OBGYN_Placental abnormalities, Eclampsia, Abortion Flashcards
What is the strongest predisposing factor for placenta previa?
Uterine scarring, most commonly secondary to Cesarean sections or uterine surgeries.
Other risk factors for placenta previa:
- Advanced maternal age
- Multiparity
- Smoking
- Multiple gestations
What is the first step in evaluating third-trimester painless vaginal bleeding?
Transabdominal ultrasound to evaluate placental position and rule out placenta previa.
Why is vaginal examination contraindicated in suspected placenta previa?
Vaginal examinations can worsen bleeding and cause complications due to disruption of placental vessels.
What defines chronic hypertension in pregnancy?
Systolic ≥140 mm Hg or diastolic ≥90 mm Hg diagnosed before conception or before 20 weeks of gestation.
What defines gestational hypertension?
New-onset hypertension (systolic ≥140 mm Hg or diastolic ≥90 mm Hg) after 20 weeks of gestation without proteinuria or signs of end-organ damage.
What defines preeclampsia?
New-onset hypertension after 20 weeks of gestation with proteinuria (≥300 mg/24 hours) or signs of end-organ damage.
What is the general pathophysiology of preeclampsia?
Preeclampsia results from abnormal development of the uteroplacental circulation, causing systemic vasoconstriction, ischemia of organs, and endothelial dysfunction.
What is the recommended prophylaxis for high-risk patients to prevent preeclampsia?
Low-dose aspirin starting at 12-28 weeks until delivery.
When is the onset of preeclampsia?
Generally 20 weeks
Can occur earlier.
What are the maternal complications of preeclampsia?
Seizures (eclampsia)
Disseminated intravascular coagulation (DIC)
Pulmonary edema
Intracerebral hemorrhage
What are the obstetric complications of preeclampsia?
Uteroplacental insufficiency
Placental abruption
Fetal growth restriction
Oligohydramnios
What defines eclampsia?
Preeclampsia with new-onset tonic-clonic seizures.
What are the highest risk factors for preeclampsia?
History of preeclampsia
Advanced maternal age (>40 years old)
Young maternal age (<20 years old)
Multiple gestation
Black race
Vascular disease
Chronic hypertension, diabetes, kidney disease, obesity, or autoimmune disease
What are the risk factors that make for a moderate risk for preeclampsia?
Nulliparity
Obesity
Advanced age
What are the diagnostic criteria for preeclampsia?
Systolic BP ≥140 mmHg or diastolic BP ≥90 mmHg
PLUS one of the following:
1) Proteinuria (≥300 mg/24 hours or ≥2+ on dipstick)
2) Evidence of end-organ damage
Elevated liver enzymes
Renal dysfunction
pulmonary edema
thrombocytopenia
CNS symptoms like headaches or visual changes
What is the gold standard for diagnosing proteinuria in preeclampsia?
24-hour urine collection for total protein.
Why is urinalysis not definitive for diagnosing preeclampsia?
Urinalysis has a high rate of false negatives due to the small urine sample size compared to daily total urine output.
What is the management of preeclampsia without severe features at term?
Deliver at ≥37 weeks
IV magnesium sulfate for seizure prophylaxis at time of delivery
Antihypertensives for BP control
What distinguishes preeclampsia with severe features?
Systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg
New end-organ damage, such as:
CNS: Severe headache, scotomata
Renal: Creatinine >1.1 mg/dL or 2x baseline
GI: Elevated AST/ALT >2x normal
Platelets <100,000/mm³
Pulmonary edema
What is the management of preeclampsia with severe features?
Delivery if ≥34 weeks
IV magnesium sulfate
Antihypertensives to control BP to <160/110
If <34 weeks: Administer glucocorticoids and consider delivery
What evaluations are required for new-onset hypertension at ≥20 weeks gestation?
- Serial blood pressure measurements
- Evaluate for clinical signs of end-organ damage
- Laboratory evaluations (urinalysis, creatinine, transaminases, platelet count)
- Fetal well-being assessment (e.g., nonstress test).
Why is outpatient bed rest not recommended for gestational hypertension or preeclampsia?
It increases the risk of venous thromboembolism without preventing progression to preeclampsia.
What antihypertensives are used to treat severe hypertension in preeclampsia?
IV labetalol, IV hydralazine, or oral nifedipine.
What is eclampsia?
Eclampsia is defined as generalized tonic-clonic seizures in a patient with underlying preeclampsia.
It can lead to complications such as abruption, DIC, or cardiac arrest.
What is the management of eclampsia?
Initial steps: Ensure airway protection and maintain oxygenation. Place the patient in the lateral decubitus position to prevent aspiration and improve venous return.
Seizure control: Administer IV magnesium sulfate for seizure prophylaxis and control.
If seizures persist, give additional magnesium sulfate or second-line agents (e.g., lorazepam or phenytoin).
Blood pressure control: Use IV labetalol, IV hydralazine, or oral nifedipine to maintain BP <160/110 mmHg.
Delivery: Expedite delivery once the mother is stabilized. Delivery is the definitive treatment, regardless of gestational age.
Post-delivery monitoring: Continue magnesium sulfate for 24 hours postpartum for seizure prophylaxis. Monitor for signs of magnesium toxicity (e.g., loss of reflexes, respiratory depression, magnesium toxicity management involves use of IV calcium gluconate).
When is magnesium sulfate indicated in hypertensive disorders of pregnancy?
For seizure prophylaxis in preeclampsia with severe features and for fetal neuroprotection before 32 weeks if imminent delivery is expected.
What is the therapeutic range for magnesium sulfate in eclampsia prophylaxis?
4-8 mEq/L.
At what magnesium levels do toxicities occur?
7-10 mEq/L: Loss of deep tendon reflexes
10-15 mEq/L: Respiratory paralysis, altered cardiac conduction
> 25 mEq/L: Cardiac arrest
What is the immediate treatment for magnesium toxicity?
IV calcium gluconate to stabilize cardiac membranes and reverse symptoms.
What is the most common method used for induced abortion before 13 weeks’ gestation?
Dilation and curettage (D&C)
Complications include endometritis (which may require outpatient antibiotic treatment) and retained products of conception (which may require repeat curettage).
What are the complications associated with dilation and curettage (D&C)?
Endometritis and retained products of conception
Endometritis may require outpatient antibiotic treatment. Retained products of conception may necessitate repeat curettage.
What are the medical abortion methods used within the first 63 days of amenorrhea?
Mifepristone and misoprostol
Mifepristone is a progesterone antagonist that blocks progesterone, leading to uterine contraction, while misoprostol is a prostaglandin E1 analog that further induces uterine contractions.
What is the rare complication of medical abortion with mifepristone and misoprostol?
Incomplete abortion
Incomplete abortion may require dilation and curettage (D&C) to complete the abortion process.
What serious infection is associated with medical abortion?
Clostridium sordellii sepsis
Clostridium sordellii sepsis is associated with rapid onset of shock, organ failure, and death, requiring immediate medical attention.
