EPL, often referred to as miscarriage or spontaneous abortion, includes all non-viable intrauterine pregnancies in the first trimester. EPL is common, occurring among 10-20% of clinically recognized pregnancies (ACOG 2015, Prine 2011, Blohm 2008). Nearly half of all EPLs are the result of random genetic errors (with the most common risk factors being age >35 years old and prior early pregnancy loss) while other factors such as environmental or other exposures, socioeconomic, and immunologic factors are also implicated (Lens 2021, ACOG 2015, Prine 2011). In most cases it’s not possible to determine the cause of the pregnancy loss.

Patients with EPL often present with vaginal bleeding and/or abdominal cramping. A non-viable pregnancy can also be an incidental finding detected by routine US or absence of fetal heart tones on doppler in the absence of symptoms. EPL can be classified based on clinical exam and US findings as outlined in the table below.

Terminology Clinical definition Ultrasound findings
Anembryonic Gestation Growth of a gestational sac without an associated embryo or yolk sac. Formerly called “blighted ovum” Enlarged gestational sac without embryo (See criteria in Chapter 3)
Embryonic or Fetal Demise Loss of viability of a developing embryo or fetus Embryonic or fetal pole ≥7mm with no electronic cardiac activity (see criteria in Chapter 3)
Missed Abortion A non-viable intrauterine pregnancy, either anembryonic or an embryonic demise, often discovered by US. The patient may be asymptomatic or have a history of bleeding. The cervix is closed. Anembryonic gestation or embryonic demise (see above)
Threatened Abortion Uterine bleeding without passage of gestational tissue.The cervix is closed. The pregnancy is viable at time of presentation and prognosis remains uncertain. Findings appropriate for stage of pregnancy, may or may not show subchorionic hemorrhage
Inevitable Abortion Bleeding and/or uterine cramping. Cervix is dilated and passage of tissue is expected. Findings may be appropriate for stage of pregnancy, +/- electronic cardiac activity.
Incomplete Abortion The cervix is dilated and some, but not all, of the pregnancy tissue is expelled. Heterogeneous or echogenic material, usually in the lower uterine cavity or in cervical canal
Complete Abortion The pregnancy tissue has expelled completely No pregnancy (sac/embryo or fetus) in intrauterine cavity, with possible endometrial thickening

Adapted from Prine 2011.

Avoid terminology such as “pregnancy failure,” “spontaneous abortion,” and “blighted ovum”. Many patients prefer the term “miscarriage” or “early pregnancy loss” (Clement 2019). Consider that the term “miscarriage” may be received by some patients as an implication that they are somehow at fault (i.e. for not “carrying” the pregnancy correctly).

EPL is very rarely a medical emergency, thus management most commonly and appropriately occurs in the outpatient setting, which is safe, efficient, and cost-effective, while also providing more choices for patients. While some emergency departments (EDs) have worked to build capability to manage EPL, the goal of most has been to evaluate for possible ectopic pregnancy, manage patients with hemodynamic instability, and defer management of stable definitive or potential EPL to the outpatient setting (ACEP 2012).

With an increasingly restrictive legislative environment, abortion and pregnancy outcomes including pregnancy loss and stillbirth are increasingly at risk of being criminalized, with patients at risk of being reported to law enforcement for presenting to the ED for care. Risk of criminalization may be higher among individuals from historically marginalized communities. Additionally, patients and providers in some religiously affiliated institutions may face additional barriers to managing EPL, particularly for inevitable abortion where there is still electronic cardiac activity (Freedman 2008).


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