Hypertension in pregnancy

AHMAD ALI KHAN

08-014

BATCH I

Hypertension :

High blood pressure is said to be present if bp is

persistently at or above 140/90 mmHg.

May belong to one of the following

Gestational hypertension (occurring solely because of pregnancy)

Chronic hypertension (hypertensive from before the pregnancy)

Chronic hypertension (incidentally becoming apparent first time in

pregnancy

Gestational hypertension

Pregnancy induced hypertension

(Gestational hypertension is usually defined as having a blood pressure higher than 140/90mm hg without the presence of protein in the urine and diagnosed after 20 weeks of gestation)

Pre eclampsia

(Pre-eclampsia is gestational hypertension (blood pressure greater than 140/90) plus proteinuria (>300 mg of protein in a 24-hour urine sample). Severe preeclampsia involves a blood pressure greater than 160/110, with additional medical signs and symptoms)

Eclampsia

(This is when tonic-clonic seizures appear in a pregnant woman with high blood pressure and proteinuria)

Pathophysiology

Disease of pregnancy.

Exact aetiology is unknown

According to the current concept it is a disease of wide spread

endothelial damage

Occurs from placental pathology and its signs are due to secondary

involvement of other organ system

PRIMARY PLACENTAL PATHOLOGY

two lesions have been identified

1- Lack of secondary wave of trophoblastic invasion:

Normally the spiral arteries undergo physiological changes

these are

cytotrophoblast of placenta that breaks down the endothelium, internal elastic lamina& muscular coat of vessel

these are replaced by fibrinoid converting the vessel to sinusoids.

In pre eclampsia only half to 2/3rd of arteries undergo these changes.

This leads to restriction in placental blood flow

which becomes evident with advancing gestation.

More over they remain sensitive to vasomotor stimulus.

2-Acute atherosis :

The second lesion is called acute atherosis. ,which is characterized by

aggregates of fibrin, platelets & lipid laden macrophages

It is seen in spiral arteries the basal arteries and the decidua parietalis

.

These lasions partly or completely block the Vessels

leading to ischaemia of fetal placenta giving rise to infarcts patchy

necrosis & intracellular damage to syncytiotrophoblast

Secondary influences :

Maternal effects:

the abnormal placentation& production of products of inflammation effect wide range of organs

Maternal organ involvement :

Cardiovascular system :

(rise in bp because of ↑ vascular resistance & may lead to severe hypertension)

Renal system:

first tubular dysfunction leading to hyperurecemia

then gromerular dysfunction leading to proteinuria exceeding 5 grams /24hrz.

Proteinuria leads to hypoalbumenaemia

this leads to lower colloid osmotic pressure & generalized edema,ascites,pleuraleffusion pulmonary & cerebral edema .

Liver:

periportal and subcapsular haemorrhage , periportal fibrin deposition

areas of infarction and necrosis

Excessive haemorrhage may lead to rupture shock and maternal death .

Blood :

activation of coagulation and fibrinolytic system.

In severe cases it may lead to DIC & microangiopathic haemolytic anemia

HELLP syndrome :

(haemolysis ,elevated liver enzymes and low platelet count)

Occurs in later part of pregnancy.

The common symptoms are epigastric or right hypochondral pain, nausea ,

vomiting and visual disturbance

Respiratory system :

pulmonary edema & adult respiratory distress syndrome

Fetal effects :

Malnourished

Growth restriction

May die in utero

Risk factors : May be maternal & fetal

MATERNAL :

Primigravidity

Age less than 20 & more than 35

Previous pre eclampsia & its family history

Obesity

Pregnancy with a new partner

Chronic hypertension

Diabetes

Chronic renal disease

Hypothyroidism

Migrane

Fetal / placental factors :

Large placenta

Prolonged pregnancy

Multiple pregnancy

Hydatidiform mole

Chromosome anomaly

Management :

The women is hypertensive when the bp is persistenly high at two consective readings when taken 4 or more hours apart.

To determine the type of hypertension & where it is preeclampsia the extict of the disease

The steps are:

History

Examination

Investigations (maternal & fetal)

maternal

↓

Proteinuria ( ↑300mg/24 hrs)

Renal function test (urea ↑7mmol/l & creatinine ↑100mmol/l indicate severe disease)

LFTs

Coagulation profile (platelet count, fibrinogen level, thrombin time & fibrinogen degradation products)

Fetal → ultrasound

FURTHER MANAGEMENT :

Hypertension alone

Hypertension with proteinuria

Hypertension with proteinuria and symptoms

Hypertension alone :

focus on antihypertensive therapy and salt intake

↓

Antihypertensive therapy

↓ ↓

emergency long term antihypertensives

↓ ↓

Hydralazine Methyl dopa

Nefidipine Diuretics

Labetalol etc

Salt intake :

Should consume salt to taste but refrain from added salt

Hypertension with proteinuria:

should be admitted to hosp on the same day

↓

Management in hospital

Daily observations ( urea, symptoms, kick count

chart etc )

Twice week observations ( cardiotocography twice a

week)

Weekly observations (uric acid, urea, creatinine, LFT,

ultra sound at 2 weeks interval)

Conservative management should be culminated in the favour of delivery when:

Pregnancy reaches term

Maternal bp Cannot be controlled

Platelet count falls below 50 ×109/L

Creatinine rises above 120mmol/L

Women develops symptoms

Evidence of liver damage

Urinary protein loss exceeds 3g/24 hrs

Fetus is seriously compromised

Hypertension with proteinuria & symptoms (fulminating preeclampsia)

:

↓

Management on following lines

Hospital admission

High level of care

Fluid management ( to avoid oliguria)

Drug therapy (prophylactic anti convulsants like magnesium

sulphate & antihypertensives)

Management of labour & delivery :

Mode of delivery

→ vaginal delivery is the route of choice

→ pre eclampsia at times makes vaginal delivery risky

→ while managing pre eclampsia one should have low

threshold for c sec

Induction of labour

→ spontaneous labour carries best outcome

→ prostaglandins must be used with caution & patient

must be watched

properly

Oxytocin

→used for induction & augmentation of labour

→may lead to myocardial failure in patients with compromised

cardiac function

Fetal monitoring

Intstrumental delivery (not an indication but can be used)

Caesarean section

→ choice of anesthesia is important as GA poses specific problems in

pre eclamptic patients.

Management of eclampsia :

Two phases :

General measures

Specific measures

General measures :

Placed flat in the left lateral position & tight clothes are loosened

Air ways , breathing & circulation is maintained

IV line is taken preferably with a wide bore needle on both sdes

Foley,s catheter is passed for comfort of patient & measuring output

Specific measures :

Anticonvulsant drugs ( Diazepam is drug of choice,Mg sulpate & phenytoin to prevent recurrence

Diazepam ( 10mg IV initially. Dose is repeated with every fit to a total of 50mg)

Magnesium sulphate

↓

Loading dose of 4g given IV over 4 minutes & 10g IM(5g each buttock). Dose of 2g IV over 2 min is repeated if convulsions persist after 15 min . followed by maintainence dose of 5g IM every 4 hrs on alternate buttock

Phenytoin ( IV dose of 18mg/kg at rate of 50 mg /min

Antihypertensive therapy

IV labetalol & Hydralazine

Dilivery :

After seizures & hypertension are controlled fetal well being can be assessed & delivery is made

C section is recommended in the following

↓

all deeply unconscious patients until delivery is imminent

uncooperative patients due to restlessness

vaginal delivery is unlikely to occur within 6-8 hrs of first fit

obstetrical indication for C section

fetal distress

Thank you !!!