HYPERTENSIVE DISORDERS IN PREGNANCYSALWA NEYAZI

Assisstent Prof. & Consultant OBG

Pediatric & Adolescent Gynecology

INCIDENCE

5-8% of pregnancies 1/3 will have proteinuria A leading cause of direct maternal mortality -(It is the leading cause of DMM in CANADA with

PE) -Increased mortality risk in older gravidas Majority nulliparous Other risk factors: -peexisting HPT -renal disease -CVD -DM -1st preg with new partner -multiple preg -obesity -black race -collagen vascukar disease -thrombophilias -extremes of reproductive age

MEASUREMENT OF BP

Use accurate mercury sphigmomanometer

Sitting position

Appropriate size cuff

Korotkoff sounds I & V (disappearance)

DEFINITIONS

HPT Diastolic BP ≥ 90 based on the average

of 2 measurements taken on the same arm > 5 min apart after 10 min of rest

Severe HPT - Diastolic ≥ 110 on single measurement -Systolic ≥ 160 Incremental rise 30/15 is not criterion for

Dx

PREOTEINURIA

Proteinuria indicate glomerular dysfunction Definition: -urine protein ≥ 300 mg on 24 hrs

collection -24 hrs urine sho uld be considered if

proteinuria ≥ 2+ on dipstick -urine protein/creatinine ratio under study

OEDEMA & WT GAIN ARE NOT PART OF THE CURRENT DEFINITION

C LASSIFICATIONS OF HYPERTENSIVE DISORDERS IN PREGNANCY Preexisting HPT (prepregnancy or≤20wks gestation) -With comorbid conditions -With preeclampsia Gestational HPT ≥ 20 wks gestation -With comorbid conditions -Preeclampsia

PREECLAMPSIA

Preexisting HPT with -Resistent HPT and/or -New or worsening proteinuria

and/or -one or more adverse conditions Gestational HPT with -New proteinuria and/or -one or more adverse conditions

MATERNAL ADVERSE CONDITIONSVASCULAR /PULMONARY

-Diastolic BP ≥110

-Pulmonary edema

-Chest pain

-Shortness of breath

RENAL

-Proteinuria > 3 gm/24 hrs

-Oliguria <500 ml/24 hrs

-Serum albumin < 18 g/L

-elevated serum creatinin

Hepatic

-elevated liver enzymes

-RUQ pain/ epigastric pain

-severe nausea & vomiting

Hematologic

-decreased platelets <100,000/100X10⁹/L

-DIC

HELLP syndrome

-Hemolysis

-elevated liver enzymes

-low platelets

CNS-

-seizures

-frontal headache

- visual disturbances

FETAL

-IUGR

-oligohydramnious

-abnormal dopller

-IUFD

INITIAL EVALUATION

Identify risk markers Clinical evaluation of the mother Evaluation of the fetus Lab investigations Subsequent management

RISK MARKERS

Maternal age >40 Previous PET Antiphospholipid antibodies Preexisting medical conditions BMI>35 Family Hx of PET Booking systolic BP≥130 or diastolic

BP≥80 Interpregnancy interval >10 years Multiple gestation

EVALUATION OF THE MOTHER

BP -Assess severity (severe>160/110) -High BP related to CVA not seizures CNS -Presence & severity of headache -Visual disturbance: blurring or scotoma

-Tremors, irritability, hyperreflexia, somnolence -Nausea & vomitting

EVALUATION OF THE MOTHER

Hematologic -Bleeding -Petechiae Hepatic -RUQ pain/ epigastric pain -Nausea & vomitting

EVALUATION OF THE MOTHER (lab) CBC----Hb, PLT PT, APTT, INR, fibrinogen Bilirubin ALT, AST, LDH, ALBUMIN Glucose. amonia to R/O acute fatty

liver Proteiuria (dipstick, 24 hr collection) Urea, creatinin, uric acid

EVALUATION OF THE FETUS

Fetal movement NST U/S -growth (IUGR) -BPP -Doppler -AFV/ oligohydramnious

MANGEMENT GOALS

Prevention of adverse maternal outcomes (organ damage, seizures, CVA,death) Prevention of adverse fetal complications (abruption, IUFD, IUGR) Symptomatic support Delivery is the definitive treatment Deliver when: 1-G HPT is associated with adverse

conditions, regardless of gestational age 2- At or near term

SUPPORTIVE MANAGEMENT

Stress reduction -quiet environment -clear explanation

of Rx plan -consistent

confident team approach Pain relief Antiemetics Minimize liver palpation

ANTIHYPERTENSIVE THERAPY

Minimize the risk of CV A/ death

It is unclear whether antihypertensive therapy for mild-moderate HPT (diastolic 90-105) is beneficial

Gain time for further assessment -Facilitate vaginal delivery if possible -Prolong gestation if premature & appropriate

ANTIHYPERTENSIVE AGENTS--ACUTE1-CALCIUM CHANNEL BLOCKERS NEFIDIPINE

-PO / direct relaxation of the vascular smooth muscle

* Immediate release ---(Adalat) -5-10 mg swallowed / repeat in 30 min if no

response -may cause sudden drop in BP & fetal distress -reports of MI & CVA in the general population—

should be avoided in patients at risk * Intermediate acting ----(Adalat PA) - 10 mg PO repeat dose at 30-45 min if no

response -Onset of action in 90 min

ANTIHYPERTENSIVE AGENTS--ACUTE2-B –BLOCKERS Labetalol -10-20 mg IV over 2 min q 10-30

min up to 300 mg -onset of action in 5-10 min -Max action 30 min -IV infusion 1-2 mg /min --------

increase by 1mg q 15 min Max 4mg/min

ANTIHYPERTENSIVE AGENTS--ACUTE 3-ARTERIOLAR DILATORS Hydralazine -Should not be the first choice agent -A metanalysis showed that it is associated with -more adverse outcomes including:

abruption, fetal distress, low APGAR, CS & oliguria - it is less effective in BP control -onset of action in 5-10 min/ Max action 30 min -5-10 mg IV q 20 min -Infusion 0.5-10 mg/hr

ANTIHYPERTENSIVE AGENTS - MAINTENANCE

GOAL-Without co morbid condition BP 130-155/80-105-With comorbid condition BP 130-139/80-891-Centrally acting agents/ α METHYL-DOPA - Long Hx of safe use in pregnancy -drug of choice for essential HPT -500-1000 mg bd-qid Max 3000 mg/d2-Β blockers/ LABETOLOL 100-600 bd-qid Max 1200/d3-Calcium channel blockers/ NEFIDIPINE -intermediate release 20-40 mg/d Max 80 -extended release 20-60 ng/d Max 120 mg

FLUID MANAGEMENT

Monitor urine output /hourly intake output Total IV intake should not exceed 80-125

ml/hr In case of oliguria <15 ml/hr -follow serum creatinine -watch for magnesium toxicity -consider a small fluid bolus -consultation if persistent Judicious fluid adminstration Beware of pulmonary edema

SEIZURES PROPHYLAXIS

Difficult to predict who will seize Not directly related to the degree of

HPT or the level of proteinuria Mg SO4 is the agent of choice for

seizures prophylaxis in PET or for Rx of Eclampsia

-Dosage-4 gm IV followed by 1-2 g/hr-Do not use Diazepam or Phenytoin

unless Mg SO4 is contraindicated

MgSO4-OVERDOSE

Close observation for toxicity-Weakness, respiratory paralysis,

somnolence, heart block-High risk- renal failure, oliguria

ANTIDOTE Stop MgSO4 infusion 10% Calcium gluconate 10 ml IV over

3 min

MANAGEMENT OF ECLAMPSIA

Call for help Maternal lateral position Protect the airway MgSO4 Post-seizure: oxygen, vital signs,

fetal survillance Assess for evidence of abruption

TRANSPORT

Consider if resources limited & maternal/ fetal condition permits

-maternal BP & symptoms stable

-fetal status reassuring D/W receiving centre & Pt/ family Antihypertensive agent if indicated MgSo4 if indicated

WHEN TO DELIVER ?

Gestational HPT at or near term Gestational HPT with adverse

conditions irrespective of gestational age

-Mild IUGR alone is not an indication for

delivery -Role for prolonging pregnancy

with significant prematurity in a facility with sufficient resources

DELIVERY THE CURE

Timely delivery minimizes morbidity & mortality

Stabilize mother before delivery Delay delivery to gain fetal maturity and

allow for transfer only when fetal & maternal condition allows

Gestational HPT is a progressive disease Expectant management is potentially

harmful in presence of severe disease or suspected fetal compromise

PERI & POST PARTUM MANAGEMENT Gestational HPT may present or worsen after delivery Eclampsia 50 % before labor 25% in labor 25% early postpartum rarely 2 days or more after delivery Mg SO4 should be continued for the first 24 hrs

postpartum in high risk Pt Avoid abrupt drop in BP---aim for 80-100 diastolic Avoid fluid overload Epidural analgesia is favored in the absence of low

platelets or coagulopathy Multidisciplinary approach Patient must be monitored postpartum Can be discharged if BP remains< 160/100 for at least

24 hrs

PREVENTION

ASA -low dose -small role in the prevention of early onset (<34

wks) gestational HPT with proteinuria - delay the onset of proteinuria- Reduce the risk of severer HPT (HELLP, IUGR,

antiphospholipid syndrome ) Calcium supplement (1-2 gm Ca carbonate/day)-decrease the risk of HPT in preg in women who are

considered high risk for gestational HPT & in communities with low Ca intake

Antioxidants (Vit C, E) are not beneficial & may be harmful (increased risk of prematurity)

CONCLUSION

Gestational HPT with proteinuria & adverse condition is an OB Emergency

Multidisciplinary approach for management Prompt recognition & stabilization of the

mother & fetus are important The cure is delivery Timing of delivery is based on -Severity -Fetal maturity &

wellbeing -Maternal status

CONCLUSION

Antihypertensive Rx is used to prevent CVA not seizures

No evidence that antihypertensive Rx for mild –moderate HPT improves perinatal outcome

Magnesium Sulfate is the drug of choice for prevention & treatment of Eclampsia