By Rebecca H. Allen, MD, MPH, Editor
Early pregnancy loss (EPL) typically is defined as a miscarriage diagnosed prior to 12 weeks and 6 days gestation. This may represent a missed abortion/embryonic demise or a blighted ovum/anembryonic demise. Many patients are diagnosed with early pregnancy loss through a dating ultrasound prior to developing any symptoms of vaginal bleeding or abdominal pain. EPL is estimated to occur in between 15% and 20% of all pregnancies.1 The most common cause of EPL is genetic and caused by fetal chromosomal abnormalities.
Guidelines for Diagnosing Early Pregnancy Loss
As stated previously, the diagnosis of EPL most often is determined by ultrasound. In 2013, the Society of Radiologists in Ultrasound developed very conservative guidelines for the definitive diagnosis of EPL.2 In essence, the guidelines were designed to have 100% specificity for the diagnosis of failed pregnancy. The guidelines state that an embryonic crown rump length (CRL) of 7 mm or greater with no cardiac activity and a gestational sac with a mean sac diameter (MSD) of 25 mm or greater with no fetal pole is diagnostic of a missed abortion. However, over time, these guidelines have been criticized as being too strict and not patient-centered.3 There is ample evidence that a CRL of 5.3 mm or greater with no cardiac activity and an empty gestational sac with an MSD of 21 mm have sufficient certainty for the diagnosis.4
The new Society of Family Planning clinical recommendation, Medication Management for Early Pregnancy Loss, states that “while a definitive diagnosis of an EPL may be prioritized by some patients, other patients might prioritize expedited pregnancy resolution.”5 In essence, some patients may want to wait for a repeat ultrasound to confirm the diagnosis of failed pregnancy while others may not, either because they do not desire the pregnancy or they do not want to experience the uncertainty of waiting. Quantitative serum human chorionic gonadotropin (hCG) levels that are declining also may be helpful in more rapid diagnosis of a failed pregnancy rather than waiting for repeat ultrasounds.
Options in Managing Early Pregnancy Loss
Patients have three different management options for early pregnancy loss, provided there is no concern for a septic abortion or hemorrhage: expectant management, medical management, and procedural management (manual vacuum aspiration or suction dilation and curettage). All options are safe. The choice depends on patient preference regarding the need for surgery, anesthesia, and timing of resolution of the pregnancy.5
Expectant Management
Expectant management is an option that is estimated to be 80% successful but may take six to eight weeks. Patients should be monitored during this time to ascertain whether pregnancy expulsion has occurred. Patients may always switch to more active management if they tire of waiting. Of course, any concerning symptoms during the waiting period, such as fever, severe abdominal pain, or an abnormal amount of heavy vaginal bleeding, should be evaluated.
New data have emerged regarding the use of Rh immunoglobulin (Rhogam) for patients who are Rh-negative at less than 12 weeks of gestation. Most organizations, including the Society of Family Planning, the American College of Obstetricians and Gynecologists, the National Abortion Federation, and the World Health Organization, now do not recommend Rh testing and Rh immunoglobulin administration before 12 weeks in patients undergoing induced abortion or the treatment of miscarriage.1,6 Only the Society of Maternal-Fetal Medicine still recommends this intervention.
Medical Management
Medical management of EPL ideally consists of mifepristone 200 mg followed by 800 mcg of buccal or vaginal misoprostol seven to 48 hours later.5 If mifepristone is available, this regimen should be used because it is associated with the highest success rate (84%).7 It is important to note that this success rate is much lower than mifepristone and misoprostol for induced abortion. If only misoprostol is available, then the regimen should be two or more doses of misoprostol 600 mcg to 800 mcg sublingually, buccally, or vaginally at intervals of at least three hours. The success rate for misoprostol alone is estimated to be 67%.7
Pain control recommendations include the use of nonsteroidal anti-inflammatory drugs (NSAIDs), such as 800 mg of ibuprofen every eight hours as needed.5 Other medications may be needed on a case-by-case basis depending on patient characteristics. All patients should have a follow-up to confirm a completed abortion, whether this be in-person, via ultrasound, or through hCG testing at appropriate intervals. Follow-up ultrasound should be performed to document the absence of the gestational sac only. Studies have shown that there is no endometrial thickness that predicts the need for surgical intervention; rather, ultrasound findings should be correlated with patient symptoms, if any. Routine antibiotics are not required for expectant or medical management of EPL.8
Procedural Management
Procedural management is an option that appeals to patients because it is 99% effective in emptying the uterus and provides a quick resolution to the pregnancy.1 The procedure can be done in the outpatient setting, emergency department, or hospital. The level of anesthesia will depend on patient preference and what is available at the facility. Some patients may opt for the procedure with NSAIDs and local anesthesia (paracervical block) alone, while others may desire moderate or deep intravenous sedation. Universal antibiotic prophylaxis is recommended for both induced abortion procedures and treatment of EPL.8 Antibiotics should be given prior to the procedure, ideally with adequate time for absorption. Options include azithromycin 500 mg orally once or doxycycline 200 mg orally once. Metronidazole 500 mg orally once is a second-line option that can be used if there are allergies to the first-line options.
Summary
In conclusion, shared decision-making with patients regarding their preferences for the diagnosis and management of early pregnancy loss is essential. Some patients might prioritize the quickest resolution of the pregnancy possible, while others may opt for expectant management to avoid any intervention with an early pregnancy loss.
When medical management is being considered, regimens with mifepristone are superior to those with misoprostol alone. Therefore, advocacy to ensure continued access to mifepristone is essential. The medication can now be dispensed by retail pharmacies, provided the pharmacy has registered with the manufacturer with a doctor’s prescription. Nevertheless, with the 2022 U.S. Supreme Court decision in Dobbs v. Jackson Women’s Health Organization, the availability of mifepristone for medication management of EPL may depend on state law and the interpretation of these regulations.
Rebecca H. Allen, MD, MPH, is Professor, Department of Obstetrics and Gynecology, Warren Alpert Medical School of Brown University, Women & Infants Hospital, Providence, RI.
References
1. American College of Obstetricians and Gynecologists. Early pregnancy loss. Practice Bulletin Number 200. Published November 2018. https://www.acog.org/clinical/clinical-guidance/practice-bulletin/articles/2018/11/early-pregnancy-loss
2. Doubilet PM, Benson CB, Bourne T, et al. Diagnostic criteria for nonviable pregnancy early in the first trimester. N Engl J Med. 2013;369(15):1443-1451.
3. Judge-Golden C, Flink-Bochacki R. The burden of abortion restrictions and conservative diagnostic guidelines on patient-centered care for early pregnancy loss. Obstet Gynecol. 2021;138(3):467-471.
4. Abdallah Y, Daemen A, Kirk E, et al. Limitations of current definitions of miscarriage using mean gestational sac diameter and crown-rump length measurements: A multicenter observational study. Ultrasound Obstet Gynecol. 2011;38(5):497-502.
5. Tarleton JL, Benson LS, Moayedi G, et al. Society of Family Planning clinical recommendation: Medication management for early pregnancy loss. Contraception. 2025;144:110805.
6. [No authors listed]. ACOG Clinical Practice Update: Rh D immune globulin administration after abortion or pregnancy loss at less than 12 weeks of gestation. Obstet Gynecol. 2024;144(6):e140-e143.
7. Schreiber CA, Creinin MD, Atrio J, et al. Mifepristone pretreatment for the medical management of early pregnancy loss. N Engl J Med. 2018;378(23):2161-2170.
8. Cheng T, Kumar N, Laursen L, et al. Society of Family Planning clinical recommendation: Prevention of infection after abortion and pregnancy loss. Contraception. 2025; Mar 26. doi: 10.1016/j.contraception.2025.110895. [Online ahead of print].
Early pregnancy loss affects 15% to 20% of pregnancies and typically is diagnosed via ultrasound. Management options — expectant, medical, or procedural — should be tailored to patient preference. For medical management, mifepristone combined with misoprostol offers the highest success. Routine Rh testing before 12 weeks is no longer broadly recommended. Shared decision-making and access to effective medications remain critical.
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