred : Labetalol orally in doses of 100-400 mg 8-12 hrly / Methyl dopa 250-500 mg 6-8 hrly / Nifedipine 10-20 mg bd or tds / Hydralazine 10-25 mt 12 hrly / IV or oral furosemide, oral thiazide. If very severe MgSO4
Delivery if cervix is ripe. Induction or Caesarian section
Indications for delivery : BP 160/110, proteinuria > 5 gm in 24 hours urine
Trying to continue pregnancy in severe pre-eclampsia will invite disaster
GA > 37 weeks → Deliver
GA < 32 and 36 weeks → periodic evaluation by NST, Lab, USGM and CE
Monitoring with uterine, umbilical & MCA doppler, UA utero-placental circulation, Umb A : Placento-umbilical circulation, weekly doppler, NST & MBBP twice weekly to assess fetal well-being, RFTs : serum uric acid, BUL, serum creatinine, LFTs, fibrinogen levels (abruption)
Antihypertensives used in pregnancy
Diuretics :: Furosemide, Chlorothiazide
Vasodilators : Labetalol, Nifedipine, Prazosin, Hydralazine
Drugs that decrease Cardiac Output : Betablockers, propranalol
Centrally acting drugs : Methyldopa
Contraindicated Antihypertensive Drugs in Pregnancy
ACE inhibitors
Angiotensin receptor antagonists
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