Hypertension in Pregnancy

1. Hypertension in Pregnancy Presented by Dr A/Shakor MBChB GEZIRA UNIVERSITY -SUDAN Head of Anatomy Department Somali International University

3. OBJECTIVES • Be able to define hypertension in relationship to pregnancy. • Be able to classify hypertensive diseases in pregnant women. • Be able to list criteria for the diagnosis of preeclampsia. • Be able to list criteria for the diagnosis of severe preeclampsia/HELLP syndrome. • Be able to discuss current management considerations. • Understand and discuss the effects of hypertension on the mother and fetus.

4. Hypertension • Sustained BP elevation of 140/90 or greater. • Proper cuff size. • Measurement taken while seated. • Arm at the level of the heart. • Use Korotkoff sound.

6. Hypertensive Disease Associated with Pregnancy • Chronic Hypertension. • Gestational Hypertension. • Preeclampsia. • Eclampsia. • HELLP Syndrome.

7. Hypertensive Disease Associated with Pregnancy • Chronic Hypertension • Diagnosed before the 20th week or present before the pregnancy • Mild hypertension • > 140-180 mmHg systolic • > 90-100 mmHg diastolic • Gestational Hypertension • Preeclampsia • Eclampsia • HEELP Syndrome

8. Hypertensive Disease Associated with Pregnancy • Chronic Hypertension • Gestational Hypertension • Criteria • Develops after 20 weeks of gestation • Proteinuria is absent • Blood pressures return to normal postpartum • Morbidity is directly related to the degree of hypertension • Preeclampsia • Eclampsia • HEELP Syndrome

9. Hypertensive Disease Associated with Pregnancy • Chronic Hypertension • Gestational Hypertension • Preeclampsia • Criteria • Develops after 20 weeks • Blood pressure elevated on two occasions at least 6 hours apart • Associated with proteinuria and edema • May occur less than 20 weeks with gestational trophoblastic neoplasia • Eclampsia • HEELP Syndrome

11. Preeclampsia vs. Severe Preeclampsia Criteria for Preeclampsia Criteria for Severe Preclampsia • Previously normotensive woman • > 140 mmHg systolic • > 90 mmHg diastolic • Proteinuria > 300 mg in 24 hour collection • Nondependent edema • BP > 160 systolic or >110 diastolic • > 5 grof protein in 24 hour urine or > 3+ on 2 dipstick urines greater than 4 hours apart • Oliguria < 500 mL in 24 hours • Cerebral or visual distrubances (headache) • Pulmonary edema or cyanosis • Epigastric or RUQ pain • Evidence of hepatic dysfunction • Thrombocytopenia • Intrauterine growth restriciton (IUGR)

12. Risk Factors for Preeclampsia • Nulliparity • Multifetal gestations • Maternal age over 35 • Preeclampsia in a previous pregnancy • Chronic hypertension • Pregestational diabetes • Vascular and connective tissue disorders • Nephropathy • Antiphospholipid syndrome • Obesity • African-American race

14. Risk Factors

15. Hypertensive Disease Associated with Pregnancy • Chronic Hypertension • Gestational Hypertension • Preeclampsia • Eclampsia • Diagnosis of preeclampsia • Presence of convulsions not explained by a neurologic disorder • Grand mal seizure activity • Occurs in 0.5 to 4% or patients with preeclampsia • HEELP Syndrome

16. Hypertensive Disease Associated with Pregnancy • Chronic Hypertension • Gestational Hypertension • Preeclampsia • Eclampsia • HELLP Syndrome • A distinct clinical entity with: • Hemolysis, Elevated Liver enzymes, Low Platelets • Occurs in 4 to 12 % of patients with severe preeclampsia • Microangiopathichemolysis • Thrombocytopenia • Hepatocellular dysfunction

17. Morbidity and Mortality from Hypertensive Disease • Hypertension affects 12 to 22% of pregnant patients • Hypertensive disease is directly responsible for approximately 20% of maternal mortality in the United State

18. Pathophysiology • Vasospasm. • Uterine vessels. • Hemostasis. • Prostanoid balance. • Endothelium-derived factors. • Lipid peroxide, free radicals and antioxidants.

19. Pathophysiology • Vasospasm • Predominant finding in gestational hypertension and preeclampsia • Uterine vessels • Hemostasis • Prostanoid balance • Endothelium-derived factors • Lipid peroxide, free radicals and antioxidants

20. Pathophysiology • Vasospasm • Uterine vessels: • Inadequate maternal vascular response to trophoblastic mediated vascular changes • Endothelial damage • Hemostasis • Prostanoid balance • Endothelium-derived factors • Lipid peroxide, free radicals and antioxidants

21. Pathophysiology • Vasospasm • Uterine vessels • Hemostasis • Increase platelet activation resulting in consumption • Increased endothelial fibronectin levels • Decreased antithrombin III and α2-antiplasmin levels • Allows for microthrombi development with resultant increase in endothelial damage • Prostanoid balance • Endothelium-derived factors • Lipid peroxide, free radicals and antioxidants

22. Pathophysiology • Vasospasm • Uterine vessels • Hemostasis • Prostanoid balance • TXA2 promotes: • Vasoconstriction • Platelet aggregation • Endothelium-derived factors • Lipid peroxide, free radicals and antioxidants

23. Pathophysiology • Vasospasm • Uterine vessels • Hemostasis • Prostanoid balance • Endothelium-derived factors • Nitric oxide is decreased in patients with preeclampsia • As this is a vasodilator, this may result in vasoconstriction • Lipid peroxide, free radicals and antioxidants

24. Pathophysiology • Vasospasm • Uterine vessels • Hemostasis • Prostanoid balance • Endothelium-derived factors • Lipid peroxide, free radicals and antioxidants • Increased in preeclampsia • Have been implicated in vascular injury

26. Pathophysiologic Changes • Cardiovascular effects. • Hematologic effects. • Neurologic effects. • Pulmonary effects. • Renal effects. • Fetal effects.

27. Pathophysiologic Changes • Cardiovascular effects • Hypertension • Increased cardiac output • Increased systemic vascular resistance • Hematologic effects • Neurologic effects • Pulmonary effects • Renal effects • Fetal effects

28. Pathophysiologic Changes • Cardiovascular effects • Hematologic effects • Hypovolemia. • Elevated hematocrit • Thrombocytopenia • hemolytic anemia. • Low oncotic pressure • Neurologic effects • Pulmonary effects • Renal effects • Fetal effects

29. Pathophysiologic Changes • Cardiovascular effects • Hematologic effects • Neurologic effects: • Hyperreflexia • Headache • Cerebral edema • Seizures • Pulmonary effects • Renal effects • Fetal effects

30. Pathophysiologic Changes • Cardiovascular effects • Hematologic effects • Neurologic effects • Pulmonary effects • Pulmonary edema • Renal effects • Fetal effects

31. Pathophysiologic Changes • Cardiovascular effects • Hematologic effects • Neurologic effects • Pulmonary effects • Renal effects • Decreased glomerular filtration rate • Proteinuria • Oliguria • Acute tubular necrosis • Fetal effects

32. Pathophysiologic Changes • Cardiovascular effects • Hematologic effects • Neurologic effects • Pulmonary effects • Renal effects • Fetal effects: • Placental abruption • Fetal growth restriction • Oligohydramnios. • Fetal distress • Increased perinatal morbidity and mortality

33. Management: • The ultimate cure is delivery. • Assess gestational age. • Assess cervix. • Fetal well-being. • Laboratory assessment. • Rule out severe disease!!

34. Gestational HTN at Term • Delivery is always a reasonable option if term. • If cervix is unfavorable and maternal disease is mild, expectant management with close observation is possible.

35. Mild Gestational HTN not at Term: • Rule out severe disease • Conservative management • Serial labs • Twice weekly visits • Antenatal fetal surveillance • Outpatient versus inpatient

36. Indications for Delivery • Worsening BP. • Non-reassuring fetal condition. • Development of severe PIH. • Fetal lung maturity. • Favorable cervix.

37. Hypertensive Emergencies • Fetal monitoring. • IV access. • IV hydration. • The reason to treat is maternal, not fetal. • May require ICU.

38. Criteria for Treatment • Diastolic BP > 105-110 • Systolic BP > 200 • Avoid rapid reduction in BP • Do not attempt to normalize BP • Goal is DBP < 105 not < 90 • May precipitate fetal distress

39. Key Steps Using Vasodilators • 250-500 cc of fluid, IV • Avoid multiple doses in rapid succession • Allow time for drug to work • Maintain LLD position • Avoid over treatment

40. Acute Medical Therapy • Hydralazine • Labetalol • Nifedipine • Nitroprusside • Diazoxide • Clonidine

41. Hydralazine • Dose: 5-10 mg every 20 minutes • Onset: 10-20 minutes • Duration: 3-8 hours • Side effects: headache, tachycardia. • Mechanism: peripheral vasodilator

42. Labetalol • Dose: 20mg, then 40, then 80 every 20 minutes, for a total of 220mg • Onset: 1-2 minutes • Duration: 6-16 hours • Side effects: hypotension • Mechanism: Alpha and Beta block

43. Nifedipine • Dose: 10 mg , not sublingual • Onset: 5-10 minutes • Duration: 4-8 hours • Side effects: chest pain, headache, tachycardia • Mechanism: CA channel block

44. Clonidine • Dose: 1 mg po • Onset: 10-20 minutes • Duration: 4-6 hours • Side effects: unpredictable, avoid rapid withdrawal • Mechanism: Alpha agonist, works centrally

45. Nitroprusside • Dose: 0.2 – 0.8 mg/min IV • Onset: 1-2 minutes • Duration: 3-5 minutes • Side effects: cyanide accumulation, hypotension • Mechanism: direct vasodilator

46. Seizure Prophylaxis • Magnesium sulfate • 4-6 g bolus • 1-2 g/hour • Monitor urine output. • With renal dysfunction, may require a lower dose

47. Magnesium Sulfate. • Is not a hypotensive agent • Works as a centrally acting anticonvulsant • Also blocks neuromuscular conduction

48. Treatment of Eclampsia • Few people die of seizures • Protect patient • Avoid insertion of airways and padded tongue blades • IV access • MGSO4

49. THE FIRST THING TO DO AT A SEIZURE IS TO TAKE YOUR OWN PULSE!