Hypertensive Disorders in Pregnancy PDF

Hypertensive disorders in pregnancy Dr Lubna Batayneh The Hashemite University  Agenda Blood pressure in pregnancy and proper measurement Chronic hypertension in pregnancy Gestational hypertension Pre-eclampsia Eclampsia HELLP syndrome Postpartum m...

Hypertensive disorders in pregnancy Dr Lubna Batayneh The Hashemite University  Agenda Blood pressure in pregnancy and proper measurement Chronic hypertension in pregnancy Gestational hypertension Pre-eclampsia Eclampsia HELLP syndrome Postpartum management  Physiological cardiovascular changes in pregnancy ↑ Blood volume ↑ Cardiac output ↑ Heart rate ↓ Systemic vascular resistance ↓ Blood pressure Blood pressure falls gradually at first trimester, reaching a nadir around 22–24 weeks, rising again from 28 weeks, and reaching preconception levels by 36 weeks of gestation  How to measure blood pressure accurately? Five-minute rest before measurement, seated at 45-degree angle, arm at the level of the heart Avoid using automated devices (under-estimate BP) Use suitable cuff size (if circumference >=33 cm use large cuff) Keep the rate of deflation 2-3 mm/s Use Korotkoff 5 Avoid digit preference  Diagnosis of hypertension: Systolic BP > 140 mmHg OR Diastolic BP > 90 mmHg  Women who are pregnant and hypertensive have either: Chronic hypertension (with/ without superimposed pre-eclampsia) OR Pregnancy Induced Hypertension (PIH); which is further subdivided into: Non-proteinuric PIH (Gestational hypertension) Pre-eclapmsia  Chronic Hypertension The presence of hypertension before 20 weeks’ gestation OR Persistent hypertension beyond 6 weeks postpartum  Affects 1 - 5% of pregnant women Can be either: Essential (primary) hypertension Multifactorial with genetic and environmental contributions Secondary hypertension Renal disease is the most common cause in pregnant women  Pre-pregnancy counselling: 1. Counsel about potential complications in pregnancy 2. Address exacerbating factors and suggest lifestyle modifications (smoking cessation, weight loss, exercise, reduced alcohol intake, and low-salt diet) 3. Optimize blood pressure control 4. Screen for end-organ damage (e.g., creatinine levels) 5. Medication review Stop teratogenic agents (ACEIs, ARBs, Statins, Thiazide diuretics) and switch to alternative  Antenatal management –Medications: Stop teratogenic antihypertensive agents (ACEIs, ARBs, Thiazide diuretics) and switch to one of the following: 1. Labetalol –Non-selective adrenergic receptor blocker Avoid if asthmatic patient 1. Nifedipine –Calcium channel blocker 2. Methyldopa –Centrally acting α2-adrenergic agonist May cause tiredness, headache, depression, and occasionally hepatitis  Offer pregnant women with chronic hypertension Aspirin 75–150 mg once daily from 12 weeks (or before 16 weeks) to reduce the risk of pre-eclampsia  Antenatal management –Follow-up: Hypertension may improve in early pregnancy due to physiological changes and some women may stop their medication for several weeks. Continue antihypertensive treatment unless: sustained systolic blood pressure less than 110mmHg OR sustained diastolic blood pressure less than 70mmHg  Aim for a target blood pressure of 135/85 mmHg There’s an association between low diastolic BP in pregnancy and low birth weight therefore treatment should be reduced if diastolic BP is persistently < 80 mmHg  In women with chronic hypertension, schedule additional antenatal appointments based on the individual needs of the woman and her baby. This may include: Weekly appointments if hypertension is poorly controlled Appointments every 2 to 4 weeks if hypertension is well-controlled Appointments should include measurement of BP and urine dipstick to check for proteinuria (superimposed pre-eclampsia)  Maternal complications: 1. Superimposed pre-eclampsia : 20-30% Superimposed preeclampsia is defined as preeclampsia in the setting of maternal chronic hypertension 2. Deterioration of renal function if already affected prior to pregnancy, if renal function was normal before; pregnancy does NOT affect the course of the disease 3. Placental abruption: risk increased 3 folds  Fetal complications: 1. Intrauterine Growth Restriction (IUGR): 10-15% (risk is further increased if superimposed pre-eclampsia occurred) 2. Prematurity: 20-30%. This is frequently iatrogenic due to maternal or fetal indications 3. Stillbirth  Timing of birth: Timing of delivery should be guided by the severity of hypertension, the presence of proteinuria, and maternal and fetal wellbeing Women with chronic hypertension whom BP is stable < 160/110 should be delivered after 37 weeks unless there’s maternal or fetal indications If BP is sustained > 160/110 or there’s maternal or fetal compromise, a senior obstetrician can take the decision of a planned preterm birth (after a course of antenatal corticosteroids if time permits)  Postpartum management: Peak postpartum BP usually occurs at 3-5 days After delivery, aim for a target BP of < 140/90 mmHg In women with chronic hypertension who have given birth, measure blood pressure: Daily for the first 2 days after birth At least once between day 3 and day 5 after birth As clinically indicated after that  If a woman has taken methyldopa to treat chronic hypertension during pregnancy, stop within 2 days after birth and change to an alternative antihypertensive treatment (to avoid exacerbation of postnatal depression) Offer review at 6-8 weeks postpartum for appropriate contraception and future pre-pregnancy counselling Avoid estrogen containing contraception (combined) in women with hypertension due to their potential to exacerbate sodium retention and hypertension  Pregnancy induced hypertension Blood pressure >= 140 mmHg systolic OR >= 90 mmHg diastolic on two separate occasions at least four hours apart after 20 weeks gestation in a previously normotensive woman If systolic BP > 160 mmHg OR diastolic BP > 110 mmHg, can be diagnosed in a single occasion Final diagnosis only made postpartum (blood pressure normalizing within 6 weeks of delivery)  1. Gestational hypertension New hypertension presenting after 20 weeks of pregnancy without significant proteinuria. In women with gestational hypertension, a full assessment should be carried out Antenatal monitoring is needed to ensure that proteinuria does not develop, and pre-eclampsia becomes apparent (SCREENING) Risk of progression to pre-eclampsia is 20-30% Management Gestational hypertension Severe gestational hypertension Admission to hospital Do not routinely admit to hospital Admit, but if BP falls below 160/110 mmHg, then manage as for hypertension Antihypertensive Offer pharmacological treatment if BP Offer pharmacological treatment to all women remains above 140/90 mmHg Target blood pressure 135/85 mmHg or less 135/85 mmHg or less Blood pressure Once or twice a week (depending on Every 15 to 30 minutes until BP is less than measurement BP) until BP is 135/85 mmHg or less 160/110 mmHg Dipstick proteinuria Once or twice a week (with BP Daily while admitted testing measurement) Blood tests Measure full blood count, liver function Measure full blood count, liver function and and renal function at presentation and renal function at presentation and then then weekly weekly Fetal assessment - Offer fetal heart auscultation at every - Offer fetal heart auscultation at every antenatal appointment antenatal appointment - Carry out ultrasound assessment of - Carry out ultrasound assessment of the fetus the fetus at diagnosis and, if normal, at diagnosis and, if normal, repeat every 2 repeat every 2 to 4 weeks weeks if severe hypertension persists - Carry out a cardiotocography (CTG) - Carry out a CTG at diagnosis and then only if only if clinically indicated clinically indicated  Antihypertensive treatment: Consider Labetalol to treat gestational hypertension. Consider Nifedipine for women in whom Labetalol is not suitable, and Methyldopa if Labetalol or Nifedipine are not suitable. Base the choice on side-effect profiles, risk (including fetal effects) and the woman's preferences  Delivery and postpartum: If BP remains under 160/110 mmHg delivery between 37-39 weeks is appropriate (while monitoring closely for progression to severe hypertension, preeclampsia, and fetal growth restriction) If delivery becomes indicated < 37 weeks gestation, consider a course of antenatal corticosteroids prior to planned preterm birth (without delaying delivery) Gestational hypertension may be predictive of chronic hypertension later in life and is important in regard to patient counselling and preventative medical decisions  In women with gestational hypertension who have given birth, measure blood pressure: daily for the first 2 days after birth at least once between day 3 and day 5 after birth as clinically indicated if antihypertensive treatment is changed after birth.  In women with gestational hypertension who have given birth: continue antihypertensive treatment if required reduce antihypertensive treatment if their blood pressure falls below 130/80 mmHg  If a woman has taken methyldopa to treat gestational hypertension, stop within 2 days after the birth and change to an alternative treatment if necessary  Offer women who have had gestational hypertension and who remain on antihypertensive treatment, a medical review 2 weeks after delivery. Offer all women who have had gestational hypertension a medical review 6 to 8 weeks after delivery.  2. Pre-eclampsia Preeclampsia is diagnosed by elevated blood pressure and significant proteinuria after 20 weeks’ gestation in a patient known to be previously normotensive. Trophoblastic disease or multiple gestation can present with preeclampsia before 20 weeks’ gestation  Significant proteinuria: Use an automated reagent-strip reading device for dipstick screening for proteinuria If dipstick screening is positive (1+ or more), use spot (protein : creatinine) ratio or spot (albumin : creatinine) ratio to quantify proteinuria in pregnant women Gold standard test to quantify proteinuria: 24-hour urine collection Inconvenient so not routinely recommended  Thresholds for diagnosis of significant proteinuria: Spot Protein : Creatinine ratio >= 30 mg/mmol Spot Albumin : Creatinine ratio >= 8 mg/mmol 24-hour urine collection >= 300 mg  Risk factors: Nulliparity Multiple gestation Obesity (BMI >= 35) Medical disorders: chronic hypertension, pregestational diabetes, chronic kidney disease Autoimmune disease: SLE or APLS Personal or family History of preeclampsia Molar pregnancy Conception via assissted reproductive technologies Advanced maternal age (40 years)  Risk reduction: Low-dose Aspirin 75-150 mg starting before 16 weeks gestation until delivery for patients with one or more high risk factors OR two or more moderate risk factors  High risk Moderate risk Chronic hypertension Advanced maternal age > 40 years old Pregestational diabetes BMI >= 35 kg/ m2 Chronic kidney disease Nulliparity (primigravida) Systemic lupus erythematosus Interpregnancy interval > 10 years Antiphospholipid syndrome Multiple gestation Pre-eclampsia/Eclampsia in a previous pregnancy Family history of pre-eclampsia  Pathophysiology: It is clear that preeclampsia is a systemic disease, and the placenta is the root cause of preeclampsia. The proposed insult to the placenta is an immunologic alteration in trophoblastic function and reduction in trophoblast invasion. This in turn reduces vascular remodelling and physiological vasodilation of spiral arteries, reducing perfusion, and increasing velocity of blood in the intervillous space. This leads to both inflammation and endothelial damage and dysfunction.  Pre-eclampsia with severe features: Blood pressure of 160 mmHg systolic or 110 mmHg diastolic which is persistent Signs, symptoms, or lab values of severe preeclampsia with any elevated blood pressure  Signs and symptoms of severe preeclampsia include: 1. Cerebral or visual disturbances (e.g.; persistent headache, blurred vision, scotomata) 2. Persistent epigastric or right upper quadrant pain 3. Pulmonary edema Symptoms that can be seen with severe preeclampsia but are not diagnostic include nausea and vomiting, decreased urine output, hematuria, or rapid weight gain (5 lb or more in 1 week) An additional sign that does not establish a diagnosis but does need increased attention for preeclampsia is the rapid elevation of the patient’s blood pressure from baseline  Laboratory findings diagnostic of severe preeclampsia include: 1. Platelet count below 150 000 platelets per µL 2. Serum creatinine 90 micromol/litre or more, or a doubling of the patient’s baseline creatinine level 3. Liver enzyme (aspartate aminotransferase/alanine aminotransferase) elevation of more than double the upper limit of normal  Fetal findings associated with preeclampsia may include intrauterine growth restriction (IUGR), oligohydramnios, and other signs of uteroplacental insufficiency. However, none of these findings is diagnostic of preeclampsia or preeclampsia with severe features. Definitive management for gestational hypertension, preeclampsia, and eclampsia is delivery because the placenta is the insulting agent and removal of the placenta will lead to resolution of the disease process Management Pre-eclampsia Pre-eclampsia with severe features Admission to hospital Admit only if there are other clinical Admit, but if BP falls below 160/110 mmHg, concerns then manage Antihypertensive Offer pharmacological treatment if BP Offer pharmacological treatment to all remains above 140/90 mmHg women Target blood pressure Aim for BP of 135/85 mmHg or less Aim for BP of 135/85 mmHg or less Blood pressure At least every 48 hours, and more Every 15 to 30 minutes until BP is less than measurement frequently if the woman is admitted to 160/110 mmHg, then at least 4 times daily hospital while the woman is an inpatient, depending on clinical circumstances Dipstick proteinuria testing Only repeat if clinically indicated, for Only repeat if clinically indicated, for example, if new symptoms and signs example, if new symptoms and signs develop or if there is uncertainty over develop or if there is uncertainty over diagnosis diagnosis Blood tests Measure full blood count, liver function Measure full blood count, liver function and and renal function twice a week renal function 3 times a week  Fetal assessment in pre-eclampsia with/without severe features: Offer fetal heart auscultation at every antenatal appointment Carry out ultrasound assessment of the fetus at diagnosis and, if normal, repeat every 2 weeks Carry out a cardiotocography (CTG) at diagnosis and then only if clinically indicated  Management of pre-eclampsia without severe features (mild pre- eclampsia): At term: delivery, typically at 37 weeks or at time of diagnosis if after 37 weeks Preterm: optimal treatment prior to 37 weeks is usually expectant management  Thresholds for considering planned early birth could include: 1. Inability to control maternal blood pressure 2. Maternal pulse oximetry less than 90% 3. Progressive deterioration in liver function, renal function, haemolysis, or platelet count 4. Ongoing neurological features, such as severe intractable headache, repeated visual scotomata, or eclampsia 5. Placental abruption 6. Reversed end-diastolic flow in the umbilical artery doppler velocimetry, a non-reassuring cardiotocograph, or stillbirth.  Management of pre-eclampsia with severe features: urgent delivery after maternal stabilization is indicated Admission IV line, foley catheter insertion, strict intake/output recordings, fluid management IV antihypertensive agent (+/- MgSO4) Course of antenatal corticosteroids (should NOT delay urgent delivery) Laboratory assessments (repeat every 6 hours if still not delivered) Delivery when the mother is stable (usually by CS)  IV antihypertensive treatment: 1. Labetalol: 20 mg IV bolus, if persistently elevated: 40, 80, and 80 boluses up to a maximum dose of 220 mg, at 10-minute intervals 2. Hydralazine: 5 mg IV bolus, if persistently elevated: further 5 mg boluses up to a maximum dose of 15 mg, at 30-minute intervals (Colloid should be infused prior to treatment if the baby is undelivered to protect the uteroplacental circulation and prevent hypotension and fetal distress) If no IV access, use immediate release oral nifedipine  Magnesium Sulphate: Benefits: 1. Seizure prophylaxis (decrease the risk of eclampsia by more than 50%) 2. Neuroprotection (evidence of benefit from 24 weeks till 32 weeks) Dose: 4 gram bolus over 5-15 minutes, then 1 g/h infusion for 24 hours  ATTENTION!! MgSO4 has narrow therapeutic window –therapeutic range is 4 to 6 mEq/L Check serum magnesium level 4 hours after the loading dose and then every 6 hours as needed or if symptoms suggest magnesium toxicity  Patients are monitored hourly for signs and symptoms of magnesium toxicity: Loss of patellar reflexes (at 8 to 10 mEq/L) Respiratory depression or arrest (at 12 mEq/L) Mental status changes (at 12 mEq/L) followed by ECG changes and arrhythmias If magnesium toxicity develops: Stop magnesium sulphate Check the patient’s vital signs Check plasma levels Administer 1-g calcium gluconate IV over 3 minutes, and consider diuretics  Urine output and fluid management: Patients with preeclampsia are frequently hypovolemic due to third spacing and increased capillary permeability, these same abnormalities also increase their risk of pulmonary edema Limit maintenance fluids to 80 ml/hour unless there are other ongoing fluid losses (for example, haemorrhage) Urine output usually returns to normal about 12 to 24 hours after delivery  Fetal assessment and delivery: CTG should be done at diagnosis and continuous fetal heart monitoring is required if in labour Usually delivery by CS, unless mother and fetus are stable and cervix favourable then could try IOL by vaginal prostaglandins If the patient is being delivered by CS, keep in mind: Anaesthesia: GA can be dangerous as endotracheal intubation can exacerbate hypertension; regional anesthesia is preferred if time permits Platelet count: > 80 000 per µL needed for regional anaesthesia, also if GA is being used a minimum of 50 000 per µL is needed for CS  Maternal complications of pre-eclampsia: Renal failure Acute cardiac failure Pulmonary edema Thrombocytopenia Disseminated intravascular coagulopathy Cerebrovascular accidents  Fetal complications: Prematurity IUGR RDS IUFD  Postpartum: In women with pre-eclampsia who have given birth, measure blood pressure: At least 4 times a day while the woman is an inpatient Every 1 to 2 days for up to 2 weeks  If a woman has taken methyldopa to treat pre-eclampsia, stop within 2 days after the birth and change to an alternative treatment if necessary Measure platelet count, transaminases and serum creatinine 48 to 72 hours after birth Carry out a urinary reagent-strip test 6 to 8 weeks after the birth  Advise women who have had pre-eclampsia to achieve and keep a BMI within the healthy range before their next pregnancy (18.5 to 24.9 kg/m2). Advise women who have had pre-eclampsia that the likelihood of recurrence increases with an inter-pregnancy interval greater than 10 years.  Choose mode of birth for women with severe hypertension, severe pre-eclampsia or eclampsia according to the clinical circumstances and the woman's preference  Eclampsia Eclampsia should be the presumed diagnosis in obstetric patients with seizures and/or coma without a known history of epilepsy or other causes of seizures Occurs in about 1% of patients with pre-eclampsia  Eclampsia is an obstetric emergency that can occur antepartum, intrapartum, or postpartum The pathophysiology of eclamptic seizures is unknown but is related to arterial vasospasm and may occur when mean arterial pressure exceeds the capacity of cerebral autoregulation, leading to cerebral edema and increased intracranial pressure  Management: Appropriate management of ABCs (airway, breathing, and circulation) with measures taken to avoid aspiration Seizure control with 6-g MgSO4 IV bolus. If the patient has a seizure during or after the loading dose, an additional 2-g IV bolus of MgSO4 can be given. Treat seizures refractory to MgSO4 with IV phenytoin or a benzodiazepine (e.g., lorazepam). Treat status epilepticus with lorazepam. Patients with status epilepticus may require intubation to correct hypoxia and acidosis and to maintain a secure airway. Prevent maternal injury with padded bedrails and appropriate positioning. Control of severe hypertension  Delivery is indicated after maternal stabilization, and emergency cesarean delivery should always be anticipated in case of rapid maternal or fetal deterioration During acute eclamptic episodes, fetal bradycardia is common. It usually resolves in 3 to 5 minutes  HELLP Syndrome Hemolysis Elevated Liver enzymes Low Platelets Often presents with nonspecifi c complaints such as malaise, abdominal pain, vomiting, shortness of breath, or bleeding Hypertension is not always a clinical feature  Management is the same as for severe pre-eclampsia Transfusion of red cells, platelets, or factors may be required immediately prior to delivery depending on severity of anemia and thrombocytopenia Thank you!  References: 1. NICE guideline –Hypertension in pregnancy: diagnosis and management 2. Obstetrics and Gynaecology an evidence-based text for the MRCOG 3. THE JOHNS HOPKINS MANUAL OF GYNECOLOGY AND OBSTETRICS