OBGYN_2

Question 1

What is the strongest predisposing factor for placenta previa?

Answer 1

Uterine scarring, most commonly secondary to Cesarean sections or uterine surgeries.

Other risk factors for placenta previa:
- Advanced maternal age
- Multiparity
- Smoking
- Multiple gestations

Question 2

What is the first step in evaluating third-trimester painless vaginal bleeding?

Answer 2

Transabdominal ultrasound to evaluate placental position and rule out placenta previa.

Question 3

Why is vaginal examination contraindicated in suspected placenta previa?

Answer 3

Vaginal examinations can worsen bleeding and cause complications due to disruption of placental vessels.

Question 4

What is the general pathophysiology of preeclampsia?

Answer 4

Preeclampsia results from abnormal development of the uteroplacental circulation, causing systemic vasoconstriction, ischemia of organs, and endothelial dysfunction.

Question 5

When is the onset of preeclampsia?

Answer 5

Generally 20 weeks

Can occur earlier.

Question 6

What are the obstetric complications of preeclampsia?

Answer 6

Uteroplacental insufficiency
Placental abruption
Fetal growth restriction
Oligohydramnios

Question 7

What are the maternal complications of preeclampsia?

Answer 7

Seizures (eclampsia)
Disseminated intravascular coagulation (DIC)
Pulmonary edema
Intracerebral hemorrhage

Question 8

What are the high risk factors for preeclampsia?

Answer 8

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

Question 9

What are the moderate risk for preeclampsia?

Answer 9

Nulliparity
Obesity
Advanced age

Question 10

What is the recommended prophylaxis for high-risk patients to prevent preeclampsia?

Answer 10

Low-dose aspirin starting at 12-28 weeks until delivery.

Question 11

What are the diagnostic criteria for preeclampsia?

Answer 11

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

Question 12

What is the management of preeclampsia without severe features at term?

Answer 12

Deliver at ≥37 weeks
IV magnesium sulfate for seizure prophylaxis at time of delivery
Antihypertensives for BP control

Question 13

What distinguishes preeclampsia with severe features?

Answer 13

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

Question 14

What is the management of preeclampsia with severe features?

Answer 14

Delivery if ≥34 weeks
IV magnesium sulfate
Antihypertensives to control BP to <160/110

If <34 weeks: Administer glucocorticoids and consider delivery

Question 15

What antihypertensives are used to treat severe hypertension in preeclampsia?

Answer 15

IV labetalol, IV hydralazine, or oral nifedipine.

Question 16

What is eclampsia?

Answer 16

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.

Question 17

What is the management of eclampsia?

Answer 17

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).

Question 18

What is the therapeutic range for magnesium sulfate in eclampsia prophylaxis?

Answer 18

4-8 mEq/L.

Question 19

At what magnesium levels do toxicities occur?

Answer 19

7-10 mEq/L: Loss of deep tendon reflexes

10-15 mEq/L: Respiratory paralysis, altered cardiac conduction

> 25 mEq/L: Cardiac arrest

Question 20

What is the immediate treatment for magnesium toxicity?

Answer 20

IV calcium gluconate to stabilize cardiac membranes and reverse symptoms.