Ectopic Pregnancy
- embryo implants outside of the endometrial cavity (uterus)
- 1/100 pregnancies
- commonest locations: Ampullary (70%) >> isthmal (12%) > fimbrial (11%) > ovarian (3%) > interstitial (2%) > abdominal (1%)
- fourth leading cause of maternal mortality, leading cause of death in first trimester
Etiology
- 50% due to damage of fallopian tube cilia following PID
- intrinsic abnormality of the fertilized ovum
- transmigration of fertilized ovum to contralateral tube
Risk Factors
- previous ectopic pregnancy (strongest risk factor)
- smoking
- infertility treatment (IVF pregnancies following ovulation induction [7% ectopic rate])
- gynecologic: current IUD use, history of PID (especially infection with C. trachomatis), salpingitis and infertility
- previous procedures: any surgery on fallopian tube (for previous ectopic, tubal ligation), abdominal surgery for ruptured appendix
- structural: uterine leiomyomas, adhesions, abnormal uterine anatomy (e.g. T-shaped uterus)
- More than half of patients with ectopic pregnancy have no risk factors
Diagnosis
Clinical Features
- 4Ts and 1S:
Temperature >38°C (20%)
Tenderness: abdominal (90%) ± rebound (45%)
Tenderness on bimanual examination, cervical motion tenderness
Tissue: palpable adnexal mass (50%) (half have contralateral mass due to lutein cyst)
Signs of pregnancy (e.g. Chadwick’s sign, Hegar’s sign)
Investigations
- β-hCG levels
normal doubling time with intrauterine pregnancy is 1.6-2.4 d in early pregnancy
85% of ectopic pregnancies demonstrate abnormal β-hCG doubling
does not provide information on location of implantation
- ultrasound:
only definitive if fetal cardiac activity is detected in the tube or uterus
finding on transvaginal U/S is a tubal ring
- suspect ectopic in case of empty uterus with β-hCG >5000 and no bleeding
- laparoscopy (sometimes used for definitive diagnosis)
DDx of Lower Abdominal Pain
- Urinary tract: UTI, kidney stones
- GI: diverticulitis, appendicitis
- Gyne: endometriosis, PID, fibroid
(degenerating, infarcted, torsion), ovarian torsion, ovarian neoplasm, ovarian cyst, pregnancy-related
Treatment
goals
- conservative (preserve tube if possible), maintain hemodynamic stability
surgical=laparoscopy
- linear salpingostomy (cutting a hole in FT) an option if tube salvageable
- salpingectomy (removal of the whole fallopian tube) if tube damaged or ectopic is ipsilateral recurrence
- Rh negative should receive anti-D Rh immunoglobulin (RhoGAM) so that subsequent pregnancies will not be affected by hemolytic disease.
- may require laparotomy if patient is unstable
medical=methotrexate (immunosuppressive)
indications
<3.5 cm unruptured ectopic
AND no fetal heart rate
AND b-hCG <5,000
AND no hepatic/renal/ hematological disease
AND able and willing to follow-up
indications
- Vital signs unstable
- ->3.5 cm unruptured ectopic
OR fetal heart rate present
OR b-hCG >5,000
OR hepatic/renal/haematological disease
OR poor compliance OR unable to follow-up
- 50 mg/m2 body surface area; given in a single IM dose --> minimal side effects (reversible hepatic dysfunction,
diarrhea, gastritis, dermatitis) - follow β-hCG levels weekly until β-hCG is non-detectable
- 82-95% success rate, but up to 25% will require a second dose
Suspected Ectopic Pregnancy
- Positive urine -hCG
- Unilateral lower abdominal or pelvic pain
- Vaginal bleeding
If Ectopic Pregnancy Ruptures
• Acute abdomen with increasing pain
• Abdominal distention
• Shock (hypotensive)
- we should monitor:
-CBC to monitor for anemia
-Blood type/screen
-Transaminases to detect changes indicating hepatotoxicity from the medications - Beta-HCG to assess for success of treatment via a decrease in beta-HCG until reaches zero