Fetal loss in threatened abortion after embryonic/fetal heart activity

Assessing the predictive value of first trimester ultrasound and biochemical markers in miscarriage: A scoping review

INTRODUCTION

Vaginal bleeding in the first trimester of pregnancy generates anxiety and uncertainty for expecting parents. The ability to determine pregnancy outcome through a first trimester ultrasound scan remains a challenge in obstetrics. Several first trimester ultrasound markers used individually or in combination, as well as ultrasound markers used in combination with biochemical markers, have been studied to determine their predictive value in pregnancy outcome. This scoping review was performed to determine which markers have already been investigated for this purpose.

METHODS

An extensive and systematic database search was performed using four different categories of keywords which were combined using Boolean terms. A total of 14 variables were included on the final data charting forms. Data was synthesised collectively for each variable and then separately for the studies analysing only one marker. For the studies which analysed multiple markers, data was synthesised based on the number of markers per study.

RESULTS

The search yielded 3608 studies, of which 128 were ultimately used for this review. Data extraction, based on predetermined eligibility criteria, was performed by two authors independently. Seventy-seven (62.6%) studies investigated the predictive value of a single ultrasound marker. The remaining 46 (37.4%) studies explored multiple markers, of which at least one was an ultrasound marker.

CONCLUSION

This review identified several discrepancies among different studies. This highlights the need for better consensus among researchers to allow for the design of a predictive model which enables extrapolation of findings to all pregnant women.

IMPLICATIONS FOR PRACTICE

Through the study of ultrasound and biochemical markers in the first trimester of pregnancy, clinicians may provide a more accurate prediction of pregnancy outcome following threatened miscarriage.

First-Trimester Pregnancy: Considerations for Wilderness and Remote Travel

Women increasingly participate in outdoor activities in wilderness and remote environments. We performed a literature review to address diagnostic and therapeutic considerations during first-trimester pregnancy for remote multiday travel. Pretrip planning for pregnant patients traveling outside access to advanced medical care should include performing a transvaginal ultrasound to confirm pregnancy location and checking D rhesus status. We discuss the risk of potential travel-related infections and recommended vaccinations prior to departure based on destination. Immediate evacuation to definitive medical care is required for patients with a pregnancy of unknown location and vaginal bleeding. We propose algorithms for determining the need for evacuation and present therapeutic options for nausea and vomiting, urinary tract infections, and candidiasis in the field.

Vanishing twin syndrome is associated with first-trimester intrauterine hematoma in twin pregnancies after in vitro fertilization

RESEARCH QUESTION

Is there an association between intrauterine hematoma (IUH), vanishing twin syndrome (VTS), and subsequent complications in twin pregnancies after in vitro fertilization (IVF)? What are the risk factors for these complications?

DESIGN

Women who presented with two live gestational sacs following double embryo transfer were included. Patients with systematic diseases, artificial fetal reduction, and incomplete data were excluded. Further stratification of IUH pregnancies was performed according to IUH-related characteristics (i.e., volume, changing pattern, and relationship with fetal cardiac activities). The primary outcome was the incidence of VTS, while adverse outcomes in the surviving singleton and the gestational age of VTS were secondary outcomes.

RESULTS

The incidence of IUH was 13.8%. A total of 1,078 twin pregnancies including 539 IUH pregnancies and 539 non-IUH pregnancies were included. IUH pregnancy was associated with higher risks of VTS (26.9% vs. 18.7%, p = 0.001) as well as a higher incidence of preterm birth (p = 0.001, crude OR = 1.98, 95% CI 1.28-3.09, adjusted OR = 1.19, 95% CI 1.09-1.24), threatened abortion (p < 0.001, crude OR = 9.12, 95% CI 2.90-28.69, adjusted OR = 6.63, 95% CI 1.69-14.67), and postpartum hemorrhage (p = 0.024, crude OR = 3.13, 95% CI 1.09-8.99, adjusted OR = 1.16, 95% CI 1.08-1.32) in the surviving singleton. There was no significant difference in risks of other complications. The absence of fetal cardiac activities at the diagnosis of IUH predicted VTS (p < 0.001, crude OR 4.67, 95% CI 3.67-5.78, adjusted OR 3.33, 95% CI 1.56-5.14) and fetal loss at smaller gestational age (7.81 ± 2.10 vs. 11.39 ± 5.60 weeks, p < 0.001), while an IUH with an increasing volume did not increase the risk of VTS but might induce threatened abortion in the surviving fetus (p < 0.001, crude OR 1.84, 95% CI 1.32-2.55, adjusted OR 1.72, 95% CI 1.13-2.13).

CONCLUSIONS

IUH was a risk factor for VTS in twin pregnancies following double embryo transfer and elevated the risks of threatened abortion, preterm birth, and postpartum hemorrhage in the surviving singleton. The absence of fetal cardiac activities at the diagnosis of IUH elevated the risks of VTS, while an IUH with an increasing volume was associated with threatened abortion without elevating the risks of VTS. An IUH diagnosed before the presence of fetal cardiac activities also resulted in an earlier miscarriage. The study suggests that attention be paid to twin pregnancies with first-trimester IUH to prevent VTS and subsequent adverse perinatal outcomes.

HIGHLIGHTS

First-trimester intrauterine hematoma (IUH) following double embryo transfer is associated with a higher incidence of vanishing twin syndrome (VTS) and elevated subsequent risk of threatened abortion, preterm birth, and postpartum hemorrhage in the surviving singleton. Other perinatal outcomes were not associated with the diagnosis of first-trimester IUH. The absence of fetal cardiac activities at the diagnosis of IUH was of predictive value toward VTS, while an IUH with an increasing size was associated with threatened abortion without elevating the risk of VTS. Incomplete fetal cardiac activities and earlier detection of an IUH might also predict miscarriage at smaller gestational age.

Long-term risk of epilepsy, cerebral palsy and attention-deficit/hyperactivity disorder in children affected by a threatened abortion in utero

BACKGROUND

The birth of a child affected by a threatened abortion (TAB) in utero is associated with autism spectrum disorder; association with other neurological disorders is unknown.

METHODS

This nationwide registry-based cohort study included singletons live-born in Denmark (1979-2010), followed through 2016. The outcomes were epilepsy, cerebral palsy (CP) and attention-deficit/hyperactivity disorder (ADHD). We used Cox regression to compute hazard ratios (HRs), adjusted for birth year, birth order, parental age, morbidity, medication use and maternal socio-economic factors. To remove time-invariant family-shared confounding, we applied sibling analyses.

RESULTS

The study population included 1 864 221 singletons live-born in 1979-2010. Among the TAB-affected children (N = 59 134) vs TAB-unaffected children, at the end of follow-up, the cumulative incidence was 2.2% vs 1.6% for epilepsy, 0.4% vs 0.2% for CP and 5.5% vs 4.2% for ADHD (for children born in 1995-2010). The adjusted HRs were 1.25 [95% confidence interval (CI) 1.16-1.34] for epilepsy, 1.42 (95% CI 1.20-1.68) for CP and 1.21 (95% CI 1.14-1.29) for ADHD. In the sibling design, the adjusted HRs were unity for epilepsy (full siblings: 0.96, 95% CI 0.82-1.12; maternal: 1.04, 95% CI 0.90-1.20; paternal: 1.08, 95% CI 0.93-1.25) and ADHD (full: 1.08, 95% CI 0.92-1.27; maternal: 1.04, 95% CI 0.90-1.20; paternal: 1.08, 95% CI 0.93-1.25). For CP, HRs shifted away from unity among sibling pairs (full: 2.92, 95% CI 1.33-6.39; maternal: 2.03, 95% CI 1.15-3.57; paternal: 3.28, 95% CI 1.36-7.91).

CONCLUSIONS

The birth of a child affected by TAB in utero was associated with a greater risk of CP, but not epilepsy or ADHD.

Clinical and Ultrasound Evaluation of Early Threatened Miscarriage to Predict Pregnancy Continuation up to 28 Weeks: A Prospective Cohort Study

OBJECTIVES

(1) To study the predictors of pregnancy continuation up to 28 weeks in first-trimester threatened miscarriage after a single clinical and ultrasound (US) evaluation. (2) To assess the role of both clinical and US predictors in counseling and decreasing repeated emergency follow-up scans.

METHODS

A prospective observational study that included a cohort of 241 patients with threatened miscarriage (≥6-12 weeks) was conducted. They had a single clinical and US evaluation, and then they were contacted by weekly phone calls until completing 28 weeks' gestation or reporting miscarriage. Independently, all patients were followed by the recommended routine US scanning with or without emergency visits.

RESULTS

Two hundred thirty-three patients completed the study, of whom 193 patients continued up to 28 weeks' gestation, and 40 miscarried (17.1%). Only spotting/mild bleeding episodes and progesterone treatment were the clinical predictors of fetal viability. The embryonic/fetal heart rate (E/FHR) was the best single US predictor, with a specificity and positive predictive value of 95.3% and 97.2%, respectively. Combining 3 US parameters, at their best cutoff points (E/FHR >113 beats per minute, crown-rump length >19.9 mm, and gestational sac diameter >27.3 mm), had a specificity and positive predictive value of 98% and 99% (first-trimester US triad of fetal viability).

CONCLUSIONS

[1] In first-trimester threatened miscarriage, clinical parameters that could predict fetal viability included spotting/ mild bleeding and progesterone treatment. [2] After a single US scan, the presence of at least an E/FHR of greater than 113 bpm or the suggested first-trimester US triad appeared as a simple, measurable, and effective predictor of pregnancy continuation up to 28 weeks. [3] These US predictors are not to replace the recommended scheduled scanning during pregnancy. [4] This can improve patients' counseling and decrease the need for repeated emergency follow-up scans. Otherwise, there is an indication for repeating US scans at a 1-week to 10-day interval.

Correlation of Serum CA-125 and Progesterone Levels with Ultrasound Markers in The Prediction of Pregnancy Outcome in Threatened Miscarriage

Background

The aim of this study was to evaluate the relationship between ultrasonographic findings and serum progesterone and cancer antigen-125 (CA-125) levels in threatened miscarriage and to predict pregnancy outcome.

Materials and Methods

In a prospective comparative case-control study, serum CA-125 and progesterone levels were measured for 100 pregnant women with threatened miscarriage who attended the outpatient clinic or the causality department of Obstetrics and Gynecology at Kasr El-Aini Hospital, Giza, Egypt, during the period from March 2013 to October 2013. Ultrasound was performed for fetal viability, crown-rump length (CRL), gestational sac diameter (GSD) and fetal heart rate (FHR). The patients were followed up and divided into two groups based on the outcome: 20 women who miscarried (group 1), and 80 women who continued pregnancy (group 2). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy were tested for CA-125 and progesterone levels in prediction of the pregnancy outcome. Correlation of these chemical markers with the ultrasound markers was also examined.

Results

In the group that miscarried, CA-125 level was significantly higher (P<0.001) and serum progesterone level was significantly lower (P<0.001). For prediction of the outcome of pregnancy, the cut-off limit of 31.2 IU/ml for CA-125 level yielded sensitivity, specificity and an overall accuracy of 96.2, 100 and 99.4% respectively. The cut-off limit of 11.5 ng/ml for progesterone level yielded sensitivity, specificity and an overall accuracy of 97.5, 100 and 99.8% respectively. CA-125 level had a negative correlation with progesterone level and FHR levels (r=-0.716, P<0.001) and (r=-0.414, P<0.001) respectively. Serum progesterone level correlated with GSD (r=0.521, P<0.001) and with CRL (r=0.407, P<0.001) and FHR (r=0.363, P<0.001). CA-125 level was significantly higher in the group that showed hematoma as compared with the group without hematoma (P<0.001). Also, serum progesterone level was significantly lower in the group that showed hematoma as compared with the group without hematoma (P=0.017).

Conclusion

Serum CA-125 and progesterone levels are valid early predictors of the outcome of pregnancy in women with threatened miscarriage. They are correlated with some ultrasonographic markers (GSD, CRL, and FHR).

Validation of ICD-9 Codes for Stable Miscarriage in the Emergency Department

Introduction

International Classification of Disease, Ninth Revision (ICD-9) diagnosis codes have not been validated for identifying cases of missed abortion where a pregnancy is no longer viable but the cervical os remains closed. Our goal was to assess whether ICD-9 code “632” for missed abortion has high sensitivity and positive predictive value (PPV) in identifying patients in the emergency department (ED) with cases of stable early pregnancy failure (EPF).

Methods

We studied females ages 13–50 years presenting to the ED of an urban academic medical center. We approached our analysis from two perspectives, evaluating both the sensitivity and PPV of ICD-9 code “632” in identifying patients with stable EPF. All patients with chief complaints “pregnant and bleeding” or “pregnant and cramping” over a 12-month period were identified. We randomly reviewed two months of patient visits and calculated the sensitivity of ICD-9 code “632” for true cases of stable miscarriage. To establish the PPV of ICD-9 code “632” for capturing missed abortions, we identified patients whose visits from the same time period were assigned ICD-9 code “632,” and identified those with actual cases of stable EPF.

Results

We reviewed 310 patient records (17.6% of 1,762 sampled). Thirteen of 31 patient records assigned ICD-9 code for missed abortion correctly identified cases of stable EPF (sensitivity=41.9%), and 140 of the 142 patients without EPF were not assigned the ICD-9 code “632”(specificity=98.6%). Of the 52 eligible patients identified by ICD-9 code “632,” 39 cases met the criteria for stable EPF (PPV=75.0%).

Conclusion

ICD-9 code “632” has low sensitivity for identifying stable EPF, but its high specificity and moderately high PPV are valuable for studying cases of stable EPF in epidemiologic studies using administrative data.

A systematic review of dydrogesterone for the treatment of threatened miscarriage

The objective of this systematic review was to assess whether the orally acting progestagen, dydrogesterone lowers the incidence of miscarriage in women with threatened miscarriage. A computerized search was performed in Medline, Embase, and Ovid Medline for original reports with the product name 'Duphaston' or 'dydrogesterone', and limited to clinical human data. Twenty-one reports of dydrogesterone treatment were identified with 1380 patients. Five randomized trials were identified, including 660 women who fulfilled the criteria for meta-analysis. The number of subsequent miscarriages or continuing pregnancies per randomized woman was compared in women receiving dydrogesterone compared to standard bed rest or placebo intervention. There was a 13% (44/335) miscarriage rate after dydrogesterone administration compared to 24% in control women [odds ratio for miscarriage 0.47, (CI = 0.31-0.7), 11% absolute reduction in the miscarriage rate]. The adverse and side effects were summarized in all 21 reports, and seemed to be minimal. Although all the predictive and confounding factors could not be controlled for, the results of this systematic review show a significant reduction of 47% in the odds for miscarriage when dydrogesterone is compared to standard care indicating a real treatment effect.

Fetal loss in threatened abortion after demonstration of fetal cardiac activity in a low socioeconomic population

This study was conducted to determine the incidence and risk factors of fetal loss in threatened abortion after ultrasonographic detection of fetal cardiac activity in a low socioeconomic population. A total of 202 women with singleton pregnancies who presented with vaginal bleeding in which fetal heart activity was ultrasonographically demonstrated between 5 and 14 weeks' gestation were included. Pregnancies with fetal abnormalities were excluded from the study. All cases were followed-up with respect to pregnancy outcomes. A total of 54 of 202 pregnancies (26.7%) resulted in fetal loss before 20 weeks' gestation. The mean fetal heart rate (FHR) and cervical length values were lower in spontaneous abortions than in viable pregnancies (121.2 +/- 13.3 vs 143.5 +/- 12.4 and 41 +/- 6.0 vs. 34.8 +/- 6.1, respectively; p < 0.001). A receiver operating characteristic (ROC) curve analysis revealed an area under the curve of 0.88 for FHR and 0.77 for cervical length. A FHR value <130 b.p.m. was 81.4% sensitive, 85.1% specific and a cervical length value <40 mm was 80.8% sensitive, 54.7% specific for determination of fetal loss before 20 weeks' gestation. Fetal loss was observed in about one-quarter of pregnancies admitted with threatened abortion in a low socioeconomic population. Bradycardia and short cervix were found to be significant risk factors affecting the pregnancy outcome in women presenting with vaginal bleeding, in whom fetal cardiac activity was documented.

Auscultation of the fetal heart in early pregnancy

INTRODUCTION

Auscultation of the fetal heart is a common event in antenatal care, in early pregnancy it may be associated with false negative results, which require ultrasound scan to confirm fetal viability.

METHODS

We studied 197 women in early pregnancy to determine the gestational age at which the fetal heart can be reliably identified and the factors which determined the accuracy of the test.

RESULTS

The proportion of successful auscultations increased with advancing gestation (p < 0.001). There was no effect of maternal body mass index or the level of midwifery experience.

CONCLUSION

For a sensitivity of 90%, the fetal heart should be auscultated after 13 week gestation. If a sensitivity of 80% is acceptable the fetal heart can be auscultated after 12 + 1 week gestation.

Yolk sac size and embryonic heart rate as prognostic factors of first trimester pregnancy outcome

OBJECTIVES

To investigate embryonic heart rate (EHR) and yolk sac diameter (YSD) during the first trimester and their role as prognostic markers of first trimester pregnancy outcome.

STUDY DESIGN

Prospective cohort study involving 219 women conducted in the 4th Academic Department of Obstetrics and Gynaecology, Aristotle University of Thessaloniki, Greece. Gestational age (GA) was determined ultrasonographically based on gestational sac diameter and crown-rump length. EHR and YSD were evaluated during the first 12 weeks and subsequently compared between the pregnancies that continued beyond the first trimester and those that resulted in spontaneous abortion. Receiver-operating characteristic (ROC) curves were used for the evaluation of the prognostic value of the combination of gestational age with embryonic heart rate and yolk sac diameter.

RESULTS

The EHR and YSD were significantly correlated to advancing gestational age (p<0.001) in pregnancies continuing beyond 12 weeks. Pregnancies that resulted in spontaneous abortion exhibited a statistically significant lower EHR (p<0.001), smaller YSD (p=0.001) or absent yolk sac. ROC curve analysis demonstrated the predictive value of the combination of GA with EHR (area under the ROC curve: 0.971, p<0.001) and GA with YSD (area under the ROC curve: 0.858, p<0.001) for first trimester pregnancy outcome.

CONCLUSIONS

EHR and YSD progressively increase in healthy pregnancies during the first trimester. Embryonic bradycardia and absence of yolk sac or even a smaller yolk sac diameter than expected for any gestational age are predictors of poor pregnancy outcome during the first 12 weeks.

Correlation of maternal plasma total cell-free DNA and fetal DNA levels with short term outcome of first-trimester vaginal bleeding

BACKGROUND

The current methods using sonographic parameters and/or maternal serum beta-HCG levels to predict spontaneous abortion are not satisfactory. The aim of this study was to determine whether maternal plasma fetal DNA and total DNA levels could be used to predict spontaneous abortion.

METHODS

We prospectively studied pregnant women who presented with vaginal bleeding in the first trimester of pregnancy, and those who had no vaginal bleeding (controls). DYS14 and the beta-globin gene were used to measure the maternal plasma levels of fetal and total DNA, respectively, by real-time PCR.

RESULTS

A total of 1114 women were studied. Both maternal plasma fetal and total DNA concentrations increased with gestation from 6 to 11.6 weeks in the controls. The multiple of medians (MoMs) of fetal and total DNA concentration in those who miscarried were significantly greater (P < 0.001) than in the normal controls by about 5- and 4-fold respectively. Using a cut-off value of 1.6 MoMs for total DNA to predict spontaneous abortion, the sensitivity was 98.2% and false positive rate was 4.7%. However, using a cut-off value of 1.8 MoMs for fetal DNA, the corresponding figures were 97% and 44.3%, respectively.

CONCLUSIONS

Both maternal plasma fetal and total DNA concentrations increased throughout the first trimester. Significantly high levels of fetal and total DNA were found in those who miscarried.

Common problems and emergencies in the obstetric patient

Physicians not used to caring for pregnant patients may feel uncomfortable dealing with the many routine problems that can occur during a pregnancy. Other than true obstetric emergencies, which are usually cared for by obstetricians and family physicians, and the common problems of pregnancy can often be cared for by any primary care physician. Given the litigious nature of our society, especially in the realm of obstetrics, it does behoove the physician caring for pregnant women to be aware of the standards of care. When in doubt, it would be prudent to consult with a physician that routinely provides care to pregnant women.

Emergency gynaecology

The management of gynaecological emergencies is directed at the preservation of life, health, sexual function and the perpetuation of fertility. Ectopic pregnancy (EP), pelvic inflammatory disease (PID) and miscarriages are common gynaecological emergencies and early recognition and appropriate treatment is essential to avoid unwanted sequelae. Controversy will always exist in clinical medicine because management is mainly based on uncontrolled studies, expert opinion and personal experiences. It is estimated that only 10% of clinical treatments have been validated by prospective, randomised trials. Recent advances have led to earlier diagnosis and more conservative treatment on an outpatient or day care basis in EP and miscarriages.

First trimester threatened miscarriage treatment with human chorionic gonadotrophins: a randomised controlled trial

OBJECTIVE

To determine whether administration of exogenous human chorionic gonadotrophin (hCG) treatment improve the pregnancy outcome in first trimester threatened miscarriages.

DESIGN

A prospective, double blind, randomised, placebo-controlled trial.

SETTING

The Early Pregnancy Assessment Unit, Royal Bolton Hospital, Bolton, United Kingdom.

POPULATION

One hundred and eighty-three women with vaginal bleeding and a viable fetus seen on ultrasound scan (USS) in the first 12 weeks of pregnancy.

METHODS

The patients were randomised to receive either hCG or placebo treatment until 14 weeks of gestation.

MAIN OUTCOME MEASURES

The primary objective of the trial was to determine the miscarriage rate in the hCG arm compared from the placebo arm.

RESULTS

Of the 183 cases, 87 were randomised to treatment with hCG while 96 were randomised to receive a placebo. Forty-seven (25%) did not comply with the study protocol. The mean [SD] gestational age at presentation was 7 [1.33] weeks. The mean [SD] age of women in study was 27 [5] years in the placebo and 28 [5] in the hCG group. The mean body mass index (kg/m(2)) was 25 [5] in the study. The number of patients actively bleeding per vaginum at presentation was 85 (93%) in placebo group and 79 (96%) in the hCG group. The median number of hCG or placebo injections for both groups was 7. Ten women (11%) in the placebo group proceeded to have a complete miscarriage, as did 10 women (12%) in the hCG group, relative risk (RR) [95% confidence interval (CI)] of 1.1 (0.63-1.6).

CONCLUSION

Our study showed no evidence of a difference in the outcome of threatened miscarriages when treated with hCG in the first trimester, this may be because our study sample size was small and follow up was suboptimal. A large, randomised, multicentre trial is still needed to establish the usefulness of hCG treatment in cases of threatened miscarriage.

The role of ultrasound imaging in diagnosing and investigating early pregnancy failure

The advent of high-resolution transvaginal ultrasound (TVS) has revolutionized our understanding of the pathophysiology and the management of early pregnancy failure. Knowledge of the ultrasound appearances of normal early pregnancy development and a good understanding of its pitfalls are essential for the diagnosis and management of early pregnancy failure. Ultrasound imaging has rapidly replaced all other techniques used to study normal human development in the first trimester, and ultrasound features of the early gestational sac have corroborated anatomical studies showing that the first structures to appear are the celomic cavity and the secondary yolk sac. No single ultrasound measurement of the different anatomical features in the first trimester has been shown to have a high predictive value for determining early pregnancy outcome. Similarly, Doppler studies have failed to demonstrate abnormal blood flow indices in the first-trimester uteroplacental circulation of pregnancies that subsequently end in miscarriage. Ultrasound parameters combined with maternal serum hormone levels, maternal age, smoking habits, obstetric history and the occurrence of vaginal bleeding have all been combined in multivariate analyses, with mixed results. Combined ultrasound and in-vitro experiments have demonstrated that the maternal circulation inside the placenta starts at the periphery at around 9 weeks of gestation and that this is associated with a physiological oxidative stress which could be the trigger for the formation of the placental membranes. Abnormal development of these membranes can result in subchorionic hemorrhage and threatened miscarriage with subsequent long-term consequences such as preterm rupture of the membranes and preterm labor, irrespective of the finding of a hematoma on ultrasound. In both euploid and aneuploid missed miscarriages there is clear ultrasound evidence for excessive entry of maternal blood at a very early stage inside the developing placenta resulting in oxidative stress and subsequent degeneration of villous tissue. The finding of blood flow in the intervillous space in cases of first-trimester miscarriage using color Doppler also appears to be useful in the prediction of success of expectant management. Miscarriages with blood flow within the intervillous space are up to four times more likely to complete with expectant management. TVS is considered the gold standard in the diagnosis and management of incomplete miscarriage. Expectant management of miscarriage, using ultrasound parameters to determine eligibility, could significantly reduce the number of unnecessary evacuations of the retained products of conception, depending on the criteria used.