Author:
IvetteMotola
PatriciaDe Melo Panakos
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:
- Multiple previous elective abortions
- Previous early pregnancy loss
- Toxins
Signs and Symptoms
History
- 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
Physical Exam
- 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 & Interpretation
Lab
- 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
Imaging
- 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
Prehospital
- 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:
- 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
First Line
- 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
Second Line
Usually given in consultation with OB/GYN:
- 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
Admission Criteria
- Suspected unstable ectopic pregnancy (see “Ectopic Pregnancy”)
- Hemodynamically unstable patients with hypovolemia or anemia
- DIC
- Septic abortions
- Suspected gestational trophoblastic disease
Discharge Criteria
- 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
- Committee on Practice Bulletins—Gynecology. The American College of Obstetricians and Gynecologists Practice Bulletin no. 150. Early pregnancy loss . Obstet Gynecol. 2015;125:1258-1267.
- DoubiletPM, BensonCB, BourneT, et al. Diagnostic criteria for nonviable pregnancy early in the first trimester . N Engl J Med. 2013;369:1443-1451.
- HuancahuariN. Emergencies in early pregnancy . Emerg Med Clin North Am. 2012;30:837-847.
- MazzariolFS, RobertsJ, OhSK, et al. Pearls and pitfalls in first-trimester obstetric sonography . Clin Imaging. 2015;39:176-185.
- SapraKJ, JosephKS, GaleaS, et al. Signs and symptoms of early pregnancy loss . Reprod Sci. 2017;24:502-513.
- TintinalliJ, StapczynkiJS, MaOJ, et al. Tintinalli's Emergency Medicine: A Comprehensive Study Guide, 8th ed.New York: McGraw-Hill Education, 2016.
See Also (Topic, Algorithm, Electronic Media Element)