Pregnancy

Question 1

Physiologic Changes in Pregnancy

Cardiovascular

Answer 1

↑ Cardiac output (by 30–50%): due to ↑ stroke volume and ↑ heart rate
• ↓ Systemic vascular resistance → ↓ BP in 2nd trimester
• ↑ Blood volume (plasma > RBCs) → physiologic anemia
• Venous stasis → ↑ risk of DVT and varicose veins

Tip: Dyspnea and mild tachycardia are normal in pregnancy; persistent high BP or proteinuria is not.

Question 2

Physiologic Changes in Pregnancy

Respiratory

Answer 2

↑ Tidal volume and minute ventilation (↑ progesterone stimulates respiratory center)
• ↓ PaCO₂ (chronic respiratory alkalosis)
• ↑ O₂ delivery to fetus via maternal hypocapnia and right-shifted fetal Hb-O₂ curve

Tip: Mild respiratory alkalosis is normal; compensatory renal bicarbonate loss may cause a slightly decreased serum HCO₃⁻.

Question 3

Physiologic Changes in Pregnancy

Renal

Answer 3

↑ GFR → ↓ serum BUN and creatinine
• ↑ Renal plasma flow
• Mild glucosuria and proteinuria can be normal

Tip: Creatinine of 1.0 is not normal in pregnancy—it should be lower (e.g., ~0.4–0.6 mg/dL).

Question 4

Physiologic Changes in Pregnancy

GI

Answer 4

↓ Motility → constipation, reflux (↓ LES tone from progesterone)
• ↑ Cholesterol saturation of bile → ↑ risk of gallstones

Tip: Progesterone relaxes smooth muscle → GI symptoms + urinary stasis.

Question 5

Ectopic pregnancy

Answer 5

Implantation outside the uterus, most commonly in the ampulla of the fallopian tube
• Presentation: Abdominal pain, vaginal bleeding, positive β-hCG, no intrauterine pregnancy on ultrasound

Risk factors: PID (Chlamydia), previous ectopic, tubal surgery

Tip: Always consider ectopic in 1st-trimester pain + positive β-hCG + no IUP.

Question 6

Preeclampsia

Answer 6

New-onset hypertension after 20 weeks + proteinuria or signs of end-organ damage
• Pathophysiology: Abnormal placentation → endothelial dysfunction, vasoconstriction, ischemia
• Complications:
• Eclampsia: seizures
• HELLP syndrome: Hemolysis, Elevated Liver enzymes, Low Platelets

Tip: Severe preeclampsia: BP ≥160/110, visual symptoms, pulmonary edema, elevated creatinine or LFTs

Question 7

Gestational Diabetes Mellitus (GDM)

Answer 7

Insulin resistance due to placental hormones (e.g., human placental lactogen)
• Screen at 24–28 weeks with oral glucose challenge
• Risks: Macrosomia, shoulder dystocia, neonatal hypoglycemia

Tip: Most revert postpartum, but ↑ risk of T2DM later. Know the effects on the fetus: macrosomia, hypoglycemia, RDS.

Question 8

Placental abruption

Answer 8

Premature separation of placenta from uterus
• Painful bleeding, uterine tenderness, fetal distress
• Associated with trauma, hypertension, cocaine use

Tip: Sudden painful third-trimester bleeding = think abruption.

Question 9

Placenta Previa

Answer 9

Placenta covers cervical os
• Painless third-trimester bleeding
• Diagnosed via ultrasound, not digital exam

Tip: Painless bleeding late in pregnancy = placenta previa; painful = abruption.

Question 10

Vasa previa

Answer 10

Fetal vessels run over os and rupture during membrane rupture
• Triad: Membrane rupture, painless vaginal bleeding, fetal bradycardia

Tip: Always suspect in sudden fetal distress after membrane rupture.

Question 11

Hydatidiform Mole (Molar Pregnancy)

Answer 11

Complete mole: 46,XX or XY, no fetal parts, massively ↑ β-hCG, “snowstorm” on ultrasound
• Partial mole: 69,XXX/XXY, fetal parts present

Tip: Uterine size > dates, hyperemesis gravidarum, very high β-hCG. Know risk of progression to choriocarcinoma.

Question 12

Choriocarcinoma

Answer 12

Malignant trophoblastic tumor; can follow molar pregnancy, abortion, or normal pregnancy
• ↑ β-hCG, early hematogenous spread to lungs

Tip: Hemoptysis or respiratory symptoms post-pregnancy event + ↑ β-hCG = suspect choriocarcinoma