PRE-ECLAMPSIA Obstetrics and - PowerPoint Presentation

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PRE-ECLAMPSIA

Obstetrics and

Anaesthetics

Meeting Oct 2013

Dr

Sarah

Pixton

O&G Registrar

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INCIDENCE WORLDWIDE

Pre-

eclampsia

(PE)

is a multisystem disease that occurs in 2 to 8% of pregnant women and is a leading cause of maternal and

perinatal

morbidity and mortality

.

Eclampsia

affects 1 in 2000 pregnancies with a 2% mortality rate and a 35% rate of significant complication

.

HELLP

complicates 1 in 500 pregnancies

Worldwide

, PE is responsible for approximately 50,000 maternal deaths

annually.

Worldwide, 10 to 15 percent of direct maternal deaths (

ie

, resulting from obstetric complications of pregnancy) are associated with preeclampsia/

eclampsia

In the UK- The

Confidential Enquiries reveal that deaths from pre-

eclampsia/eclampsia

have been reduced from 11.9/million maternities in 1985–1987 to 7.0/million maternities in 2000–2002, when there were 14 deaths

.

Nine women died from cerebral causes, with substandard care in 50% of cases

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IN AUSTRALIA…

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IN AUSTRALIA…

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CLASSIFICATION OF HYPERTENSION IN PREGNANCY

Preeclampsia

(

incl.

eclampsia

and HELLP)

2) Chronic Hypertension

3) Preeclampsia

superimposed on

Chronic Hypertension

4) Gestational

Hypertension

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DIAGNOSIS1)Pre-eclampsia is defined as new onset of hypertension(≥140

/90)

after 20 weeks gestation with

proteinuria

( 0.3g/24hr),

in a previously

normotensive

woman

2)Chronic

/

pre-existing

hypertension is defined

as BP (

≥140/90)

that antedates pregnancy or is present before the 20th week of pregnancy (on at least two occasions) or persists longer than 12 weeks postpartum

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DIAGNOSIS3)Superimposed preeclampsia is defined by the new onset of proteinuria

after 20 weeks of gestation in a woman with chronic/preexisting hypertension.

4)Gestational

hypertension refers to hypertension without

proteinuria

or other signs/symptoms of preeclampsia that develops after 20 weeks of

gestation

and

resolves

by 12 weeks post partum

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PATHOPHYSIOLOGYAbnormalities of the placental vasculature (In

PE

, there is an improper remodeling of spiral arteries during

placentation

)

Relative placental

underperfusion/ischaemia

Release of

antiangiogenic

factors into maternal circulation

Systemic endothelial dysfunction

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In pre-eclampsia…

Aspirin level of action

Imbalance between vasodilator mediators (prostaglandin, NO) and vasoconstrictor mediators (

thromboxane

) results in endothelial dysfunction

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Under normal conditions, the remodeling of maternal spiral arteries is favoured by high availability of nitric oxide (NO)

In preeclampsia, there is an improper remodeling of spiral arteries during placentation causing endothelial dysfunction

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CLINICAL FEATURES

Cardiopulmonary

Hypertension

is generally the

earliest finding

Intravascular volume and

oedema

(intravascular

vol

is reduced likely due to vasoconstriction).

Oedema

(may represent overfilling) facial

oedema

Cardiac function

myocardium not affected directly by PE. high

afterload

in preeclampsia

Pulmonary

oedema

Multifactorial

-

causes of pulmonary edema

incl

capillary leak, left heart failure, and iatrogenic volume overload

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CLINICAL FEATURESRenal

Proteinuria

: It

is due, in part, to impaired integrity of the

glomerular

barrier and altered tubular handling of filtered proteins (

hypofiltration

) leading to increased protein

excretion

Renal

function:

GFR decreases by 30-40% 

Rising

Creatinine

and

oliguria:

ie

, urine output <500 mL/24 hours,

indicates severe

disease and results from

renal vasoconstriction and

sodium retention

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CLINICAL FEATURES

Haematologic

most common coagulation abnormality in preeclampsia is

thrombocytopenia.

Microangiopathic

endothelial injury and activation result in formation of platelet and fibrin thrombi in the

microvasculature.

Accelerated

platelet consumption leads to

thrombocytopenia

immune

mechanisms may also play a role

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CLINICAL FEATURESHepaticReduced

hepatic blood flow can lead to ischemia and

periportal

hemorrhage.

The

clinical manifestations of hepatic dysfunction include right upper quadrant or

epigastric

pain, elevated

transaminase

levels,

coagulopathy

, and, in the most severe cases,

subcapsular

hemorrhage or hepatic

rupture.Epigastric

pain is one of the cardinal symptoms of severe preeclampsia

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CLINICAL FEATURES

Neurological

 CNS manifestations

of

PE include

headache, visual symptoms, and

hyperreflexia

with

sustained ankle

clonus

Visual symptoms

are caused, at least in part, by constriction of retinal arteries. Symptoms include blurred vision, flashing

lights

and

scotomata

Seizures

in a

preeclamptic

woman signify a change in diagnosis to

eclampsia

Stroke

leading to death or disability is the most serious complication of severe preeclampsia/

eclampsia

Histopathologic

correlates include hemorrhage,

petechiae

, cerebral edema,

vasculopathy

, ischemic brain damage,

microinfarcts

, and

fibrinoid

necrosis

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CLINICAL FEATURES

Chronic

placental

hypoperfusion

results in

fetal growth restriction and

oligohydramnios

.

P

reterm

delivery

is a secondary result of fetal or maternal

complications

Abruptio

n

is infrequent (less than 1 percent) in women with mild preeclampsia, but has been reported in 3 percent of those with severe

disease

Increased

resistance in the placental vasculature is also reflected by rising Doppler indices of the umbilical artery

Fetus and Placenta

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CLINICAL FEATURES OF SEVERE PEsymptoms of :

severe headache

visual disturbance

epigastric

pain and/or

vomiting

dyspnoea

./

retrosternal

chest pain

confusion

signs

of

:Hypertension > 160/110Clonus (>3 beats)

papilloedema

L

iver

tenderness

Severe

proteinuria

>5grams/24hrHELLP syndrome

platelet

count falling to below

100

abnormal

liver enzymes (ALT or AST rising to above 70

iu/l

)

Elevated

creatinine

Fetal compromise- IUGR,

Oligohydramnios

, Abnormal flows

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ANTENATAL MANAGEMENT

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PREVENTIONIn the clinical practice, there is currently no reliable screening method in the first trimester of pregnancy with sufficient accuracy to identify women at high risk of developing pre-

eclampsia

, and only two interventions are strongly recommended by the World Health Organization for prevention of pre-

eclampsia

:

high dose calcium

supplementation in all women

at risk or with

low dietary calcium intake and

low-dose aspirin

.

Delivery is the only known cure.

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CLASP

The Collaborative Low·dose Aspirin Study in Pregnancy (CLASP) was performed from 1988-1993 as a randomized, double-blind, placebo-controlled trial of low-dose aspirin for the prevention or treatment of pre-eclampsia and /or fetal growth retardation.

Women between 12 and 32 weeks of pregnancy received a daily dose of 60 mg of aspirin or matching placebo until delivery if they were thought to be at higher than average risk of developing severe preeclampsia.

A total of 9364 women from 213 centers in 16 countries were randomized.

The impact of low-dose aspirin on the prevention of preeclampsia and its sequelae was smaller in CLASP than in the earlier reports possibly due to the inclusion of relatively low-risk patients in the CLASP- trial.

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CLASP Results

The prophylactic use of aspirin was associated with a decrease of

12%

in

the incidence of

proteinuric

preeclampsia

, but the reduction was not statistically significant.

No

significant effect on

birth weight or stillborn rate was

detected.

Aspirin did, however, significantly reduce the likelihood of preterm delivery (19.7% aspirin

vs 22.2%

control)

There was a significant trend (

p

= 0.004) towards progressively greater reductions in

proteinuric

pre-

eclampsia

the more preterm the delivery.There was no evidence of a therapeutic effect of low-dose aspirin

.

Finally

, CLASP provided support with regard to the safety of aspirin for the pregnant woman and her

baby

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From the NICE Guidelines..

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CALCIUM SUPPLEMENTATION

Calcium supplements (1.5-2g per day)

has been evaluated for prevention of hypertensive disorders of pregnancy

.

In a systematic

review of 13 randomized trials

(including >15,000 women), the

effects of calcium supplementation on development of pregnancy-related hypertensive

disorders was assessed.

It appeared to approx halve the risk of PE (RR 0.45, 95% CI 0.31-0.65), to reduce the risk of preterm birth (RR 0.76, CI 95% 0.60-0.97), and to reduce the outcome of “ maternal death or serious morbidity” ( RR 0.80, 95% CI 0.65-0.97)

There were no harms identified

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CURRENTLY NOT RECOMMENDED..Other pharmaceutical agents

Do

not use the following to prevent hypertensive disorders during pregnancy

:

•

nitric oxide donors • progesterone • diuretics • low molecular weight heparin

.

Nutritional supplements

Do

not recommend the following supplements solely with the aim of preventing hypertensive disorders during pregnancy

:

•

magnesium • folic acid • antioxidants (vitamins C and E) • fish oils or algal oils •

garlic.

Diet

Do

not recommend salt restriction during pregnancy solely to prevent gestational hypertension or pre-

eclampsia

.

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RECURRENCE

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Thank you

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REFERENCESDiagnosis, pathophysiology and management of pre-

eclampsia

: a

review

.

Susana

Machado, Marta

Neves

,

Luís

Freitas

,

Mário

Campos. Port

J

Nephrol

Hypert

2013; 27(3): 000-

000

Pre

-eclampsia

Sibai

,

Baha;Dekker

,

Gus;Kupferminc

, Michael

The Lancet; Feb 26-Mar 4, 2005; 365, 9461;

ProQuest

pg. 785

NICE Guidelines

: Hypertension

in

pregnancy :the

management of hypertensive disorders during

pregnancy. Revised Jan 2011

Up to Date

: Preeclampsia Clinical features and Diagnosis

www.somanz.org/

guidelines

-

Guidelines for the Management of Hypertensive Disorders of Pregnancy

2008

www.aihw.gov.au

- Statistics

Maternal deaths in Australia 2003-

2005

Calcium supplementation during pregnancy for preventing hypertensive disorders and related

problems.AUHofmeyr

GJ,

Lawrie

TA,

Atallah

AN,

Duley

LSO. Cochrane

Database

Syst

Rev. 2010;