OB/GYN Cram Session

Overview

• This session is a rapid review for OB/GYN essentials, targeting Step 2 CK or shelf exams.
• Focus is on must-know points in obstetrics and gynecology.

Obstetrics

Postpartum Hemorrhage

• Defined as over 500mL blood loss in vaginal delivery or 1L in C-section.
• Common Causes:
  • Uterine Atony:
    • Uterus fails to contract post-delivery -> spiral arteries hemorrhage.
    • Uterus above umbilicus indicates weak, boggy uterus.
    • Treatment:
      • Uterine massage.
      • Administer oxytocin if needed.
  • Retained Placenta:
    • Uneven endometrial lining on ultrasound.
    • Treatment:
      • D&C to remove retained tissue.
  • Lacerations:
    • Often with forceps delivery.
    • Treatment:
      • Pelvic exam and suture lacerations.

Labor and Delivery

• Active Phase: 6 to 10 cm dilation.
  • Arrest of Active Phase:
    • 4 hours of adequate contractions or 6 hours of inadequate contractions.
  • Adequate Contractions:
    • Every 2-3 minutes or >200 Montevideo units in 10 minutes.
  • Arrest of Descent:
    • Failure to deliver after full cervical dilation (3 hours).
    • Commonly due to cephalopelvic disproportion.
    • Treatment:
      • Typically requires C-section.

Other Conditions

• Uterine Rupture:
  • Presents with sudden intense pain, fetal station regression.
  • Immediate C-section and laparotomy needed.
• Prolapsed Cord:
  • Umbilical cord descends before fetus.
  • Requires C-section.

Fetal Heart Rate

• Normal Range: 110-160 bpm.
• Fetal Tachycardia:
  • Often due to maternal fever.
  • Causes: Pyelonephritis, chorioamnionitis.
• Tachysystole:
  • More than 5 contractions in 10 minutes.
  • Treat with tocolytic (e.g., terbutaline).

Pregnancy Changes

• Cardiac Output and GFR Increase.
• Metabolic Alkalosis:
  • Due to increased respiratory demand.

Shoulder Dystocia

• First Action: McRoberts Maneuver (hip hyperflexion).
• Risk Factors: Prior dystocia, macrosomia, gestational diabetes.
• Complications: Erb's palsy, clavicular fracture.

Infections

• Endometritis:
  • Postpartum uterine infection, treated with clindamycin and gentamicin.
• Chorioamnionitis:
  • Infection after prolonged membrane rupture.
  • Treated with ampicillin and gentamicin.

Genetic Conditions and Screening

• Nuchal Translucency: Indicates Down syndrome or trisomy 18.
• Elevated AFP: Suggests neural tube defect or abdominal wall defect.

Pregnancy Complications

• Placental Abruption: Painful third-trimester bleeding.
• Placenta Previa: Painless bleeding.
• Placenta Accreta Spectrum (PAS): Ranges from accreta to percreta.

Complications of Multiple Gestations

• Higher risk of preterm birth, malformations, preeclampsia.

Drugs During Pregnancy

• Preterm Labor Management:
  • Magnesium: Neuroprotection (up to 32 weeks).
  • Tocolytics: Delay labor (up to 34 weeks).
  • Betamethasone: Fetal lung maturity (up to 37 weeks).

Neonatal Infections

• Common Infections: Group B Strep, E. coli, Listeria.
• Preterm PROM: Risk of oligohydramnios and cord compression.

Genetic and Infectious Considerations

• Parvovirus: Causes fetal anemia.
• CMV: Characterized by chorioretinitis, microcephaly, calcifications.
• Toxoplasmosis: From cat litter, causes calcifications, hydrocephalus.

Routine Prenatal Care

• Initial Visit: Blood type, CBC, prenatal screening.
• Week 28: Test for gestational diabetes, administer Rhogam if needed.
• Week 35-37: Group B Strep culture.

Breastfeeding

• Preferred for first 6 months. Supplements needed for vitamin D and K.

Postpartum Conditions

• Thyroiditis: Hyper- and hypothyroid phases post-delivery.

Conclusion

• This session provides a comprehensive review of essential OB/GYN concepts.
• Ensure understanding of common conditions and management approaches in obstetrics, preparing for exams effectively.