Rationalizing the follow-up of pregnancies of unknown location

Conventional and modern markers of pregnancy of unknown location: Update and narrative review

Pregnancy of unknown location (PUL) is a temporary pathologic or physiologic phenomenon of early pregnancy that requires follow up to determine the final pregnancy outcome. Evidence indicated that PUL patients suffer a remarkably higher rate of adverse pregnancy outcomes, represented by ectopic gestation and early pregnancy loss, than the general population. In the past few decades, discussion about PUL has never stopped, and a variety of markers have been widely investigated for the early and accurate evaluation of PUL, including serum biomarkers, ultrasound imaging features, multivariate analysis, and the diagnosis of ectopic pregnancy based on risk stratification. So far, machine learning (ML) methods represented by M4 and M6 logistic regression have gained a level of recognition and are continually improving. Nevertheless, the heterogeneity of PUL markers, mainly caused by the limited sample size, the differences in population and technical maturity, etc., have hampered the management of PUL. With the advancement of multidisciplinary integration and cutting-edge technologies (e.g. artificial intelligence, prediction model development, and telemedicine), novel markers, and strategies for the management of PUL are expected to be developed. In this review, we summarize both conventional and novel markers (represented by artificial intelligence) for PUL assessment and management, investigate their advancements, limitations and challenges, and propose insights on future research direction and clinical application.

Comparison of single- and double-dose methotrexate protocols for treatment of pregnancy of unknown location

OBJECTIVE

The use of various methotrexate (MTX) protocols for the treatment of ectopic pregnancy is well established. This study aimed to evaluate the efficacy of single- and double-dose MTX protocols for the treatment of pregnancy of unknown location (PUL).

STUDY DESIGN

This retrospective study was conducted in the Department of Gynaecological Endocrinology, University Hospital, Krakow, Poland. Haemodynamically stable women with PUL were enrolled between January 2014 and September 2023. Demographics, gestational age and treatment outcomes were compared between women in the single-dose MTX group and women in the double-dose MTX group. The primary outcome was the success rate, measured as the number of women treated without surgical intervention. The secondary outcome was the number of days of MTX needed to achieve an appropriate decrease in beta-human chorionic gonadotrophin (β-hCG).

RESULTS

Two hundred and eleven women (mean age 33 ± 1.8 years) with PUL were enrolled in the study, with an overall success rate of 89.1 %. Single- and double-dose MTX protocols were found to have comparable treatment success rates (93 % and 95 %, respectively). Women with lower initial serum β-hCG (<2000 mIU/ml) had higher treatment efficacy compared with women with higher initial serum β-hCG (96.5 % vs 71.4 %), regardless of protocol type. The length of hospital stay for the women treated with the single-dose MTX protocol was 1 day shorter compared with that for the women treated with the double-dose MTX protocol.

CONCLUSION

Single- and double-dose MTX protocols have comparable efficacy and safety, and should be equally considered in women with PUL with initial β-hCG < 2000 mIU/ml.

β-Human Chorionic Gonadotropin Dynamics in Early Gestational Events: A Practical and Updated Reappraisal

In the last decade, the widespread use of transvaginal ultrasound and the availability of highly specific serum assays of human chorionic gonadotropin (hCG) have become mainstays in the evaluation of early pregnancy. These tests have revolutionized the management of pregnancies of unknown location and markedly reduced the morbidity and mortality associated with the misdiagnosis of ectopic pregnancy. However, despite several advances, their misuse and misinterpretations are still common, leading to an increased use of healthcare resources, patient misinformation, and anxiety. This narrative review aims to succinctly summarize the β-hCG dynamics in early gestation and provide general gynecologists a practical approach to patients with first-trimester symptomatic pregnancy.

Updating M6 pregnancy of unknown location risk-prediction model including evaluation of clinical factors

OBJECTIVES

Ectopic pregnancy (EP) is a major high-risk outcome following a pregnancy of unknown location (PUL) classification. Biochemical markers are used to triage PUL as high vs low risk to guide appropriate follow-up. The M6 model is currently the best risk-prediction model. We aimed to update the M6 model and evaluate whether performance can be improved by including clinical factors.

METHODS

This prospective cohort study recruited consecutive PUL between January 2015 and January 2017 at eight units (Phase 1), with two centers continuing recruitment between January 2017 and March 2021 (Phase 2). Serum samples were collected routinely and sent for β-human chorionic gonadotropin (β-hCG) and progesterone measurement. Clinical factors recorded were maternal age, pain score, bleeding score and history of EP. Based on transvaginal ultrasonography and/or biochemical confirmation during follow-up, PUL were classified subsequently as failed PUL (FPUL), intrauterine pregnancy (IUP) or EP (including persistent PUL (PPUL)). The M6 models with (M6P ) and without (M6NP ) progesterone were refitted and extended with clinical factors. Model validation was performed using internal-external cross-validation (IECV) (Phase 1) and temporal external validation (EV) (Phase 2). Missing values were handled using multiple imputation.

RESULTS

Overall, 5473 PUL were recruited over both phases. A total of 709 PUL were excluded because maternal age was < 16 years or initial β-hCG was ≤ 25 IU/L, leaving 4764 (87%) PUL for analysis (2894 in Phase 1 and 1870 in Phase 2). For the refitted M6P model, the area under the receiver-operating-characteristics curve (AUC) for EP/PPUL vs IUP/FPUL was 0.89 for IECV and 0.84-0.88 for EV, with respective sensitivities of 94% and 92-93%. For the refitted M6NP model, the AUCs were 0.85 for IECV and 0.82-0.86 for EV, with respective sensitivities of 92% and 93-94%. Calibration performance was good overall, but with heterogeneity between centers. Net Benefit confirmed clinical utility. The change in AUC when M6P was extended to include maternal age, bleeding score and history of EP was between -0.02 and 0.01, depending on center and phase. The corresponding change in AUC when M6NP was extended was between -0.01 and 0.03. At the 5% threshold to define high risk of EP/PPUL, extending M6P altered sensitivity by -0.02 to -0.01, specificity by 0.03 to 0.04 and Net Benefit by -0.005 to 0.006. Extending M6NP altered sensitivity by -0.03 to -0.01, specificity by 0.05 to 0.07 and Net Benefit by -0.005 to 0.006.

CONCLUSIONS

The updated M6 model offers accurate diagnostic performance, with excellent sensitivity for EP. Adding clinical factors to the model improved performance in some centers, especially when progesterone levels were not suitable or unavailable. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Methotrexate vs expectant management for treatment of tubal ectopic pregnancy: An individual participant data meta-analysis

INTRODUCTION

Ectopic pregnancy is an important health condition which affects up to 1 in 100 women. Women who present with mild symptoms and low serum human chorionic gonadotrophin (hCG) are often treated with methotrexate (MTX), but expectant management with close monitoring is a feasible alternative. Studies comparing the two treatments have not shown a statistically significant difference in uneventful resolution of ectopic pregnancy, but these studies were too small to define whether certain subgroups could benefit more from either treatment.

MATERIAL AND METHODS

We performed a systematic review and individual participant data meta-analysis (IPD-MA) of randomized controlled trials comparing systemic MTX and expectant management in women with tubal ectopic pregnancy and low hCG (<2000 IU/L). A one-stage IPD-MA was performed to assess overall treatment effects of MTX and expectant management to generate a pooled intervention effect. Subgroup analyses and exploratory multivariable analyses were undertaken according to baseline serum hCG and progesterone levels. Primary outcome was treatment success, defined as resolution of clinical symptoms and decline in level of serum hCG to <20 IU/L, or a negative urine pregnancy test by the initial intervention strategy, without any additional treatment. Secondary outcomes were need for blood transfusion, surgical intervention, additional MTX side-effects and hCG resolution times.

TRIAL REGISTRATION NUMBER

PROSPERO: CRD42021214093.

RESULTS

1547 studies reviewed and 821 remained after duplicates removed. Five studies screened for eligibility and three IPD requested. Two randomized controlled trials supplied IPD, leading to 153 participants for analysis. Treatment success rate was 65/82 (79.3%) after MTX and 48/70 (68.6%) after expectant management (IPD risk ratio [RR] 1.16, 95% confidence interval [CI] 0.95-1.40). Surgical intervention rates were not significantly different: 8/82 (9.8%) vs 13/70 (18.6%) (RR 0.65, 95% CI 0.23-1.14). Mean time to success was 19.7 days (95% CI 17.4-22.3) after MTX and 21.2 days (95% CI 17.8-25.2) after expectant management (P = 0.25). MTX specific side-effects were reported in 33 MTX compared to four in the expectant group.

CONCLUSIONS

Our IPD-MA showed no statistically significant difference in treatment efficacy between MTX and expectant management in women with tubal ectopic pregnancy with low hCG. Initial expectant management could be the preferred strategy due to fewer side-effects.

Diagnostic value of a urine test in pregnancy of unknown location

BACKGRO

Pregnancy of unknown location (PUL) is a term used when there is a positive pregnancy test but no sonographic evidence for an intrauterine pregnancy (IUP) or ectopic pregnancy (EP). This term is a classification and not a final diagnosis.

OBJECTIVE

This study aimed to evaluate the diagnostic value of the Inexscreen test on the outcome of patients with pregnancies of unknown location.

STUDY DESIGN

In this prospective study, a total of 251 patients with a diagnosis of pregnancy of unknown location at the gynecologic emergency department of the La Conception Hospital, Marseille, France, between June 2015 and February 2019 were included. The Inexscreen (semiquantitative determination of intact human urinary chorionic gonadotropin) test was performed on patients with a diagnosis of pregnancy of unknown location. They participated in the study after information and consent collection. The main outcome measures (sensitivity, specificity, predictive values, and the Youden index) of Inexscreen were calculated for the diagnosis of abnormal pregnancy (nonprogressive pregnancy) and ectopic pregnancy.

RESULTS

The sensitivity and specificity of Inexscreen for the diagnosis of abnormal pregnancy in patients with pregnancy of unknown location were 56.3% (95% confidence interval, 47.0%-65.1%) and 62.8% (95% confidence interval, 53.1%-71.5%), respectively. The sensitivity and specificity of Inexscreen for the diagnosis of ectopic pregnancy in patients with pregnancy of unknown location were 81.3% (95% confidence interval, 57.0%-93.4%) and 55.6% (95% confidence interval, 48.6%-62.3%), respectively. The positive predictive value and negative predictive value of Inexscreen for ectopic pregnancy were 12.9% (95% confidence interval, 7.7%-20.8%) and 97.4% (95% confidence interval, 92.5%-99.1%), respectively.

CONCLUSION

Inexscreen is a rapid, non-operator-dependent, noninvasive, and inexpensive test that allows the selection of patients at high risk of ectopic pregnancy in case of pregnancy of unknown location. This test allows an adapted follow-up according to the technical platform available in a gynecologic emergency service.

Predictive Analytic Model for Diagnosis of Ectopic Pregnancy

Objective: Ectopic pregnancy (EP) is a serious condition. Delayed diagnosis could lead to life-threatening outcomes. The study aimed to develop a diagnostic predictive model for EP to approach suspected cases with prompt intervention before the rupture occurred. Methods: A retrospective cross-sectional study enrolled 347 pregnant women presenting first-trimester complications (abdominal pain or vaginal bleeding) with diagnosis suspected of pregnancy of unknown location, who were eligible and underwent chart review. The data including clinical risk factors, signs and symptoms, serum human chorionic gonadotropin (hCG), and ultrasound findings were analyzed. The statistical predictive score was developed by performing logistic regression analysis. The testing data of 30 patients were performed to test the validation of predictive scoring. Results: From a total of 22 factors, logistic regression method-derived scoring model was based on five potent factors (history of pelvic inflammatory disease, current use of emergency pills, cervical motion tenderness, serum hCG ≥1,000 mIU/ml, and ultrasound finding of adnexal mass) using a cutoff score ≥3. This predictive index score was able to determine ectopic pregnancy with an accuracy of 77.8% [95% confidence interval (CI) = 73.1-82.1], specificity of 91.0% (95% CI = 62.1-72.0), sensitivity of 67.0% (95% CI = 88.0-94.0), and area under the curve of 0.906 (95% CI = 0.875-0.937). In the validation group, no patient with negative result of this score had an EP. Conclusion: Statistical predictive score was derived with high accuracy and applicable performance for EP diagnosis. This score could be used to support clinical decision making in routine practice for management of EP.

Triaging women with pregnancy of unknown location using two-step protocol including M6 model: clinical implementation study

OBJECTIVE

The M6 risk-prediction model was published as part of a two-step protocol using an initial progesterone level of ≤ 2 nmol/L to identify probable failing pregnancies (Step 1) followed by the M6 model (Step 2). The M6 model has been shown to have good triage performance for stratifying women with a pregnancy of unknown location (PUL) as being at low or high risk of harboring an ectopic pregnancy (EP). This study validated the triage performance of the two-step protocol in clinical practice by evaluating the number of protocol-related adverse events and how effectively patients were triaged.

METHODS

This was a prospective multicenter interventional study of 3272 women with a PUL, carried out between January 2015 and January 2017 in four district general hospitals and four university teaching hospitals in the UK. The final pregnancy outcome was defined as: a failed PUL (FPUL), an intrauterine pregnancy (IUP) or an EP (including persistent PUL (PPUL)). FPUL and IUP were grouped as low-risk and EP/PPUL as high-risk PUL. Serum progesterone and human chorionic gonadotropin (hCG) levels were measured at presentation in all patients. If the initial progesterone level was ≤ 2 nmol/L, patients were discharged and were asked to have a follow-up urine pregnancy test in 2 weeks to confirm a negative result. If the progesterone level was > 2 nmol/L or a measurement had not been taken, hCG level was measured again at 48 h and results were entered into the M6 model. Patients were managed according to the outcome predicted by the protocol. Those classified as 'low risk, probable FPUL' were advised to perform a urine pregnancy test in 2 weeks and those classified as 'low risk, probable IUP' were invited for a scan a week later. When a woman with a PUL was classified as high risk (i.e. risk of EP ≥ 5%) she was reviewed clinically within 48 h. One center used a progesterone cut-off of ≤ 10 nmol/L and its data were analyzed separately. If the recommended management protocol was not adhered to, this was recorded as a protocol deviation and classified as: unscheduled visit for clinician reason, unscheduled visit for patient reason or incorrect timing of blood test or ultrasound scan. The classifications outlined in the UK Good Clinical Practice (GCP) guidelines were used to evaluate the incidence of adverse events. Data were analyzed using descriptive statistics.

RESULTS

Of the 3272 women with a PUL, 2625 were included in the final analysis (317 met the exclusion criteria or were lost to follow-up, while 330 were evaluated using a progesterone cut-off of ≤ 10 nmol/L). Initial progesterone results were available for 2392 (91.1%) patients. In Step 1, 407 (15.5%) patients were classified as low risk (progesterone ≤ 2 nmol/L), of whom seven (1.7%) were ultimately diagnosed with an EP. In 279 of the remaining 2218 women with a PUL, the M6 model was not applied owing to protocol deviation or because the outcome was already known (usually on the basis of an ultrasound scan) before a second hCG reading was taken; of these patients, 30 were diagnosed with an EP. In Step 2, 1038 women with a PUL were classified as low risk, of whom eight (0.8%) had a final outcome of EP. Of 901 women classified as high risk at Step 2, 275 (30.5%) had an EP. Therefore, 275/320 (85.9%) EPs were correctly classified as high risk. Overall, 1445/2625 PUL (55.0%) were classified as low risk, of which 15 (1.0%) were EP. None of these cases resulted in a ruptured EP or significant clinical harm. Sixty-two women participating in the study had an adverse event, but no woman had a serious adverse event as defined in the UK GCP guidelines.

CONCLUSIONS

This study has shown that the two-step protocol incorporating the M6 model effectively triaged the majority of women with a PUL as being at low risk of an EP, minimizing the follow-up required for these patients after just two visits. There were few misclassified EPs and none of these women came to significant clinical harm or suffered a serious adverse clinical event. The two-step protocol incorporating the M6 model is an effective and clinically safe way of rationalizing the management of women with a PUL. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

Pregnancy of unknown location

Pregnancy of unknown location is a situation in which a positive pregnancy test occurs, but a transvaginal ultrasound does not show intrauterine or ectopic gestation. One great concern of pregnancy of unknown location is that they are cases of ectopic pregnancy whose diagnosis might be postponed. Transvaginal ultrasound is able to identify an ectopic pregnancy with a sensitivity ranging from 87% to 94% and a specificity ranging from 94% to 99%. A patient with pregnancy of unknown location should be followed up until an outcome is obtained. The only valid biomarkers with clinical application and validation are serum levels of the beta fraction of hCG and progesterone. A single serum dosage of hCG is used only to determine whether the value obtained is above or below the discriminatory zone, that means the value of serum hCG above which an intrauterine gestational sac should be visible on ultrasound. Serum progesterone levels are a satisfactory marker of pregnancy viability, but they are unable to predict the location of a pregnancy of unknown location: levels below 5 ng/mL are associated with nonviable gestations, whereas levels above 20 ng/mL are correlated with viable intrauterine pregnancies. Most cases are low risk and can be monitored by expectant management with transvaginal ultrasound and serial serum hCG levels, in addition to the serum progesterone levels. To minimize diagnostic error and intervene during progressive intrauterine gestation, protocol indicates active treatment only in situations when progressive intrauterine pregnancy is excluded and a high possibility of ectopic pregnancy exists.

Diagnostic protocols for the management of pregnancy of unknown location: a systematic review and meta-analysis

BACKGROUND

There is no international consensus on how to manage women with a pregnancy of unknown location (PUL).

OBJECTIVES

To present a systematic quantitative review summarising the evidence related to management protocols for PUL.

SEARCH STRATEGY

MEDLINE, COCHRANE and DARE databases were searched from 1 January 1984 to 31 January 2017. The primary outcome was accurate risk prediction of women initially diagnosed with a PUL having an ectopic pregnancy (high risk) as opposed to either a failed PUL or intrauterine pregnancy (low risk).

SELECTION CRITERIA

All studies written in the English language, which were not case reports or series that assessed women classified as having a PUL at initial ultrasound.

DATA COLLECTION AND ANALYSIS

Forty-three studies were included. QUADAS-2 criteria were used to assess the risk of bias. We used a novel, linear mixed-effects model and constructed summary receiver operating characteristic curves for the thresholds of interest.

MAIN RESULTS

There was a high risk of differential verification bias in most studies. Meta-analyses of accuracy were performed on (i) single human chorionic gonadotrophin (hCG) cut-off levels, (ii) hCG ratio (hCG at 48 hours/initial hCG), (iii) single progesterone cut-off levels and (iv) the 'M4 model' (a logistic regression model based on the initial hCG and hCG ratio). For predicting an ectopic pregnancy, the areas under the curves (95% CI) for these four management protocols were as follows: (i) 0.42 (0.00-0.99), (ii) 0.69 (0.57-0.78), (iii) 0.69 (0.54-0.81) and (iv) 0.87 (0.83-0.91), respectively.

CONCLUSIONS

The M4 model was the best available method for predicting a final outcome of ectopic pregnancy. Developing and validating risk prediction models may optimise the management of PUL.

TWEETABLE ABSTRACT

Pregnancy of unknown location meta-analysis: M4 model has best test performance to predict ectopic pregnancy.

Endometriosis and Beta-hCG > 775 IU/l Increase the Risk of Non-tube-preserving Surgery for Tubal Pregnancy

Introduction

Tubal pregnancy is the most clinically relevant form of ectopic pregnancy. Surgery consisting of laparoscopic salpingotomy is the therapeutic gold standard. This study looked at risk factors for non-tube-preserving surgery. The aim was to determine a cut-off value for beta-hCG levels, which could be used to predict the extent of tubal surgery.

Materials and Method

97 patients with tubal pregnancy who underwent primary salpingotomy in the Department of Gynecology and Obstetrics of Jena University Hospital between 2010 and 2016 were retrospectively analyzed. A prior medical history of risk factors such as adnexitis, ectopic pregnancy, tubal surgery, treatment for infertility and intrauterine pessary was included in the analysis. The study population was divided into two subgroups: (1) a group which underwent laparoscopic linear salpingotomy, and (2) a group which had laparoscopic partial tubal resection or salpingectomy. Risk factors for salpingectomy were determined using binary logistic regression analysis. Statistical analysis was done using SPSS, version 24.0, to identify risk factors for non-tube-preserving surgery.

Results

68 patients (70.1%) underwent laparoscopic salpingotomy and 29 patients (29.9%) had laparoscopic salpingectomy. The two groups differed with regard to age (p = 0.01) but not with regard to the parameters ‘gestational age’, ‘viability and rupture status of the ectopic pregnancy’ or ‘symptoms at presentation’. Patients who were known to have endometriosis prior to surgery or who were diagnosed with endometriosis intraoperatively were more likely to undergo salpingectomy (OR: 3.28; 95% CI: 0.9 – 10.8; p = 0.05). Calculated mean beta-hCG levels were higher in the salpingectomy group compared to the group who had tube-preserving salpingotomy (3277.8 IU/l vs. 9338.3 IU/l, p = 0.01). A cut-off beta-hCG value of 775 IU/l prior to surgery was predictive for salpingectomy with a true positive rate of 86.2% and increased the probability that salpingectomy would be necessary (OR: 5.23; 95% CI: 0.229 – 0.471; p = 0.005).

Conclusion

Endometriosis and a beta-hCG value of more than 775 IU/l significantly increased the risk for non-tube-preserving surgery in women with tubal pregnancy.

The potential value of activin B and fibronectin for the triage of pregnancies of unknown location and prediction of first trimester viability

Aim

We have assessed the potential predictive ability of the biomarkers activin B and fibronectin (FN1) alone and when added to established markers for triaging patients as being at low or high risk of ectopic pregnancy (EP). We also assessed their use as predictors of viability at 12 weeks gestation.

Methods

Exploratory secondary analysis of a prospective study including all women classified as a pregnancy of known location (PUL) based on transvaginal ultrasonography between January and December 2007 at the early pregnancy unit of St Georges' Hospital (London). We used multinomial logistic regression to assess the diagnostic potential of the biomarkers to triage PUL at high risk of complications (EP or persistent PUL), and standard binary logistic regression to predict first trimester viability at 12 weeks.

Results

For discriminating high-risk (n = 16) from low-risk PUL (n = 93), the area under the receiver operating characteristic curve (AUC) was 0.75 (95% confidence interval 0.60-0.85) for activin B and 0.55 (0.41-0.68) for FN1. Adding activin B to a multinomial logistic regression model incorporating β-hCG ratio and initial progesterone yielded odds ratios of 0.16 (0.05-0.55) for failing vs high-risk PUL and 0.29 (0.07-1.19) for intrauterine vs high-risk PUL and increased the model's AUC from 0.84 to 0.89. At a risk threshold of 5% for high-risk PUL, sensitivity increased from 84% to 87% and specificity from 48% to 64%. For discriminating viable (n = 28) from non-viable (n = 81) pregnancies at 12 weeks, both markers had an AUC of 0.54.

Conclusions

Our results suggested that activin B may be a promising marker to improve PUL triage in addition to established markers.

Factors to consider in pregnancy of unknown location

The management of women with a pregnancy of unknown location (PUL) can vary significantly and often lacks a clear evidence base. Intensive follow-up is usually required for women with a final outcome of an ectopic pregnancy. This, however, only accounts for a small proportion of women with a pregnancy of unknown PUL location. There remains a clear clinical need to rationalize the follow-up of PUL so women at high risk of having a final outcome of an ectopic pregnancy are followed up more intensively and those PUL at low risk of having an ectopic pregnancy have their follow-up streamlined. This review covers the main management strategies published in the current literature and aims to give clinicians an overview of the most up-to-date evidence that they can take away into their everyday clinical practice when caring for women with a PUL.

The Diagnosis and Treatment of Ectopic Pregnancy

BACKGROUND

Extrauterine pregnancy is a complication of the first trimester of pregnancy that arises in 1.3-2.4% of all pregnancies.

METHODS

This review is based on articles and guidelines retrieved by a selective PubMed search.

RESULTS

The presentation of extrauterine pregnancy is highly variable, ranging from an asymptomatic state, to pelvic pain that is worse on one side, to tubal rupture with hemorrhagic shock. 75% of tubal pre gnancies can be detected by transvaginal ultrasonography. In patients with a vital extrauterine pregnancy, the human chorionic gonadotropin concentration generally doubles within 48 hours. Laparoscopy is the gold standard of treatment. Two randomized, controlled trials comparing organ-preserving treatment with ablative surgery revealed no significant difference in pregnancy rates after the intervention, but precise details of the surgical procedures were not provided, and long-term fertility data are lacking. Metho - trexate therapy should be used only for strict indications.

CONCLUSION

Further randomized, controlled trials with longer follow-up will be needed to answer currently open questions about the potential for individualized surgical treatment and the proper role of pharmacotherapy.

Managing pregnancy of unknown location based on initial serum progesterone and serial serum hCG levels: development and validation of a two-step triage protocol

OBJECTIVES

A uniform rationalized management protocol for pregnancies of unknown location (PUL) is lacking. We developed a two-step triage protocol to select PUL at high risk of ectopic pregnancy (EP), based on serum progesterone level at presentation (step 1) and the serum human chorionic gonadotropin (hCG) ratio, defined as the ratio of hCG at 48 h to hCG at presentation (step 2).

METHODS

This was a cohort study of 2753 PUL (301 EP), involving a secondary analysis of prospectively and consecutively collected PUL data from two London-based university teaching hospitals. Using a chronological split we used 1449 PUL for development and 1304 for validation. We aimed to assign PUL as low risk with high confidence (high negative predictive value (NPV)) while classifying most EP as high risk (high sensitivity). The first triage step assigned PUL as low risk using a threshold of serum progesterone at presentation. The remaining PUL were triaged using a novel logistic regression risk model based on hCG ratio and initial serum progesterone (second step), defining low risk as an estimated EP risk of < 5%.

RESULTS

On validation, initial serum progesterone ≤ 2 nmol/L (step 1) classified 16.1% PUL as low risk. Second-step classification with the risk model selected an additional 46.0% of all PUL as low risk. Overall, the two-step protocol classified 62.1% of PUL as low risk, with an NPV of 98.6% and a sensitivity of 92.0%. When the risk model was used in isolation (i.e. without the first step), 60.5% of PUL were classified as low risk with 99.1% NPV and 94.9% sensitivity.

CONCLUSION

PUL can be classified efficiently into being either high or low risk for complications using a two-step protocol involving initial progesterone and hCG levels and the hCG ratio. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Is there a difference in the behaviour and subsequent management of ectopic pregnancies seen at first scan compared to those ectopic pregnancies which commence as pregnancies of unknown location?

AIMS

The primary aim was to assess whether ectopic pregnancies (EPs) visualised on primary scan behave differently to EPs initially characterised as pregnancies of unknown location (PUL). The secondary aim was to assess whether the EP group is more likely to have surgical management compared to the PUL ectopic pregnancy group.

MATERIALS AND METHODS

Prospective observational study. Consecutive first trimester women presenting from November 2006 to March 2012 underwent transvaginal ultrasound (TVS). Women diagnosed with an EP on TVS were divided into two groups: visualised EPs noted on the first TVS, and PULs which subsequently developed into EPs. Twenty-five historical, clinical, biochemical and ultrasonographic variables were collected. Different management strategies (expectant, medical, surgical) once an EP was confirmed on TVS were recorded. Univariate analysis was performed to compare differences between the two groups as well as rates for the three final management strategies.

RESULTS

A total of 3341 consecutive women underwent TVS. On initial scan, 86.2% were classified as intrauterine pregnancy, 8.8% as PUL and 5.0% as EP (145 tubal/23 nontubal EPs). There were 194 tubal EPs in final analysis: 49 of 194 (25.3%) initially classified as PUL and 145 of 194 (74.7%) diagnosed as EP at primary TVS. When comparing the EP to the PUL EP group, the pain scores were 3.34 versus 1.91 (P-value < 0.001), the mean sac diameters were 35.2 versus 18.5 mm (P-value = 0.0327), and the volume of the EP masses were 8.21E+04 versus 1.40E+04 (P-value = 0.0341). Cumulative surgical intervention rate was significantly higher in EP compared to PUL EP group (P-value = 0.036).

CONCLUSIONS

EPs seen at the first ultrasound scan appear to be more symptomatic, larger in diameter and volume compared to EPs which started as PULs. Cumulative surgical intervention rate was noted to be higher in this group with EP seen on ultrasound at the outset.

[Indications for methotrexate in gynecology outside the first-line treatment of ectopic tubal pregnancies]

The objective of this work is to discuss the indications for methotrexate in gynecology outside the first-line treatment of tubal ectopic pregnancy. In tubal ectopic pregnancy, the prophylactic use of systemic methotrexate can be discussed when performing laparoscopic salpingotomy. In case of failure of salpingotomy, administration seems justified especially if it avoids re-intervention. The combination of methotrexate with other therapies such as mifepristone, potassium chloride or gefitinib is not recommended in the treatment of ectopic pregnancy. For non-tubal ectopic pregnancy, the intramuscular or local administration of methotrexate is an acceptable treatment for uncomplicated interstitial pregnancies. For uncomplicated cervical or cesarean scar pregnancies, the local administration of methotrexate should be considered as a first-line treatment. For ovarian pregnancies, methotrexate should not be a first-line treatment, surgical treatment remains the standard. Asymptomatic women presenting with a pregnancy of unknown location and plateauing serum hCG concentration<2000 UI/L can be managed expectantly: it is recommended to take an additional quantitative hCG serum level after 48 hours. Thus, methotrexate is not recommended in the first intention. Other gynecological indications were discussed: methotrexate is not recommended in the management of first-trimester miscarriages or in the management of placenta accreta.

Ultrasound imaging in the management of bleeding and pain in early pregnancy

Bleeding and pain are experienced by 20% of women during the first trimester of pregnancy. Although most pregnancies complicated by pain and bleeding tend to progress normally, these symptoms are distressing for woman, and they are also associated with an increased risk of miscarriage and ectopic pregnancy. Ultrasound is the first and often the only diagnostic modality that is used to determine location of early pregnancy and to assess its health. Ultrasound is an accurate, safe, painless and relatively inexpensive diagnostic tool, which all contributed to its widespread use in early pregnancy. Pain and bleeding in early pregnancy are sometimes caused by concomitant gynaecological, gastrointestinal, and urological problems, which could also be detected on ultrasound scan. In women with suspected intra-abdominal bleeding, ultrasound scan can be used to detect the presence of blood and provide information about the extent of bleeding. In this chapter, we comprehensively review the use of ultrasound in the diagnosis and management of early pregnancy complications. We include information about the diagnosis of gynaecological and other pelvic abnormalities, which could cause pain or bleeding in pregnancy. We also provide a summary of the current views on the safety of ultrasound in early pregnancy.

The term "pregnancy of unknown location" is here to stay

The term "pregnancy of unknown location" is an ultrasound classification and not a final diagnosis. The use of this terminology is here to stay and should continue as long as there is an appreciation for what it really means. It is the responsibility of the clinician, who follows up these women with a PUL, to ensure that a final diagnosis is achieved while preserving the well-being of these women.

Pregnancy of unknown location: a consensus statement of nomenclature, definitions, and outcome

OBJECTIVE

To improve the interpretation of future studies in women who are initially diagnosed with a pregnancy of unknown location (PUL), we propose a consensus statement with definitions of population, target disease, and final outcome.

DESIGN

A review of literature and a series of collaborative international meetings were used to develop a consensus for definitions and final outcomes of women initially diagnosed with a PUL.

RESULT(S)

Global differences were noted in populations studied and in the definitions of outcomes. We propose to define initial ultrasound classification of findings into five categories: definite ectopic pregnancy (EP), probable EP, PUL, probable intrauterine pregnancy (IUP), and definite IUP. Patients with a PUL should be followed and final outcomes should be categorized as visualized EP, visualized IUP, spontaneously resolved PUL, and persisting PUL. Those with the transient condition of a persisting PUL should ultimately be classified as nonvisualized EP, treated persistent PUL, resolved persistent PUL, or histologic IUP. These specific categories can be used to characterize the natural history or location (intrauterine vs. extrauterine) of any early gestation where the initial location is unknown.

CONCLUSION(S)

Careful definition of populations and classification of outcomes should optimize objective interpretation of research, allow objective assessment of future reproductive prognosis, and hopefully lead to improved clinical care of women initially identified to have a PUL.

Does a prediction model for pregnancy of unknown location developed in the UK validate on a US population?

BACKGROUND

A logistic regression model (M4) was developed in the UK to predict the outcome for women with a pregnancy of unknown location (PUL) based on the initial two human chorionic gonadotrophin (hCG) values, 48 h apart. The purpose of this paper was to assess the utility of this model to predict the outcome for a woman (PUL) in a US population.

METHODS

Diagnostic variables included log-transformed serum hCG average of two measurements, and linear and quadratic hCG ratios. Outcomes modeled were failing PUL, intrauterine pregnancy (IUP) and ectopic pregnancy (EP). This model was applied to a US cohort of 604 women presenting with symptomatic first-trimester pregnancies, who were followed until a definitive diagnosis was made. The model was applied before and after correcting for differences in terminology and diagnostic criteria.

RESULTS

When retrospectively applied to the adjusted US population, the M4 model demonstrated lower areas under the curve compared with the UK population, 0.898 versus 0.988 for failing PUL/spontaneous miscarriage, 0.915 versus 0.981 for IUP and 0.831 versus 0.904 for EP. Whereas the model had 80% sensitivity for EP using UK data, this decreased to 49% for the US data, with similar specificities. Performance only improved slightly (55% sensitivity) when the US population was adjusted to better match the UK diagnostic criteria.

CONCLUSIONS

A logistic regression model based on two hCG values performed with modest decreases in predictive ability in a US cohort for women at risk for EP compared with the original UK population. However, the sensitivity for EP was too low for the model to be used in clinical practice in its present form. Our data illustrate the difficulties of applying algorithms from one center to another, where the definitions of pathology may differ.

Use of serum progesterone measurements to reduce need for follow-up in women with pregnancies of unknown location

OBJECTIVE

To assess the efficacy of a progesterone-based algorithm for the management of women with pregnancies of unknown location (PULs) and explore the feasibility of developing a single-visit strategy in those with a low risk of requiring medical intervention.

METHODS

All clinically stable women in whom pregnancy could not be identified on ultrasound scan were managed by a pre-defined protocol based on measurement of serum progesterone and beta-human chorionic gonadotropin (beta-hCG). Intervention in the form of surgery or medical treatment with methotrexate was offered to all women with persistent or worsening symptoms and non-declining serum beta-hCG. Decision-tree analysis was used to develop a protocol for the management of women with resolving pregnancies who are at low risk of requiring medical intervention.

RESULTS

1110 women were included in the data analysis: normal intrauterine pregnancy was diagnosed in 248 (22.3%; 95% CI, 19.9-24.8) women. 761 (68.6%; 95% CI, 65.8-71.3) abnormal pregnancies resolved spontaneously on expectant management, while the remaining 101 (9.1%; 95% CI, 7.4-10.8) women with abnormal pregnancies required some form of medical intervention. Intervention rates in patients presenting with initial serum progesterone levels of <or= 20 nmol/L and <or= 10 nmol/L, were 3.9% (95% CI, 2.4-5.4) and 2.1% (95% CI, 0.9-3.3), respectively. In women presenting with progesterone <or= 10 nmol/L and beta-hCG < 450 IU/L, the intervention rate was 1.3% (95% CI, 0.2-2.5).

CONCLUSION

Women with PULs with progesterone <or= 10 nmol/L at presentation are at low risk of requiring medical intervention and may not benefit from attending routine follow-up visits.

Diagnosis of ectopic pregnancy with ultrasound

Transvaginal sonography (TVS) is now the imaging modality of choice for the diagnosis of ectopic pregnancy with overall reported sensitivities of>90%. Specific sonographic criteria exist for the diagnosis of tubal and non-tubal pregnancies including cervical and caesarean section scar pregnancies. Diagnosis is based on the visualization of an ectopic mass rather than the inability to visualize an intra-uterine pregnancy. This chapter discusses the specific criteria used for the diagnosis of ectopic pregnancy and examines the literature assessing the accuracy of ultrasound as a diagnostic tool.

Predicting Outcomes in Pregnancies of Unknown Location

A pregnancy of unknown location (PUL) is a descriptive term used to classify a woman when she has a positive pregnancy test but no intra- or extra-uterine pregnancy is visualized on transvaginal sonography. Expectant management has been shown to be safe for the majority of women with a PUL. Serum progesterone and human chorionic gonadotrophin levels as well as mathematical models play a role in predicting the final outcomes of PULs, which include intrauterine pregnancy, failing PUL and ectopic pregnancy. Other possible predictors of outcome have been studied, but currently no factor has been identified that combines accuracy with reproducibility and simplicity. This article discusses the various aspects of the management of women with PULs. Future work should be aimed at prospectively testing current models in order to predict the outcome of a PUL and minimizing follow-up.