Ectopic Pregnancy

Snapshot

A 24-year-old woman presents to the ED with 6 hours of severe left lower quadrant abdominal pain and some moderate vaginal bleeding. She is sexually active with 1 male partner and uses condoms occasionally. She has a history of pelvic inflammatory disease. Her last period was 7 weeks ago. A transvaginal ultrasound is performed and shows a mass in the left adnexa.

Introduction

Overview
- ectopic pregnancy is any pregnancy outside the uterine cavity
- ruptured ectopic is when the structure containing the pregnancy (such as fallopian tube) ruptures
- second leading cause of maternal mortality
Epidemiology
- incidence
  - 6-16% among women who present to ED with vaginal bleeding and/or pain
  - estimated overall incidence 0.28-2.1% of pregnancies in U.S.
- location
  - most commonly found in the fallopian tubes (96%)
    - ampulla (75%)
    - isthmus (12%)
  - other sites
    - abdomen
    - hysterotomy scar (embedded in cesarean scar)
    - cervix
- risk factors
  - prior ectopic pregnancy
  - pelvic inflammatory disease (PID)
  - intrauterine device (IUD) use
    - low risk of any pregnancy, but if pregnancy occurs then higher risk of ectopic than women not using IUD
  - prior tubal surgery
  - advanced maternal age
Pathogenesis
- implantation of fertilized egg outside of the uterine cavity
Prognosis
- life-threatening, if ruptured
pregnancy is non-viable

Presentation

History
- woman of reproductive age
- patient is sexually active
- missed recent period
Symptoms
- usually present in first trimester
  - 6-8 weeks after last normal menstrual period
- abdominal/pelvic pain
  - may be sudden onset or slow onset
  - no one typical type of pain: may be constant/intermittent, sharp/dull, and mild – severe
  - referred shoulder pain may be present if rupture with sufficient blood to irritate diaphragm
- vaginal bleeding or spotting
- amenorrhea
- other symptoms of pregnancy
  - breast tenderness
  - frequent urination
  - nausea
- temperature > 38°C is unusual (look for infectious cause)
- may be asymptomatic
Physical exam
- cervical motion tenderness
- adnexal mass
- blood in vaginal canal
- ruptured ectopic pregnancy may present with
  - hypotension
  - signs of shock
acute abdomen

Imaging

Transvaginal ultrasound
indications
- elevated β-hCG with no signs of uterine gestational sac on ultrasound is highly suspicious for ectopic
- assess for site of gestational sac with a yolk sac or embryo
- measuring the size will guide treatment
findings
- peritoneal free fluid if ruptured
- if no mass visualized inside or outside uterus
  - rely on serum β-hCG quantification (≥ 1500 mIU/mL or failure to double after 48 hours) to determine if ectopic
“snowstorm” appearance of uterus indicates molar pregnancy

Studies

Differential

Ruptured ovarian cyst
- negative β-hCG (unless ruptures during pregnancy)
- vaginal bleeding not usually associated
- pelvic ultrasound
  - may see thin wall of previous cyst
  - may see free fluid (also in ruptured ectopic)
Molar pregnancy
- will see “snowstorm” appearance of uterus on ultrasound
- β-hCG may be much higher than in typical pregnancy or ectopic
Spontaneous abortion
- intra-uterine pregnancy may be visualized on ultrasound
- cervical os may be open on pelvic exam
- may have passage of fetal contents from vagina
β-hCG will decrease on 48-hour repeat test

Treatment

Medical
- methotrexate
  - contraindicated if patient currently breastfeeding
- must meet the following criteria
  - β-hCG ≤ 5000 mIU/mL
  - gestational sac < 3.5 cm
  - no fetal heart tone
- RhoGAM (anti-D immune globulin)
  - give to all Rh(D)-negative mothers to prevent antibody formation
Surgical
- laparoscopic salpingostomy
  - if does not meet criteria for medical management
  - no signs of rupture
- laparoscopic salpingectomy
  - if evidence of rupture
    - free fluid in pelvic cavity
    - signs of shock
Follow up post-treatment β-hCG levels to ensure complete destruction of trophoblastic tissue

Complications

Recurrent ectopic pregnancy
- incidence
  - approximately 15%
- due to anatomic and functional changes in fallopian tubes secondary to clinical or subclinical salpignitis
Infertility
- incidence
  - 11-62%
- risk factors
  - prior history infertility
    - pregnancy rate following ectopic pregnancy in women with history of infertility is one-fourth that of women without known infertility prior to ectopic
  - decreased risk if ectopic occured during IUD use
Death
- incidence
  - approximately 31.9 per 100,000 pregnancies
- risk factors
  - ruptured ectopic pregnancy
    - severe hemorrhage from intraperitoneal bleeding