Description

• Spontaneous termination of a <20 wk intrauterine pregnancy
• Synonyms: Early pregnancy loss, miscarriage, early pregnancy failure
• Occurs in up to 10–15% of recognized pregnancies (most common complication of early pregnancy):
  • ∼80% occur in first trimester
• Vaginal bleeding in the first trimester is seen in about 25% of pregnant patients:
• Definitions:
  • Threatened abortion: Vaginal bleeding, cervical os is closed, viable intrauterine pregnancy confirmed:
    • 50% of women seen in the ED for threatened abortion will eventually miscarry
  • Inevitable abortion: Vaginal bleeding, cervical os is open; products of conception (POC) have not been expelled
  • Incomplete abortion: Vaginal bleeding, cervical os is open with partial passage of some POC and some retained POC
  • Complete abortion: Vaginal bleeding, cervical os closed, complete passage of POC; no surgical or medical intervention
  • Missed abortion: Fetal demise with no uterine activity to expel
  • Septic abortion: Spontaneous abortion complicated by intrauterine infection
  • Recurrent spontaneous abortion: 3 or more consecutive pregnancy losses

Etiology

• Chromosomal abnormalities of the fetus
• Uterine abnormalities (e.g., leiomyoma, uterine adhesions, congenital anomalies)
• Risk factors include:
  • Increased age of both mother and father
  • Increased parity
  • Alcohol use
  • Cigarette smoking
  • Cocaine use
  • Conception within 3–6 mo after delivery
  • Chronic maternal disease:
    • Poorly controlled diabetes
    • Autoimmune disease
    • Celiac disease
  • Intrauterine device
  • Maternal BMI <18 or >25 kg/m²
  • Maternal infections:
    • Bacterial vaginosis
    • Mycoplasmosis
    • Herpes simplex
    • Toxoplasmosis
    • Listeriosis
    • Chlamydia/gonorrhea
    • HIV
    • Syphilis
    • Parvovirus B19
    • Malaria
    • CMV
    • Rubella
  • Medications:
    • Misoprostol
    • Methotrexate
    • NSAIDs
  • Multiple previous elective abortions
  • Previous early pregnancy loss
  • Toxins

Signs and Symptoms

• Last menstrual period (LMP)
• Obstetric history:
  • Parity
  • Risk factors for pregnancy loss
  • Prenatal care
• Abdominal pain, cramping
• Vaginal bleeding:
  • Duration
  • Amount of bleeding (quantify by number of pads used, compare with normal menstrual period for patient)
  • Passage of clots
• Dizziness, syncope

• Determine hemodynamic status of patient:
  • Pregnant patients in late first trimester have an increased blood volume:
    • Can lose substantial amount of blood before having abnormal vital signs
• Pelvic exam:
  • Determine whether the internal cervical os is open or closed
  • Amount of bleeding
  • Presence of POC
  • Presence of adnexal tenderness or peritoneal irritation can be consistent with an ectopic pregnancy
• Bimanual exam to determine the size of the uterus:
  • Size of an orange: 6–8 wk
  • Fundus at the symphysis pubis: 12 wk
  • Fundus at the umbilicus: 16–20 wk

Essential Workup

• Pregnancy test as below
• Imaging as below

Diagnostic Tests and Interpretation

• Confirm pregnancy with a urine or serum test:
  • Urine pregnancy test: Most are positive at β-hCG levels of 25–50 mIU/mL ∼1 wk gestational age and remain positive 2–3 wk after induced or spontaneous abortions
• CBC
• Type and Rh
• Type and cross-match for woman with low Hct or signs of active blood loss
• Quantitative β-hCG
• Any POC passed should be sent to pathology for confirmation

• Transvaginal ultrasound (TVS):
  • Gestational sac seen at 4 wk
  • Cardiac activity seen at 5.5 wk
• Transabdominal ultrasound (TAS):
  • Gestational sac at 6 wk
  • Cardiac activity seen at 8 wk
• Discriminatory zone: Level of β-hCG where a normal IUP should be detected:
  • 1,500–2,000 for TVS
  • 6,500 for TAS
• Ultrasound findings consistent with early pregnancy loss:
  • Fetal crown–rump length of ≥7 mm and absent cardiac activity
  • Mean sac diameter of ≥25 mm without an embryo
  • Absence of an embryo with a cardiac activity ≥2 wk after a scan that showed a gestational sac without a yolk sac
  • Absence of an embryo with a cardiac activity ≥11 d after a scan that showed a gestational sac with a yolk sac

Differential Diagnosis

• Positive pregnancy test with vaginal bleeding:
  • Cervicitis
  • Ectopic pregnancy
  • Molar pregnancy
  • Pregnancy of unknown location (PUL)
  • Septic abortions
  • Subchorionic hemorrhage
  • Trauma
• Second- and third-trimester vaginal bleeding:
  • Placenta previa
  • Placental abruption

Pre Hospital

• IV fluids, oxygen, and cardiac monitor
• Monitor vital signs and transport
• Caution:
  • Patients with spontaneous abortion/vaginal bleeding can have severe hemorrhage and present in shock, especially at >12 wk
  • BP drops during the second trimester of pregnancy with an average of 110/70

Initial Stabilization/Therapy

• Stable patients:
  • IV
  • Pelvic exam
• Unstable patients:
  • Oxygen, IV fluids via 2 large-bore IVs, cardiac monitor
  • Transfuse PRBC if patient does not stabilize after 2–3 L of crystalloid
  • Gynecologic consultation immediately
  • Oxytocin or methylergonovine may be necessary to control hemorrhage
  • These patients are at high risk for having ruptured ectopic pregnancies and may need emergent operative intervention

Ed Treatment/Procedures

• Threatened abortion:
  • Pelvic rest, close follow-up with obstetrics
  • Patients <6.5-wk pregnant with no documented cardiac activity by vaginal US need to be followed with serial β-hCG to assess the viability of the fetus and to rule out ectopic pregnancy
• Inevitable and incomplete abortions:
  • Expectant management:
    • Successful in up to 80%
    • Increased risk of unplanned surgical intervention and blood loss as compared to surgical management
  • Medical management:
    • Misoprostol
    • Successful in 80–93%
    • Reduces need for uterine curettage by up to 60%
    • Shortens time to completion
  • Surgical management:
    • Dilation and curettage (D&C) or evacuation, removal of POC at the cervical os to help decrease bleeding and cramping
    • Should be performed urgently in active hemorrhage, hemodynamic instability, or signs of infection
    • Reduces unplanned hospital admissions, curettages, and blood transfusions
    • Successful in 99%
    • The confirmation of POC by pathology rules out ectopic pregnancy
• Complete abortion:
  • May treat with methylergonovine or oxytocin if bleeding is heavy
  • If quantitative β-hCG is <1,000 and the US is negative, may follow up with obstetrics for serial β-hCG to confirm the levels are decreasing
• Missed abortion:
  • These patients are at risk for disseminated intravascular coagulation (DIC), especially if fetus is retained >4–6 wk
  • Obtain CBC, PT/PTT, fibrin-split products (FSP), and fibrinogen levels
  • These patients may be followed closely as outpatients if stable with an early, confirmed IUP and no evidence of DIC
  • Patients may choose to have a D&C at a later date or miscarry at home with medication or no intervention; this decision should be made in consultation with OB/GYN

Medication

• RHO immunoglobulin in Rh-negative women:
  • 50 mcg for women with threatened or complete abortion at <12 wk
  • 300 mcg for women with threatened or complete abortion at ≥12 wk
• Patients need RhoGAM administration within 72 hr to prevent future isoimmunization
• Misoprostol 800 mcg vaginally if medical management is chosen in consultation with OB/GYN
  • Repeat dose in 48 hr as needed

• Oxytocin: 20 units in 1,000 mL of NS at a rate of 20 milliunits/min titrated to decrease bleeding; may repeat for a max dose of 40 milliunits/min
• Methylergonovine: 0.2 mg IM/PO QID for bleeding

Disposition

• Suspected unstable ectopic pregnancy (see “Ectopic Pregnancy”)
• Hemodynamically unstable patients with hypovolemia or anemia
• DIC
• Septic abortions
• Suspected gestational trophoblastic disease

• D&Cs/Evacuations can be done in the ED for incomplete and inevitable abortions, and patients may be discharged home if stable after 2–3 hr
• Some early inevitable miscarriages can be discharged to complete their miscarriages at home without a D&C/Evacuation
• Discharge with pain medications and close OB/GYN follow-up
• Patients with threatened abortions should be told to avoid strenuous activity
• Pelvic rest (i.e., “nothing in the vagina” during active bleeding; due to increased risk of infection)
• Patients should be instructed to return to the ED for any increase in bleeding, dizziness, or temperature >100.4°F
• Patients and their partners should be counseled that early pregnancy loss is common and that it is not anyone's fault

Follow-Up Recommendations

Patients with positive pregnancy tests and vaginal bleeding with or without abdominal pain should be followed by OB/GYN

See Also

• Ectopic Pregnancy
• Vaginal Bleeding