Contents
Implantation of a fertilized oocyte outside the uterine cavity.
- Tubal ectopic (M/C): Ampulla (70%) > Isthmus (12%) > Infundibulum (11%) > Interstitial & cornual (least common, 2-3%)
- M/C non-tubal site: Ovary
- Least common site: Cervical ectopic/ectopic in cesarean scar

Etiology
Extrauterine pregnancy is of multifactorial origin. Up to half of all women with an extrauterine pregnancy have no recognized risk factors for it.
- Prior tubal surgery (biggest risk factor)
- Prior ectopic pregnancy
- History of infertility
- PID (M/C cause): Salpingitis >> oophoritis, endometritis
- M/C organism: Chlamydia
- Ruptured appendix
- Smoking
- Contraceptive methods: IUDs, PIPs, tubal sterilization
- Salpingitis isthmica nodosa (SIN): Inflammatory condition of the fallopian tubes strongly associated with infertility and an increased risk of ectopic pregnancy

Presentation
Most commonly diagnosed in the 6th through 9th week of gestation. and commonly present with pain and vaginal bleeding between 6 and 10 weeks’ gestation.

Intact tubal pregnancy:
Intact fallopian tube and embryo, perhaps with discernible cardiac function
- Usually asymptomatic
Classical triad: 30% cases
May indicate extrauterine pregnancy but can also arise in an intact intrauterine pregnancy or as a consequence of early miscarriage
- Aching pelvic pain
- Mild vaginal spotting
- Secondary amenorrhea
Other features:
- Endometrial sloughing: Endometrial growth not maintained d/t fall in β-hCG & progesterone
- Decidual cast: Entire decidua expelled at once
Ruptured ectopic pregnancy:
Pelvic pain with severe hemorrhagic shock
- Hemorrhagic shock/hemodynamic instability (dyspnea, hypotension, tachycardia)
- Syncope
- Danforth sign: Shoulder pain on inspiration, due to irritation of the diaphragm by a hemoperitoneum in ruptured ectopic pregnancy
- Abdominal guarding or an acute abdomen
Diagnosis
40% of ectopic pregnancies go undiagnosed on initial presentation.
Diagnostic criteria:
- Paalman & McElin criteria (cervical ectopic clinical criteria)
- Rubin criteria (cervical ectopic histological criteria)
- Studdiford criteria (abdominal ectopic)
- Spiegelberg criteria (ovarian ectopic)
Transvaginal ultrasonography (TVS):
Investigation of choice
- Empty uterus (1st sign on USG)
- Tubal ring sign or bagel/blob sign: Echogenic ring surrounding an unruptured ectopic pregnancy
- Pseudogestational sac: Small fluid collection, centrally located within endometrial cavity and surrounded by thick decidual reaction
- Complex adnexal mass



Serum β-Human chorionic gonadotrophin (β-hCG):
Performed if TVS inconclusive
- Critical titre (levels at which gestational sac should be visible on USG):
- TVS: 1500 IU/l
- TAS: 6500 IU/l
- Repeat test done after 48hr if β-HCG < 1500 IU/l:
- β-HCG ↑ (x2): Normal pregnancy
- β-HCG ↓ : Abortion
- β-HCG ↑ (< x2): Ectopic pregnancy

Culdocentesis:
Procedure to obtain free fluid from the cul de sac of women indicated in suspected ruptured ectopic pregnancy and acute salpingitis or pelvic inflammatory disease (PID).
- Non-clotting blood: Hemoperitoneum (suspect ectopic pregnancy)
- Clotting blood: Vein/artery aspirated (remove needle, re-insert to aspirate again)

Differential diagnosis:
- Appendicitis (M/C mistaken for)
- Cystic/solid adnexal tumors causing peritoneal irritation (esp by torsion or rupture)
- Adnexal infection (e.g., PID, UTI, tubo-ovarian abscess)
- Ovarian hyperstimulation syndrome with ascites
Management
Expectant management:
Some ectopic pregnancies resolve spontaneously, and expectant management is possible in selected cases.
- Not preferred
Medical management:
Treatment of choice before rupture in haemodynamically stable patients with hCG <5000 IU/l, rising hCG level within 48 hours and a gestational sac <4 cm
- DOC: Methotrexate (folic acid antagonist) (IM/direct local injection)
- Close follow up with serial measurements of serum concentrations of hCG required. 3 courses can be attempted before surgical intervention.
- Other drugs: Potassium chloride, actinomycin, hyperosmolar glucose, PGF2-α
Surgical management:
Indicated in rupture, hemodynamic instability, symptoms (eg., pain), diagnostic laparoscopy or suspected heterotopic pregnancy
- Radical procedure (salpingectomy)
- Conservative procedure (salpingostomy)
- Anti-D (300 µg): Alloimmunization after surgical management of ectopic pregancy

