HYPERTENSIVE DISORDERS IN PREGNANCY

1. HYPERTENSIVE DISORDERS IN PREGNANCY SALWA NEYAZI Assisstent Prof. & Consultant OBG Pediatric & Adolescent Gynecology

2. 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 -1stpreg with new partner -multiple preg -obesity -black race -collagen vascukar disease -thrombophilias -extremes of reproductive age

3. MEASUREMENT OF BP • Use accurate mercury sphigmomanometer • Sitting position • Appropriate size cuff • Korotkoff sounds I & V (disappearance)

4. 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

5. PREOTEINURIA • Proteinuria indicate glomerular dysfunction • Definition: -urine protein ≥ 300 mg on 24 hrs collection -24 hrs urine should be considered if proteinuria ≥ 2+ on dipstick -urine protein/creatinine ratio under study OEDEMA & WT GAIN ARE NOT PART OF THE CURRENT DEFINITION

6. 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

7. 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

8. MATERNAL ADVERSE CONDITIONS VASCULAR /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

9. INITIAL EVALUATION • Identify risk markers • Clinical evaluation of the mother • Evaluation of the fetus • Lab investigations • Subsequent management

10. 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

11. 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

12. EVALUATION OF THE MOTHER • Hematologic -Bleeding -Petechiae • Hepatic -RUQ pain/ epigastric pain -Nausea & vomitting

13. 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

14. EVALUATION OF THE FETUS • Fetal movement • NST • U/S -growth (IUGR) -BPP -Doppler -AFV/ oligohydramnious

15. 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

16. SUPPORTIVE MANAGEMENT • Stress reduction -quiet environment -clear explanation of Rx plan -consistent confident team approach • Pain relief • Antiemetics • Minimize liver palpation

17. 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

18. ANTIHYPERTENSIVE AGENTS--ACUTE 1-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

19. ANTIHYPERTENSIVE AGENTS--ACUTE 2-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

20. 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

21. ANTIHYPERTENSIVE AGENTS - MAINTENANCE • GOAL -Without co morbid condition BP 130-155/80-105 -With comorbid condition BP 130-139/80-89 1-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/d 2-Βblockers/ LABETOLOL 100-600 bd-qid Max 1200/d 3-Calcium channel blockers/ NEFIDIPINE -intermediate release 20-40 mg/d Max 80 -extended release 20-60 ng/d Max 120 mg

22. 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

23. 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

24. 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

25. 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

26. 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

27. 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

28. 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

29. 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

30. 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)

31. 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

32. 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