Objective: To provide an evidence-based approach to guide the diagnosis and management of intrauterine early pregnancy loss.
Target population: This population includes patients experiencing pregnancy loss/miscarriage and incomplete pregnancy loss in the context of a normally sited intrauterine pregnancy. It does not include patients with a pregnancy of unknown location, ectopic pregnancy or recurrent pregnancy loss (2 or more pregnancy losses).
Benefits, harms, and costs: Incorrect diagnosis of a pregnancy loss increases the risk of harming a live, normally sited pregnancy. Prolonged waiting for confirmation of a diagnosis can increase anxiety and delay treatment. Patient-centred care discussions can help patients understand their pregnancy loss risk and make decisions about their management and follow-up, including time off for bereavement and mental health support.
Evidence: The following search terms were entered into PubMed from January 2021 to December 2024: early pregnancy loss, incomplete, spontaneous abortion, diagnosis, and management. The International Society of Ultrasound in Obstetrics and Gynecology (2021 and 2022), and Association of Early Pregnancy Units presentations and references were also used.
Validation methods: The authors rated the quality of evidence and strength of recommendations using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. See online Appendix A (Tables A1 for definitions and A2 for interpretations).
Intended audience: Health care providers who provide care to pregnant patients experiencing intrauterine early pregnancy loss.
Tweetable abstract: Early pregnancy loss is a common experience that can be traumatic. Patient-centred care in an Early Pregnancy Assessment Clinic can help patients make informed decisions.
SUMMARY STATEMENTS
1. Early pregnancy bleeding and loss are common reasons for health care visits (high).
2. Most early pregnancy loss results from aneuploidy and is not preventable or treatable (high).
3. Early pregnancy loss has significant psychosocial consequences for patients and their families that can include depression, anxiety and Post-Traumatic Stress Disorder (PTSD) (high).
4. The establishment of multidisciplinary Early Pregnancy Assessment clinics across the country is recommended; they improve patient experience by expediting evaluation of early pregnancy bleeding and providing physical and emotional care specific to EPL, reducing visits to the emergency department and surgical wait times (high).
5. Care for early pregnancy should be prioritized to provide patient-centred, evidence based care, reduce complications and manage the mental health needs of patients and their families (high).
6. Social circumstances, access to care, and patient preference influence management decisions. When diagnostic uncertainty is present, desiredness of the pregnancy can influence patient decision-making (high).
7. Canada lacks race-based data about early pregnancy outcomes, although data from other countries show inequities; this should be a consideration when providing care and a focus of research in the future (high).
8.When early pregnancy loss is diagnosed, medically stable patients can review all available management options (expectant, medical, procedural (surgical)) with support to make the decision best for them (high).
9. Successful medical management may avoid the need for a surgical procedure and the associated surgical and anesthetic risks; mifepristone and misoprostol should be free for patients who choose medical management (moderate).
10. Current evidence indicates that the amount of fetal blood in the maternal circulation does not reach a level to induce alloimmunization under 12 weeks of pregnancy and guidelines suggest consideration of RhIg administration between 10-12 weeks on an individual basis, in the context of shared decision-making about the potential benefits and risks (moderate).
11. Providing antibiotics prior to procedural (surgical) management of early intrauterine pregnancy loss with uterine aspiration and avoiding sharp curettage may reduce the risks of infection and intrauterine adhesions (moderate).
RECOMMENDATIONS
1. Ultrasound criteria should be used to diagnose intrauterine early pregnancy loss. (strong, high)
2. Clinicians should avoid using hCG values alone to diagnose normal intrauterine pregnancy as there is overlap between non-viable intrauterine pregnancy, viable intrauterine pregnancy, and ectopic pregnancy. (strong, high)
3. Clinicians should screen patients diagnosed with pregnancy loss for depression and offer treatment or referral to a mental health care provider when they have symptoms of depression. (strong, moderate)
4. Patients with no prior history of early pregnancy loss should be counselled that no known treatment can change the outcome of a threatened early pregnancy loss. (strong, high)
5. Patient health history (anemia, bleeding disorders, etc.), and proximity to a health care facility that can manage urgent and emergent complications should be considered when counselling patients on management options. (strong, high)
6. For stable patients with EPL without signs of infection, all available management options (expectant, medical, procedural) should be discussed. (strong, high)
7. Patients who choose expectant or medical management of early pregnancy loss should be counselled about the potential need for urgent intervention and provided with instructions on when and where to present for medical assessment if excessive bleeding, pain or signs and symptoms of infection occur. (strong, high)
8. Clinicians should use mifepristone and misoprostol or multidose misoprostol alone for medical management of early pregnancy loss (gestational sac present). (strong, high)
9. Expectant management has high success rates for incomplete Early Pregnancy Loss (thickened endometrium with no gestational sac present) and should be a first choice when the patient does not have heavy bleeding, significant pain, or infection. (strong, moderate)
10. Clinicians should use a misoprostol-only regimen when patients request medical management of incomplete Early Pregnancy Loss (thickened endometrium with no gestational sac present). (strong, high)
11. A definite intrauterine early pregnancy loss managed expectantly or medically that results in heavy bleeding which resolves can be followed clinically. Ultrasound +/- hCG levels can be reserved for clinical concerns: ongoing heavy bleeding, suspected infection, spotting > 3 weeks or amenorrhea > 8 weeks. (strong, moderate)
12.
Routine RhIg prophylaxis for early pregnancy loss at less than 12 weeks is not recommended (moderate). RhIg administration can be considered on an individual basis between 10-12 weeks in the context of a shared decision-making discussion about the potential benefits and risks. (conditional, moderate)
13. For surgical management, suction curettage is recommended. Sharp curettage should be minimized to reduce the risk of intrauterine adhesions (strong, moderate); antibiotic prophylaxis should be considered to reduce the risk of infection. (strong, moderate)
14. For a clinically complete Early Pregnancy Loss (heavy bleeding that has resolved), expectant management has a high success rate even if retained products are identified on ultrasound with no gestational sac present. (strong, moderate)
15.
Pregnant patients who have experienced a prior early pregnancy loss should be offered a reassurance ultrasound at 7 weeks GA to confirm pregnancy location and viability. (strong, low)
16.
Clinicians should create local health quality improvement initiatives to improve wait times for requested procedural management and reduce repeat visits to the emergency department. (strong, moderate)
Keywords
Keywords: abortion; early pregnancy loss; incomplete miscarriage; miscarriage; spontaneous abortion.
1. Intrauterine early pregnancy loss is common, occurring in approximately 15% of pregnancies, and can lead to significant psychological distress, including post-traumatic stress disorder (PTSD).
2. A patient-centred approach to diagnosis and management of early pregnancy loss takes into account the desiredness of pregnancy, social circumstances, access to care and patient preferences.
3. Ultrasound is the preferred first-line method for assessing bleeding during pregnancy, as it minimizes the risk of harm to a desired pregnancy. Canadian health care providers should provide compassionate, expedited care for people experiencing bleeding in the first trimester.
4. Early Pregnancy Assessment Clinics can provide patient-centred care for early pregnancy complications and should be established, supported, promoted and appropriately resourced across Canada utilizing standard practice models.
Definitions
Early Pregnancy Loss: Intrauterine pregnancy gestational sac has reached a stage where it has been diagnosed as non-viable based on ultrasound criteria, is in the cervix, or has passed through the cervix.
Early Pregnancy Loss (gestational sac present): Intrauterine gestational sac present and not protruding from cervix on speculum examination or ultrasound.
Threatened: Bleeding or cramping; cervix closed, no tissue visualized in the vagina; ultrasound may show viable pregnancy with fetal cardiac activity
Complete: Early pregnancy loss has passed, bleeding and cramping has subsided, and no intervention was required on follow-up (best diagnosed 6-8 weeks after passage)
Incomplete: Gestational sac has passed but symptomatic (bleeding, pain and/or infection) endometrial thickening
Introduction
It is estimated that around 15% of pregnancies end in EPL with rates varying based on age and the number of prior EPL.1,2 Many people who experience early pregnancy loss will present with vaginal bleeding during early pregnancy. Data from an Ontario hospital suggest that emergency department rates for the initial and reassessment of early pregnancy hemorrhage are 1.2% and 0.3%, respectively of all emergency department visits over a 10 year period. These patients often wait long hours in emergency departments/urgent care and are sent home without a diagnosis or treatment plan due to a lack of ultrasound availability.3 Patients often receive minimal or no emotional support once sent home.4 Patients living in rural Canadian communities generally have less access to resources (e.g., ultrasound or access to Obstetrician Gynaecologists) and may require transportation far from their local support networks to receive a diagnosis and treatment.5,6
Patients experiencing early pregnancy loss often avoid sharing this information with friends and family, increasing isolation and self-blame. While there are some modifiable causes of early pregnancy loss, most often there is nothing the patient could have done to impact the outcome, and misinformation is harmful.2
There is an association between pregnancy loss and anxiety, depression, and post-traumatic stress disorder.2,7–10
Although the current definition of recurrent pregnancy loss includes three or more consecutive unexplained first trimester EPLs, the Royal College of Obstetricians and Gynaecologists (RCOG) now encourages clinicians “to use their clinical discretion to recommend extensive evaluation after two first trimester EPLs if there is a suspicion that the EPLs are of pathological and not of sporadic nature.11
Canada can look to the United Kingdom (UK) as an example of how to improve care for patients experiencing early pregnancy loss.12 There are over 200 Early Pregnancy Assessment Clinics/Units throughout the UK that provide an alternative to the emergency department and allow for semi-urgent standardized outpatient assessments of non-urgent early pregnancy bleeding and complications.12
Canada has established Early Pregnancy Assessment Clinics in a few areas; however, more work is needed to expand and standardize care across our country. In a 2017 survey of Ontario emergency departments providing at least 30 000 visits per year, 54% did not have access to an Early Pregnancy Assessment Clinic.3 Care for early pregnancy should be prioritized to provide patient-centred, evidence based care, reduce complications and manage the mental health needs of patients and their families. There are regional differences in our diverse country, and a “one size fits all” approach may not be realistic.
This guideline addresses care for patients experiencing early pregnancy loss (EPL); it does not address the diagnosis and management of pregnancy of unknown location (PUL), ectopic pregnancy, or recurrent pregnancy loss.
Summary Statements 1, 2, 3,4 and 5
SUMMARY STATEMENTS
1. Early pregnancy bleeding and loss are common reasons for health care visits (high).
2. Most early pregnancy loss results from aneuploidy and is not preventable or treatable (high).
3. Early pregnancy loss has significant psychosocial consequences for patients and their families that can include depression, anxiety and Post-Traumatic Stress Disorder (PTSD) (high).
4. The establishment of multidisciplinary Early Pregnancy Assessment clinics across the country is recommended; they improve patient experience by expediting evaluation of early pregnancy bleeding and providing physical and emotional care specific to EPL, reducing visits to the emergency department and surgical wait times (high).
5. Care for early pregnancy should be prioritized to provide patient-centred, evidence based care, reduce complications and manage the mental health needs of patients and their families (high).
Diagnosis of Early Pregnancy Loss
Ultrasound is key to establishing pregnancy location and viability.13–15 Findings of an intrauterine gestational sac > 25 mm without an embryonic pole or an embryo with a crown rump length of 7 mm without a heartbeat on endovaginal scan are diagnostic of EPL (Box 1).17 Findings with measurements below these thresholds usually establishes intrauterine location but not viability, and follow-up ultrasound is indicated.
Box 1. Initial Endovaginal Ultrasound Scan Criteria
for Early Pregnancy Loss16
No visible embryo and a mean gestational sac diameter of 25mm
Embryo with no cardiac activity and a crown-rump length of 7mm
However, some patients who are uncertain about continuing the pregnancy or unable to attend follow-up appointments may wish to intervene with medical or surgical management despite diagnostic uncertainty. It is appropriate to offer these patients an intervention prior to obtaining a diagnosis of pregnancy loss with 100% certainty.
Endovaginal ultrasound can provide 100% certainty of pregnancy loss when performed by appropriately trained clinicians (Figure 1 and Box 1).16,18 When initial ultrasound scan criteria for EPL is not met, and an intrauterine pregnancy is highly likely, Figure 1 reviews optimal timing for a repeat ultrasound scan to make a diagnosis of viable pregnancy or pregnancy loss.
Figure 1Timeline of endovaginal ultrasound follow-up to determine pregnancy outcome when initial criteria for pregnancy loss not met.
Pregnancy of unknown location (PUL), Intrauterine pregnancy (IUP), early pregnancy loss (EPL).
1 Follow quantitative bhCG with suspected passage of gestational sac if no histologic (pathology) intrauterine pregnancy diagnosis or no prior ultrasound evidence of definite intrauterine pregnancy (yolk sac or embryo).
2 Consider waiting one more week if considerable doubling of mean sac diameter, consider patient with sac of 3 mm on initial scan still empty on repeat scan at 14 days -14.1 mm ended as viable.
3 Po L, Thomas J, Mills K, et al. Guideline No. 414: Management of Pregnancy of Unknown Location and Tubal and Nontubal Ectopic Pregnancies. J Obstet Gynaecol Can. 2021;43:614-30 e1. Available at https://www.ncbi.nlm.nih.gov/pubmed/3345337
However, some patients who are uncertain about continuing the pregnancy or unable to attend follow-up appointments may wish to intervene with medical or surgical management despite diagnostic uncertainty. It is appropriate to offer these patients an intervention prior to obtaining a diagnosis of pregnancy loss with 100% certainty.
Endovaginal ultrasound can provide 100% certainty of pregnancy loss when performed by appropriately trained clinicians (Figure 1 and Box 1).16,18 When initial ultrasound scan criteria for EPL is not met, and an intrauterine pregnancy is highly likely, Figure 1 reviews optimal timing for a repeat ultrasound scan to make a diagnosis of viable pregnancy or pregnancy loss.
Prior to the development of a yolk sac or embryo (definite IUP) there is at least a 97% certainty that any intrauterine sac-like structure on ultrasound will represent an IUP, especially if the sac is eccentric (i.e. intradecidual sac sign) or has 2 concentric echogenic rings (i.e. double decidual sac sign).19,20 In contrast, intrauterine fluid, associated with about 17% of ectopic pregnancies, is more commonly described as “pointy edged” (78%), with echoes or debris (74%), and within the uterine cavity.21 When only intrauterine fluid, a very small gestational sac (e.g., under 4 mm) or probable incomplete or complete early pregnancy loss is suspected with no prior ultrasound showing a gestational sac with yolk sac or embryo perform a quantitative hCG at diagnosis and repeat in 48 hours to estimate risk of ectopic pregnancy and guide follow-up (Figure 1).
Some non-viable gestational sacs do not develop a yolk sac. The absence of a yolk sac on endovaginal ultrasound inside a gestational sac with a mean sac diameter (i.e. the sum of measurements in 3 orthogonal planes divided by 3) of 8 mm, 12 mm, 16 mm, and 20 mm predicts a 73%, 83%, 90%, and 96% final diagnosis of early pregnancy loss, respectively.18 Similarly, the absence of cardiac activity in an endovaginal scan of an embryo with a crown rump length (CRL) of 3, 4, 5, and 6 mm predicts a pregnancy loss rate of 94%, 96%, 97%, and 98%, respectively.18 Slow heart activity (e.g. under 90 beats per minute prior to 6.3 weeks or under 110 beats per minute at 6.3 to 7 weeks) has been associated with a 60% risk of pregnancy loss. While knowledge of the probability of EPL has not been shown to reduce patients’ anxiety, it can provide psychological preparation. Using risk predictors for pregnancy loss can assist patients who do not require 100% certainty of pregnancy loss to make individual management decisions.
Bleeding and/or pelvic pain in early pregnancy has been shown to slightly increase the composite risk of antenatal complications in a prospective study of 826 patients (26% vs 17% with no pain or bleeding).22 The presence of a large first trimester subchorionic hemorrhage, especially when diagnosed before 7 weeks on ultrasound has been associated with an increased risk of pregnancy loss in some studies but results are conflicting.23,24 Subchorionic hematoma has also been associated with increased risk of preterm labour suggesting a need for increased vigilance during prenatal care. (adjusted odds ratio 1.94. 95% CI 1.07 to 3.52).23,25
Once a pregnancy is confirmed as intrauterine with cardiac activity, a repeat ultrasound should be considered if vaginal bleeding worsens or persists beyond 14 days. To avoid multiple emergency department visits, patients with higher levels of anxiety may benefit from more frequent assessment of viability with early referral to a health care provider that can perform point of care ultrasound and/or doptone where appropriate.
Decreasing serum hCG may help clarify the ultrasound diagnosis when uncertainty exists because hCG most commonly rises under 8 weeks of pregnancy. The hCG trajectory can aid in decision-making in situations when imaging is suspicious for, but not diagnostic of EPL and the patient does not wish to wait for, or may have difficulty accessing follow up ultrasound. In a prospective study of 107 patients with a symptomatic intrauterine pregnancy of uncertain viability (gestational sac but no embryo with cardiac activity; not meeting pregnancy loss criteria) an hCG ratio (hCG 48 hours after ultrasound divided by hCG at time of ultrasound) of less than 1.11 had a 100% specificity and positive predictive value to predict EPL in 24% of their study group.26 Human chorionic gonadotropin (hCG) levels range broadly and do not accurately differentiate between asymptomatic normal and abnormally developing pregnancies in patients under 45 days gestation.27 In normally developing pregnancies, the quantitative hCG levels plateau around 8-10 weeks, then drop, leading to potential harm of a wanted pregnancy when hCG trends are used without ultrasound to diagnose pregnancy loss.27 Ultrasound is necessary for diagnostic certainty.
Summary Statement 6 and Recommendations 1 and 2
SUMMARY STATEMENT
6. Social circumstances, access to care, and patient preference influence management decisions. When diagnostic uncertainty is present, desiredness of the pregnancy can influence patient decision-making (high).
RECOMMENDATIONS
1. Ultrasound criteria should be used to diagnose intrauterine early pregnancy loss. (strong, high)
2. Clinicians should avoid using hCG values alone to diagnose normal intrauterine pregnancy as there is overlap between non-viable intrauterine pregnancy, viable intrauterine pregnancy, and ectopic pregnancy. (strong, high)
Psychosocial and Communication Considerations
Rates of Early Pregnancy Loss and Racial Disparities
Research exploring disparities within EPL populations is limited but suggests that race may influence one’s risk of EPL. One report found that Black patients were 57% more likely to have experienced EPL compared to White patients;28 this difference persisted after adjustments for age and alcohol consumption. Similarly, a study in 2021 reported that Black race was associated with a higher risk of EPL when compared with White race.2 The contributing factors to these disparities remain largely unexplored.
There are few studies examining EPL rates in First Nations populations. Indigenous individuals may be at higher risk of EPL. In a prospective study of First Nations patients with pregestational type 2 diabetes, the baseline EPL rate was high at 27.7% likely due to multiple factors. The authors identified opportunities for management for the prevention of future EPLs including preconception and pregnancy support for smoking cessation, glycemic control, and weight management.29 Systemic factors (e.g. poverty, loss of cultural practices, and geographic segregation) may play a role in disparities in EPL rates among these populations. Data exploring the association between EPL rates and various racial and ethnic groups in Canada is very limited and further research is needed to elucidate this.
Summary Statement 7
7. Canada lacks race-based data about early pregnancy outcomes, although data from other countries show inequities; this should be a consideration when providing care and a focus of research in the future (high).
Early Pregnancy Loss and Mental Health Implications
EPL is associated with poor psychological outcomes that can persist for months after the loss.7,30 Patients who experience EPL have higher rates of depression, anxiety, obsessive-compulsive disorder, and post-traumatic stress disorder (PTSD).31–33 A study looking at the diagnosis of major depressive disorder after pregnancy loss found that 10.9% of patients met the criteria for depression, which was 2.5 times higher than for non-pregnant patients. In a prospective multicentre cohort study, PTSD (29%), anxiety (24%) and depression (11%) were present in individuals who had recently experienced pregnancy loss, and these mental health states persisted 9 months later at rates of 18%, 17% and 6% respectively.34
In a planned secondary analysis of a randomized controlled trial comparing medication regimens for the management of EPL, Shorter et al. found that 24% of people were at risk for major depression 30 days after EPL. Black participants experienced depression more than twice as often as non-Black participants (adjusted odds ratio: 2.48, 95% CI 1.28-4.81) when controlled for baseline depression, adverse childhood events score, and parity.10
Grief after EPL may be similar to that following the loss of any loved one. Guilt with underlying self-blame was found to be the strongest aspect of grief and required the longest time to resolve. Evidence suggests increased risk for depression and PTSD after EPL and the psychosocial support offered should be similar in these situations.15,30 Clinicians should consider the need for time off for grieving patients experiencing EPL, and should offer psychosocial support resources for patients, ideally in the patient’s first language.
Adverse mental health outcomes are common in EPL and are present in up to 30% of people one month after experiencing EPL.34 This indicates a need for mental health screening and appropriate mental health resources for patients undergoing care for EPL. Individuals displaying depressive symptoms, symptoms of grief or psychological distress, and/or anyone with a positive depression screen should be offered treatment for depression and be referred for mental health care services.35
Recommendation 3
3. Clinicians should screen patients diagnosed with pregnancy loss for depression and offer treatment or referral to a mental health care provider when they have symptoms of depression. (strong, moderate)
