Hypertension in Pregnancy Peter Bernstein, MD, MPH Associate Professor of Clinical Obstetrics & Gynecology and Women’s Health Albert Einstein College of Medicine/ Montefiore Medical Center

Introduction Hypertension - one of the most common medical complications of pregnancy Hypertension - one of the most common medical complications of pregnancy »Along with hemorrhage, complications of hypertensive disorders are a leading cause of maternal death ( ~ 15% of maternal deaths) »It is also a major cause of perinatal morbidity and mortality.

Definitions Chronic hypertension: Chronic hypertension: –A sustained BP > 140/90 that antecedes pregnancy or persists postpartum (beyond 6 weeks). HTN that is present before the 20th week of pregnancy may also be included as CHTN.

Definitions Preeclampsia Preeclampsia –Hypertension that develops as a consequence of pregnancy and regresses postpartum and is associated with proteinuria (> 300 mg./24 hrs.) –National High Blood Pressure Education Program Working Group on High Blood Pressure in Pregnancy, 2000

Preeclampsia (continued) Preeclampsia is highly suspected in the absence of proteinuria if one of the following is present: Preeclampsia is highly suspected in the absence of proteinuria if one of the following is present: –headache, vision changes, abdominal pain, abnormal labs Incidence: Incidence: –Nulliparous: 2-7% –Twin gestations: 14% –Previous preeclampsia: 18%

Severe Preeclampsia BP 160/100mm Hg recorded on at least two occasions measured at least six hours apart. BP 160/100mm Hg recorded on at least two occasions measured at least six hours apart. Proteinuria 5g/24 hours (3+ to 4+ on qualitative exams) Proteinuria 5g/24 hours (3+ to 4+ on qualitative exams) Oliguria <500ml in 24 hours or 20 ml/hr. Oliguria <500ml in 24 hours or 20 ml/hr. Rise in serum Creatinine to over 1.2 mg/dL. Rise in serum Creatinine to over 1.2 mg/dL. Cerebral or visual changes. Cerebral or visual changes.

Severe Preeclampsia (cont.) –Pulmonary edema or cyanosis. –Epigastric or right upper quadrant pain. –HELLP Syndrome –Fetal Growth Restriction –Oligohydramnios –Eclampsia: the presence of seizures in a patient with PIH and not attributable to other causes

Severe Preeclampsia: HELLP Syndrome A constellation of hematologic and hepatic manifestations in patients with PIH. A constellation of hematologic and hepatic manifestations in patients with PIH. –Hemolysis » Microangiopathic hemolytic anemia –Elevated Liver function tests »Elevated liver enzymes »Increased bilirubin –Low Platelets »Platelet count <100,000/mm3

Definitions Preeclampsia superimposed on chronic hypertension Preeclampsia superimposed on chronic hypertension –In women with CHTN and no proteinuria prior to 20 weeks, new onset proteinuria (>300mg./24hrs.) –In women with CHTN and proteinuria prior to 20 weeks, sudden increase in proteinuria or BP, fall in platelets (<100k/mm 3 ), or elevation of LFTs. –Occurs in ~25% of pregnancies of women with CHTN

Gestational Hypertension Hypertension detected at >20 weeks gestation in the absence of proteinuria Hypertension detected at >20 weeks gestation in the absence of proteinuria Incidence Incidence –Nulliparas: 6-12% –Multiparas: 2-4% Reclassified postpartum as: Reclassified postpartum as: –Transient Hypertension of Pregnancy if resolves by 12 weeks postpartum –Chronic Hypertension if does not resolve

Chronic Hypertension Often seen in patients who have other medical complications: obesity, diabetes, hyperlipidemia, cigarette smoking. Often seen in patients who have other medical complications: obesity, diabetes, hyperlipidemia, cigarette smoking. –Essential HTN – majority will have normal pregnancies. –Secondary HTN – parenchymal renal disease, pheochromocytoma, Cushing’s syndrome, hyperthyroidism, etc.

Chronic Hypertension If end-organ disease is present (renal, cardiac, cerebrovascular), there is an increased risk of morbidity and mortality. If end-organ disease is present (renal, cardiac, cerebrovascular), there is an increased risk of morbidity and mortality. –Maternal – superimposed preeclampsia, placental abruption, congestive heart failure –Fetal – intrauterine growth restriction, prematurity and fetal death

Preconception Care of CHTN Review the medical history: diagnosis and duration of hypertension, ongoing pharmacological treatment, known existence of organ damage or other compounding illnesses. Review the medical history: diagnosis and duration of hypertension, ongoing pharmacological treatment, known existence of organ damage or other compounding illnesses. Review obstetrical history. Review obstetrical history.

Preconception Care of CHTN Physical exam and laboratory evaluation Physical exam and laboratory evaluation »Urine analysis, urine culture/sensitivity, 24 hour urine for total protein and creatinine clearance »CBC »Diabetes screening »If the patient has severe hypertension, significant proteinuria or prior poor obstetric outcome more extensive tests may be offered.

Preconception Care of CHTN Optimize control with recommended medications. Optimize control with recommended medications. –Methyldopa (Aldomet): extensively studied in pregnant women, treatment of choice if needed. Central adrenergic inhibitor –Hydralazine: potent vasodilator, which acts directly on vascular smooth muscle. –Calcium channel blockers (Nifedipine): inhibits transmembrane calcium ion influx which causes vasodilation.

Antihypertensives –B-Adrenoreceptor blockers (e.g. atenolol, propranolol): possible fetal IUGR, neonatal respiratory depression, bradycardia and hypoglycemia –Angiotensin-converting enzyme inhibitors: not recommended for use in pregnancy –Thiazides diuretics: not recommended for use in pregnancy.

Pregnancy management-HTN Pregnancy management-HTN First trimester First trimester –Document EDC –Evaluate severity of hypertension and efficacy of medication if in use. –Baseline CBC, urine analysis, urine culture, 24- hour urine for total protein and creatinine clearance, consider LFTs. Repeat each trimester as indicated.

Pregnancy Management-HTN Medication Management Medication Management –Antihypertensive medication usage for mild chronic hypertension in pregnancy is controversial –Recommendations for therapy »Continue medication if started prior to pregnancy and BP is controlled. »Initiate antihypertensive medication if diastolic BP > mm Hg or systolic BP > mm Hg. »If the BP increases rapidly and persists diastolic >110mm Hg or is associated with proteinura, deteriorating renal function or IUGR, delivery recommended.

Pregnancy Management-HTN Antepartum surveillance recommended due to increased mortality and morbidity Antepartum surveillance recommended due to increased mortality and morbidity –Begin by 32 weeks EGA if there is renal disease, IDDM, cardiac dysfunction or if medication is used to manage the CHTN. »?NST, BPP, AFI-UA Dopplers, fetal growth

Pregnancy Management-HTN Superimposed preeclampsia is a concerning complication due to increased perinatal morbidity and mortality (Occurs in as many as 25% of CHTN pregnancies). Superimposed preeclampsia is a concerning complication due to increased perinatal morbidity and mortality (Occurs in as many as 25% of CHTN pregnancies). –Cannot rely on BP changes for diagnosis. –Follow new onset of proteinuria, thrombocytopenia, abnormal LFTs or generalized edema.

Pregnancy Management-HTN Indications for delivery: Indications for delivery: –superimposed preeclampsia –IUGR at term – nonreassuring fetal testing –consider if favorable cervix after 37 weeks EGA –completion of weeks of pregnancy in an otherwise uncomplicated patient

Preeclampsia-Diagnosis –Frequency: 2-10% of all pregnancies –Risk factors »CHTN »Chronic renal disease »Antiphospholipid syndrome »Diabetes »Multiple gestation »Nulliparity »Extremes of age

Preeclampsia Risk factors (cont.) Risk factors (cont.) –Hydatidiform mole –Previous history of preeclampsia –Changing paternity in successive pregnancies –Family history (inherited form, angiotensinogen gene T235) –FOB is the product of a preeclamptic pregnancy

Preeclampsia-Presentation Classic presentation: hypertension and proteinuria Classic presentation: hypertension and proteinuria BP elevation may be late. BP elevation may be late. Rarely develops before 20 weeks. If it does, consider the diagnosis of hydatidiform mole, antiphospholid syndrome, or SLE. Rarely develops before 20 weeks. If it does, consider the diagnosis of hydatidiform mole, antiphospholid syndrome, or SLE.

Preeclampsia Treatment: the only cure is delivery. Treatment: the only cure is delivery. »Differentiate between mild and severe preeclampsia. »Antepartum fetal assessment for well-being Daily fetal kick counts, NST twice a week, AFI weekly, growth scan q 2-3 weeksDaily fetal kick counts, NST twice a week, AFI weekly, growth scan q 2-3 weeks »Maternal BP monitoring, daily weight, serial laboratory studies »Consider glucocorticoid treatment for the fetus if preterm.

Preeclampsia-Management Induction indications Induction indications –Develops signs or symptoms of severe preeclampsia –Nonreassuring fetal status –Term

Preeclampsia-MgSO4 Use magnesium sulfate for seizure prophylaxis at time of labor or induction. Use magnesium sulfate for seizure prophylaxis at time of labor or induction. Bolus: 4-6g in 100ml of sterile water over min.Bolus: 4-6g in 100ml of sterile water over min. Rate: 2g/hourRate: 2g/hour Serum magnesium levels maintained between 4-7 mEq/LSerum magnesium levels maintained between 4-7 mEq/L Continue treatment for at least 24 hours after delivery.Continue treatment for at least 24 hours after delivery. Calcium gluconate, 1 g IV slowly over 2 minutes can be administered for toxic levels of MgSO4.Calcium gluconate, 1 g IV slowly over 2 minutes can be administered for toxic levels of MgSO4. Level 8-10 mEq/L – loss of patellar refluxLevel 8-10 mEq/L – loss of patellar reflux Level 12 mEq/L – respiratory arrestLevel 12 mEq/L – respiratory arrest

Severe Preeclampsia Due to increased risks for perinatal mortality and maternal morbidity and mortality, usually delivery is accomplished when the patient is diagnosed with severe disease. Due to increased risks for perinatal mortality and maternal morbidity and mortality, usually delivery is accomplished when the patient is diagnosed with severe disease.

Severe Preeclampsia If EGA < 34 weeks and the patient and fetus are stable, expectant management can be considered. If EGA < 34 weeks and the patient and fetus are stable, expectant management can be considered. –Maternal morbidity seen with observation Abruptio placentaAbruptio placenta EclampsiaEclampsia CoagulopathyCoagulopathy Renal failureRenal failure

Severe Preeclampsia MgSO4 seizure prophylaxis MgSO4 seizure prophylaxis –Continue treatment for at least 24 hours and there is observed improvement or resolution of thrombocytopenia and liver and renal function. –Antihypertensive medications if BP diastolic >110mm Hg or systolic >180mm Hg »Hydralazine IV 5-10 mg bolus q 20 min. »Labetalol 20 mg IV q min. (max 300 mg)

Preeclampsia-Prevention –The use of low-dose aspirin to prevent preeclampsia in nulliparous women has been studied. The incidence of preeclampsia was reduced, but no improvement in fetal or neonatal morbidity or mortality was seen. –Nutritional supplementation – calcium, magnesium, zinc: adequate outcome data showing improvement has not been documented.

Preeclampsia-Recurrence Patients are at increased risk for recurrent PIH in future pregnancies. The risk is greater based on the EGA and severity of the first pregnancy with PIH/preeclampsia. Patients are at increased risk for recurrent PIH in future pregnancies. The risk is greater based on the EGA and severity of the first pregnancy with PIH/preeclampsia. There is an association between PIH and a later diagnosis of CHTN. There is an association between PIH and a later diagnosis of CHTN.

Eclampsia The Most Common Cause of Peripartum Seizures The Most Common Cause of Peripartum Seizures –Can’t predict who will have seizures –Can’t rely on BP elevations. Approx. 20% of the patients who have eclampsia has normal BP. –Can’t rely on proteinuria. 10% of patients will have a seizure before overt proteinuria. –Neurologic tests are only useful for patients with atypical features. (Late postpartum seizures, persistent abnormalities in the mental status, focal neurological deficits)

Eclampsia-Treatment –Control of convulsions: magnesium sulfate –Correction of hypoxia and acidosis –Blood pressure control –Hydralazine –Magnesium sulfate is not administered to control BP. –Delivery after control of convulsions. Vaginal delivery is still attempted if not otherwise contraindicated.

HELLP Syndrome Liver Involvement in Preeclampsia Liver Involvement in Preeclampsia »Diagnosis –Differential diagnosis: acute fatty liver of pregnancy (AFLP), hepatitis, thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome, gallbladder disease, appendicitis, gastroenteritis. –In some populations, this variation of PIH can occur in 20% of women with severe preeclampsia. –Very high morbidity: placental abruption, acute renal failure, pulmonary edema, subcapsular liver hematoma.

HELLP Syndrome Treatment Treatment »The only cure is delivery. »Consider platelet transfusion for platelet count 50,000/mm3 if undelivered and surgical hemostasis will be needed. »Use of IV Dexamethasone may lessen severity and speed resolution Recurrence of HELLP in future pregnancies Recurrence of HELLP in future pregnancies »5% in patients with preexisting CHTN »3% in patient with normotensive patients

Conclusion Hypertensive disorders of pregnancy are frequently seen. Recognizing the diagnostic features and understanding the management of these illnesses will help to decrease the associated increased maternal and neonatal morbidity and mortality. Hypertensive disorders of pregnancy are frequently seen. Recognizing the diagnostic features and understanding the management of these illnesses will help to decrease the associated increased maternal and neonatal morbidity and mortality.