Module 6.0

Course Overview

  • Course Name: DMST 244 - Obstetrics & Gynecology I

  • Module: 6

  • Topic: 1st Trimester Abnormalities: Ectopic Pregnancies

Key Terms and Definitions

  • Pregnancy of Unknown Location (PUL): Situation where β-HCG is positive but ultrasound shows no intrauterine pregnancy (IUP).

  • Ectopic Pregnancy: Defined as a pregnancy that occurs outside the uterine canal/cavity.

Ultrasound Appearance in Ectopic Pregnancy

Key Diagnostic Measures

  • Mean Sac Diameter (MSD)
      - Used when embryo is not identified.
      - Ensure observation of the double decidual reaction.
      - Visible from 4-5 weeks of gestation.
      - Calculation: MSD=Length+Width+Height3MSD=\frac{Length+Width+Height}{3}{}{}

  • Crown Rump Length (CRL)
      - Best used between 6 and 13 weeks.
      - Most accurate measurement for predicting gestational age with a margin of error of +/- 3 days.
      - Measured from the tip of the head to the end of the rump, excluding the yolk sac.

Growth Indicators

  • Gestational Sac Growth Rate:
      - 1.1 mm/day.

  • Gestational Sac Size at Various Weeks:
      - 6 weeks: 1.5 cm
      - 7 weeks: 2 cm
      - 8 weeks: 3 cm

  • Endovaginal Scans:
      - MSD of 8 mm indicates yolk sac seen.
      - MSD of 16 mm indicates embryo seen.

  • Transabdominal Scans:
      - MSD of 20 mm indicates yolk sac seen.
      - MSD of 25 mm indicates embryo seen.

Clinical Presentation

  • Classical Clinical Triad Symptoms:
      1. Pain
      2. Bleeding
      3. Adnexal mass
      - 45% of patients will demonstrate these symptoms.
      - Other symptoms may include amenorrhea, adnexal tenderness, and cervical tenderness.

Timing of Presentation

  • Ectopic pregnancies typically present between 5 and 8 weeks of gestation.

  • Risk Factors for Ectopic Pregnancy:
      - Previous ectopic pregnancy
      - Gynecological surgeries (especially tubal)
      - Pelvic inflammatory disease (PID)
      - Endometriosis
      - Intrauterine contraceptive device (IUCD) usage
      - Congenital anomalies
      - Assisted reproductive technology / infertility
      - Increased maternal age

Ectopic Sites

  • Common Locations:
      - Fallopian tube (95% of cases)
        - Ampulla is the most common
      - Cervix
      - Ovary
      - Peritoneal cavity

  • Dangerous Locations:
      - Cervix and interstitial segments due to risk of hemorrhage.

Sonographic Features of Ectopic Pregnancy

Diagnostic Findings

  • Key Features:
      - Adnexal mass
      - Free fluid in the pouch of Douglas (Pouch of Douglas).
      - Morrison's pouch presence.
      - Absence of IUP or presence of a pseudo-sac.

  • A live ectopic pregnancy is confirmed with a visible ectopic gestational sac and fetal heartbeat.

Differential Diagnoses of Ectopic Pregnancy

  • Very early intrauterine pregnancy

  • Spontaneous abortion

  • Ectopic pregnancy

Laboratory Indicators

  • β-HCG Levels:
      - An ectopic pregnancy may exhibit lower or normal levels of β-HCG.
      - Normally, β-HCG levels should double every 2 days for a viable pregnancy but may not do so in ectopic cases.

  • Useful β-HCG Testing DDX for Ectopic Pregnancy:
      - Early gestation: Expected increase in β-HCG
      - Spontaneous abortion: Expected decrease in β-HCG
      - PID: β-HCG negative indicates non-pregnant state
      - Complex ovarian cyst: β-HCG negative
      - Endometriosis: β-HCG negative

Ultrasound Signs and Appearances

  • Key Ultrasound Signs:
      - Tubal ring
      - Ring of fire (increased vascularity around ectopic gestation)
      - Sliding sac sign (movement of gestational sac upon manipulation)

Treatment Modalities for Ectopic Pregnancy

Overview

  • Management Options:
      - Conservative management
      - Medical therapy
      - Surgical intervention

Conservative Management

  • Watchful waiting for stable patients with controlled pain.

  • Monitoring via serial β-HCG measurements for decrease.

Medical Therapy

  • Methotrexate Usage:
      - A cell growth inhibitor effective in certain ectopic pregnancy cases.
      - Administered systemically or directly into the ectopic site.
      - Monitor β-HCG levels post-treatment; treatment success is more likely if β-HCG levels are less than 5000 mIU/mL.

Surgical Approaches

  • Laparoscopy or Laparotomy:
      - Salpingostomy: Incision to remove ectopic and restore patency for future fertility.
      - Salpingectomy: Removal of damaged fallopian tube; recommended for severe cases or recurrent ectopic situations.

Acute Ectopic Treatment Considerations

  • Untreated ectopic pregnancies may lead to rupture and hypovolemic shock, necessitating immediate surgical intervention in severe cases.