hypertensive pregnancy disorders Flashcards
Gestational hypertension
Gestational hypertension: pregnancy-induced hypertension with onset after 20 weeks gestation
Defined as a systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg on 2 separate measurements at least 4 hours apart
Asymptomatic hypertension Nonspecific symptoms (e.g., morning headaches, fatigue, dizziness)
Chronic hypertension
Chronic hypertension: hypertension diagnosed < 20 weeks gestation or before pregnancy
Preeclampsia
Preeclampsia: gestational hypertension with proteinuria, renal insufficiency, thrombocytopenia, evidence of liver damage (e.g., elevated liver enzymes, epigastric pain),
Preeclampsia without severe features - Usually asymptomatic - Nonspecific symptoms may include: - Headaches - Visual disturbances - RUQ or epigastric pain - Rapid development of edema - Hypertension - Proteinuria Preeclampsia with severe features - Severe hypertension (systolic ≥ 160 mmHg or diastolic BP ≥ 110 mmHg) - Proteinuria, oliguria - Headache - Visual disturbances (e.g., blurred vision) - RUQ or epigastric pain - Pulmonary edema - altered mental state
Superimposed preeclampsia
Superimposed preeclampsia: preeclampsia that occurs in a patient with chronic hypertension
HELLP syndrome
HELLP syndrome: a life-threatening form of preeclampsia (HELLP is an acronym: H = hemolysis; EL = elevated liver enzymes; LP = low platelets)
CF
Onset: most commonly > 27 weeks gestation (30% occur postpartum)
Preeclampsia
Nonspecific symptoms: nausea, vomiting, diarrhea
RUQ pain (liver capsule pain; liver hematoma)
Rapid clinical deterioration (DIC, pulmonary edema, acute renal failure, stroke, abruptio placentae)
Eclampsia
Eclampsia: severe form of preeclampsia with convulsive seizures and/or coma
Onset: the majority of cases occur in the intrapartum and postpartum period
Eclamptic seizures: generalized tonic-clonic seizures
Deterioration with headaches, RUQ pain, hyperr
Risk factors
General risk factors - Thrombophilia (e.g., antiphospholipid syndrome) - Age < 20 or > 40 years - African-American race - Diabetes mellitus or gestational diabetes - Chronic hypertension - Chronic renal disease (e.g., SLE) Pregnancy-related risk factors - Nulliparity - Previous preeclampsia - Multiple gestation (twins) - Hydatidiform moles
pathophysiology
Overview: Multiple maternal, fetal, and placental factors are involved in placental hypoperfusion, which leads to maternal hypertension and other consequences.
Arterial hypertension with systemic vasoconstriction causes placental hypoperfusion → release of vasoactive substances → ↑ maternal blood pressure to ensure sufficient blood supply of the fetus
Systemic endothelial dysfunction causes placental hypoperfusion → ↑ placental release of factors → endothelial lesions that lead to microthrombosis;
Consequences of vasoconstriction and microthrombosis
- Chronic hypoperfusion of the placenta → insufficiency of the uteroplacental unit and fetal growth restriction
prenatal screening
Prenatal screening for hypertensive pregnancy disorders
Maternal blood pressure
Maternal weight
Maternal urine status (urine dipstick)
Initial workup
To diagnose PIH, blood pressure must be elevated on at least 2 occasions that are at least 4 hours apart
Hypertension ≥ 140/90 mmHg
Severe hypertension: systolic BP ≥ 160 mmHg or diastolic BP ≥ 110 mmHg
Urine tests to determine proteinuria
24-hour urine collection (gold standard): ≥ 300 mg/24 h
Urine dipstick: 1–2 + protein
Laboratory analysis
CBC
Kidney function tests
Peripheral smear (assess for hemolysis) and coagulation studies are indicated if HELLP syndrome is suspected (i.e., thrombocytopenia and/or liver function impairment are present)
treatment of Gestational hypertension and Preeclampsia without severe features
Initial antepartum evaluation: assess maternal and fetal status and necessity for hospitalization and delivery
Fetal ultrasound (estimate fetal weight and amniotic fluid volume)
Non-stress test (NST)
Biophysical profiling if NST is nonreactive
Hospitalization and delivery indicated if:
- Pregnancy ≥ 37 0/7 weeks gestation
- Suspected placental abruption
- Pregnancy ≥ 34 0/7 weeks gestation plus one of the following
- Labor or rupture of membranes
- Fetal weight < 5th percentile
- Oligohydramnios
- Abnormal maternal or fetal test results
In all other cases, continue outpatient monitoring
Maternal monitoring: (1–2 x/week)
Fetal monitoring: ultrasound every 3 weeks
Antihypertensive drug therapy for severe hypertension (systolic BP ≥ 160 mmHg or diastolic BP ≥ 110 mmHg)
First-line agents
- Labetalol
- Hydralazine
- Nifedipine
treatment of Preeclampsia with severe features
Delivery (only curative option!) is indicated if:
Pregnancy is ≥ 34 0/7 weeks gestation
Pregnancy is < 34 0/7 weeks gestation with maternal or fetal instability
Immediate delivery after stabilization (IV magnesium sulfate prophylaxis, antihypertensive drugs, corticosteroids ) if Pulmonary edema is present
Procedure: vaginal delivery should be conducted if possible, but often cesarean delivery is needed for younger gestational age, immature cervix, or poor maternal or fetal condition
Expectant management: if pregnancy < 34 weeks and mother and fetus are stable
Monitor in facilities with maternal and neonatal ICU
Daily maternal monitoring
Daily fetal non-stress test and kick count; twice weekly BPP; ultrasound every two weeks
Oral antihypertensive treatment of severe hypertension
Magnesium sulfate for prophylaxis of eclampsia
Administer corticosteroids for fetal lung maturity
pulmonary edema
treatment of Eclampsia
Stabilization
Anticonvulsive therapy
- Magnesium sulfate IV (first-line)
- Antidote: calcium gluconate IV if early signs of magnesium toxicity (decreased deep tendon reflexes)
Position patient on left lateral decubitus position → prevent placental hypoperfusion through compression of the inferior vena cava
Delivery: once the mother is stable and seizures have stopped
treatment of HELLP syndrome
Stabilization
Blood transfusions
Antihypertensive agents (labetalol, hydralazine)
Magnesium sulfate
Delivery: if ≥ 34 weeks gestation or at any gestational age with deteriorating maternal or fetal status
complications and prevention
Maternal complications Placental abruption Cerebral hemorrhage, stroke DIC Acute respiratory distress syndrome (ARDS) Maternal death Fetal complications Fetal growth restriction Preterm birth Seizure-induced fetal hypoxia Fetal death
prevention: Prophylactic low-dose ASA PO from 12–14 weeks gestation for patients with a high risk of developing preeclampsia
