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.

Evaluation of treatments for Bartholin's cyst or abscess: a systematic review

BACKGROUND

No consensus on the management of symptomatic cysts or abscesses of the Bartholin's gland exists.

OBJECTIVES

To assess the effectiveness and safety of surgical interventions for a symptomatic Bartholin's cyst or abscess.

SEARCH STRATEGY

We searched bibliographical databases from inception to April 2019.

SELECTION CRITERIA

Randomised trials evaluating a surgical intervention for the treatment of a symptomatic Bartholin's cyst or abscess.

DATA COLLECTION AND ANALYSIS

Eight trials, reporting data from 699 women, were included. Study characteristics and methodological quality were recorded for each trial. Summary estimates were calculated using random-effects methods.

MAIN RESULTS

When considering the recurrence of a symptomatic Bartholin's cyst or abscess, the evidence was consistent with notable effects in either direction (risk ratio [RR] 0.76; 95% confidence interval [CI] 0.41-1.40) when comparing marsupialisation with incision, drainage and insertion of a Word catheter. Limited inference could be made when comparing marsupialisation with incision, drainage and silver nitrate insertion (RR 1.00; 95% CI 0.57-1.75), and incision, drainage and cavity closure (RR 0.25; 95% CI 0.01-4.89). There was limited reporting of secondary outcomes, including haematoma, infectious morbidity and persistent dyspareunia.

CONCLUSIONS

Current randomised trial evidence does not support the use of any single surgical intervention for the treatment of a symptomatic cyst or abscess of the Bartholin's gland.

PROSPECTIVE REGISTRATION

PROSPERO: International Prospective Register of Systematic Reviews; CRD42018088553.

TWEETABLE ABSTRACT

Further research is needed to identify an effective treatment for #Bartholin's cyst or abscess. @jamesmnduffy.

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.

Contingency Training Alters Neurobiological Components of Emotional Resilience in Male and Female Rats

Prior research with a rat model of behavioral therapy [i.e., effort-based reward (EBR) contingency training] suggests that strengthened associations between physical effort and desired outcomes enhance neurobiological indices of resilience. In the current study, male and female Long-Evans rats were exposed to either six weeks of EBR training or noncontingent training prior to 10 days of exposure to chronic unpredictable stress (CUS). Subsequently, all animals were exposed to a problem-solving task and then trained in a spatial learning/foraging task, the Dry Land Maze (DLM). Following habituation training and test trials, rats were assessed in a probe trial that generated a prediction error (cognitive uncertainty). Results indicated that, during CUS exposure, contingency-training enhanced dehydroepiandrosterone/corticosterone ratios (consistent with healthier stress responses), especially in male rats. Additionally, contingency training increased exploratory behaviors in the probe trial as well as differentially influenced on-task problem-solving performance in males and females. Following the probe trial, brains were exposed to histological analyses to determine the effects of sex and contingency training on various neurobiological markers. Contingency training decreased BDNF-immunoreactivity (ir) in the hippocampus CA1 and lateral habenula, implicating differential neuroplasticity responses in the training groups. Further, coordinated fos-ir activation in areas associated with emotional resilience (i.e., motivation-regulation) was observed in contingent-trained animals. In sum, the current findings confirm that behavioral training is associated with neurobiological markers of emotional resilience; however, further assessments are necessary to more accurately determine the therapeutic potential for the EBR contingency training model.

Abstract PD8-01: Race and age differences in PAM50 biomarker status in the Carolina breast cancer study

Background: African American breast cancer patients have lower relative frequency of hormone receptor (HR)-positive/HER2-negative disease and higher subtype-specific mortality. However, few population-based studies have RNA-based subtyping data, and racial differences in the biology of HR-positive/HER2-negative tumors are not well understood.

Methods: Using data and biospecimens from the Carolina Breast Cancer Study (CBCS) Phase 3 (2008-2013), we classified approximately 1,000 invasive breast cancers according to PAM50 subtype and two risk of recurrence scores (ROR-P and ROR-PT). Relative frequency of Luminal A, Luminal B, Her2-enriched, and Basal-like subtypes and ROR scores (low/medium/high) were compared by race (blacks vs. whites) and age (≤50 years vs. &gt;50 years), overall and among HR-positive/HER2-negative cases.

Results: Black women of all ages had significantly higher relative frequency of Basal-like breast cancer (36 and 31% in blacks vs. 18 and 15% in whites; younger and older, respectively) and lower frequency of Luminal A breast cancer (26 and 34% in blacks vs. 43 and 52% in whites; younger and older, respectively). Frequency of Luminal B and HER2-enriched breast cancer did not vary by race or age. Among clinically HR-positive, HER2-negative cases, Luminal A subtype comprised only half of the cases among black women, and was significantly less common than among white women (51% vs 60% in whites, p&lt;0.05). Black women with HR-positive/HER2-negative disease also had significantly higher ROR scores (ROR-P medium or high 82% vs. 66% in whites, p=0.01; ROR-PT medium or high 85% vs. 69% in whites, p&lt;0.01).

Conclusions: Multi-gene assays highlight disparities in frequency of aggressive, poorer prognosis tumor subtypes and implicate differences in tumor biology as an important contributor to mortality disparities among HR-positive/HER2-negative patients.

Citation Format: Troester MA, Sun X, Allott EH, Kit C-K, Thorne L, Mathews M, Cohen SM, Geradts J, Kirk E, Li Y, Hu Z, Robinson W, Hoadley KA, Reeder-Hayes K, Earp S, Olshan AF, Carey LA, Perou CM. Race and age differences in PAM50 biomarker status in the Carolina breast cancer study [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr PD8-01.

In situ membrane bending setup for strain-dependent scanning transmission x-ray microscopy investigations

We present a setup that allows for the in situ generation of tensile strains by bending x-ray transparent Si₃N₄ membranes with the application of a pressure difference between the two sides of the membrane, enabling the possibility to employ high resolution space- and time-resolved scanning transmission x-ray microscopy for the investigation of the magneto-elastic coupling.

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.

Nearly amorphous Mo-N gratings for ultimate resolution in extreme ultraviolet interference lithography

We present fabrication and characterization of high-resolution and nearly amorphous Mo1 - xNx transmission gratings and their use as masks for extreme ultraviolet (EUV) interference lithography. During sputter deposition of Mo, nitrogen is incorporated into the film by addition of N2 to the Ar sputter gas, leading to suppression of Mo grain growth and resulting in smooth and homogeneous thin films with a negligible grain size. The obtained Mo0.8N0.2 thin films, as determined by x-ray photoelectron spectroscopy, are characterized to be nearly amorphous using x-ray diffraction. We demonstrate a greatly reduced Mo0.8N0.2 grating line edge roughness compared with pure Mo grating structures after e-beam lithography and plasma dry etching. The amorphous Mo0.8N0.2 thin films retain, to a large extent, the benefits of Mo as a phase grating material for EUV wavelengths, providing great advantages for fabrication of highly efficient diffraction gratings with extremely low roughness. Using these grating masks, well-resolved dense lines down to 8 nm half-pitch are fabricated with EUV interference lithography.

Limitations of current definitions of miscarriage using mean gestational sac diameter and crown-rump length measurements: a multicenter observational study

OBJECTIVES

There is significant variation in cut-off values for mean gestational sac diameter (MSD) and embryo crown-rump length (CRL) used to define miscarriage, values suggested in the literature ranging from 13 to 25 mm for MSD and from 3 to 8 mm for CRL. We aimed to define the false-positive rate (FPR) for the diagnosis of miscarriage associated with different CRL and MSD measurements with or without a yolk sac in a large study population of patients attending early pregnancy clinics. We also aimed to define cut-off values for CRL and MSD that, on the basis of a single measurement, can definitively diagnose a miscarriage and so exclude possible inadvertent termination of pregnancy.

METHODS

This was an observational cross-sectional study. Data were collected prospectively according to a predefined protocol. Intrauterine pregnancy of uncertain viability (IPUV) was defined as an empty gestational sac or sac with a yolk sac but no embryo seen with MSD < 20 or < 30 mm or an embryo with an absent heartbeat and CRL < 6 mm or < 8 mm. We recruited to the study 1060 consecutive women with IPUV. The endpoint was presence or absence of a viable pregnancy at the time of first-trimester screening ultrasonography between 11 and 14 weeks. The sensitivity, specificity, positive and negative predictive values were calculated for potential cut-off values to define miscarriage from MSD 8 to 30 mm with or without a yolk sac and from CRL 3 to 8 mm.

RESULTS

Of the 1060 women with a diagnosis of IPUV, 473 remained viable and 587 were non-viable by the time of the 11-14-week scan. In the absence of both embryo and yolk sac, the FPR for miscarriage was 4.4% when an MSD cut-off of 16 mm was used and 0.5% for a cut-off of 20 mm. There were no false-positive test results for miscarriage when a cut-off of MSD ≥ 21 mm was used. If a yolk sac was present but an embryo was not, the FPR for miscarriage was 2.6% for an MSD cut-off of 16 mm and 0.4% for a cut-off of 20 mm, with no false-positive results when a cut-off of MSD ≥ 21 mm was used. When an embryo was visible with an absent heartbeat, using a CRL cut-off of 4 mm the FPR for miscarriage was 8.3%, and for a CRL cut-off of 5 mm it was also 8.3%. There were no false-positive results using a CRL cut-off of ≥ 5.3 mm.

CONCLUSIONS

These data show that some current definitions used to diagnose miscarriage are potentially unsafe. Current national guidelines should be reviewed to avoid inadvertent termination of wanted pregnancies. An MSD cut-off of > 25 mm and a CRL cut-off of > 7 mm could be introduced to minimize the risk of a false-positive diagnosis of miscarriage.

Gestational sac and embryonic growth are not useful as criteria to define miscarriage: a multicenter observational study

OBJECTIVES

We studied changes in mean gestational sac diameter (MSD) and embryonic crown-rump length (CRL) in intrauterine pregnancies of uncertain viability (IPUVs). We aimed to establish cut-off values for MSD and CRL growth that could be definitively associated with either viability or miscarriage, and to establish the relationship between growth in MSD and appearance of embryonic structures in the gestational sac.

METHODS

One thousand and sixty consecutive IPUVs were recruited prospectively from four London University hospitals: 462 with no yolk sac or embryo, 419 with a yolk sac but no embryo, and 179 with an embryo but no heartbeat visible. IPUV was defined as an empty gestational sac with or without a yolk sac but no embryo seen with MSD < 20 or < 30 mm (depending on center) or an embryo with no heartbeat and CRL < 6 mm or < 8 mm (depending on center). Scans were repeated 7-14 days later. The endpoint was viability at first-trimester screening ultrasonography between 11 and 14 weeks. Change in MSD and CRL between the first and second scans of each pregnancy was compared with respect to viability and appearance of embryonic structures using the two-sample t-test.

RESULTS

The study included 359 pregnancies in which a gestational sac with or without embryo was identified at the follow-up scan 7-14 days later. Of these, 192 were viable and 167 non-viable at the 11-14-week scan. MSD growth was significantly higher in viable than non-viable pregnancies (mean 1.003 vs. 0.503 mm/day; P < 0.001, 95% CI of difference 0.403-0.596). A difference in CRL growth was found between the two groups (mean 0.673 vs. 0.148 mm/day; P < 0.001, 95% CI of difference 0.345-0.703). MSD growth of 0.6 mm/day was associated with a specificity for diagnosing miscarriage of 90.1%, a sensitivity of 61.7% and 19 false-positive test results. A cut-off of CRL growth rate of 0.2 mm/day gave a sensitivity of 76.3% and there were no false-positive test results for miscarriage. On repeat scan the failure of either a yolk sac or embryo to be visualized was always associated with miscarriage.

CONCLUSION

There is an overlap in MSD growth rates between viable and non-viable IPUV. No cut-off exists for MSD growth below which a viable pregnancy could be safely excluded. A cut-off value for CRL growth of 0.2 mm/day was always associated with miscarriage. These data suggest that criteria to diagnose miscarriage based on growth in MSD and CRL are potentially unsafe. However, finding an empty gestational sac on two scans more than 7 days apart is highly likely to indicate miscarriage, irrespective of growth.

A model and scoring system to predict outcome of intrauterine pregnancies of uncertain viability

OBJECTIVES

To define the incidence and outcome of intrauterine pregnancy of uncertain viability (PUV) and to develop and assess the performance of a model and a scoring system to predict ongoing viability.

METHODS

Of 1881 consecutive women undergoing transvaginal ultrasonography, a cohort of 493 women with an empty gestational sac < 20 mm in mean diameter, gestational sac < 25 mm in mean diameter and containing yolk sac only or an embryonic pole < 6 mm in maximum length and without visible heart activity were followed until the end of the first trimester. Women with multiple pregnancies or who underwent termination of pregnancy were excluded. Outcome measures were pregnancy viability at initial 7-14-day follow-up and first-trimester viability at 11-14 weeks. The data were split randomly into two sets (two-thirds and one-third, respectively) in order to first develop and then test a mathematical model and a 'simple' model in the prediction of viability at each outcome point, based on maternal demographics, ultrasound features and symptoms. The performance of each system was assessed by receiver-operating characteristics (ROC) curve analysis and calibration plots on a test dataset.

RESULTS

The incidence of PUV in this population was 29.2% (549/1881). Of the 493 pregnancies with initial (7-14 days) follow-up available, 307 (62.3%) were viable at this time and of the 444 pregnancies with follow-up at the end of the first trimester, 225 (50.7%) were still viable. Initial (7-14-day) viability was predicted by the model with an area under the ROC curve (AUC) of 0.837 (95% CI, 0.791-0.884) in the training dataset and 0.821 (95% CI, 0.756-0.885) in the test dataset. First-trimester (11-14-week) viability was predicted by the model with an AUC of 0.788 (95% CI, 0.734-0.842) in the training dataset and 0.774 (95% CI, 0.701-0.848) in the test dataset. The scoring system performed slightly worse than did the model, but had the advantage of being easily applicable.

CONCLUSIONS

When early pregnancy viability cannot be established immediately with ultrasound, use of either a logistic regression model or a scoring system allows an individualized prediction of first-trimester outcome.

Use of a structured reminiscence protocol to decrease depression in older women

Depression is a major public health problem for older women. Medications do not always decrease depression. Therefore, there is a need to research alternative approaches to dealing with depression in this age group. Structured reminiscence has been suggested as a cognitive behaviour approach for dealing with depression in older women. However, the research is limited. This article presents a research study using a structured reminiscence protocol to decrease depression in older women. This study found significant positive results. First, structured reminiscence decreases depression levels of women 60 years and older residing in assisted living facilities when offered twice weekly for 6-week duration to document significant improvement in depression scores. Second, engagement in reminiscence must occur longer than 3 weeks to measure a significant improvement in depression scores. The study also recommends screening of all older women admitted to assisted living facilities for depression on admission and offering education to nurses working with older adults to educate them on the positive effects of structured reminiscence group interventions.

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.

Viability of intrauterine pregnancy in women with pregnancy of unknown location: prediction using human chorionic gonadotropin ratio vs. progesterone

OBJECTIVES

To find the best predictor of the viability of intrauterine pregnancies of uncertain viability (IPUVs). An IPUV is defined as an empty intrauterine gestational sac measuring less than 20 mm in diameter or an intrauterine gestational sac containing a fetal pole with a crown-rump length (CRL) of less than 6 mm with no fetal cardiac activity.

METHODS

This was a prospective observational study comparing the following two markers for the prediction of viability in IPUVs: human chorionic gonadotropin (hCG) ratio (hCG 48 h : hCG 0 h); and serum progesterone at first presentation. All women classified with a pregnancy of unknown location (PUL) were followed up until final diagnosis: failing PUL, viable or non-viable intrauterine pregnancy (IUP), or ectopic pregnancy. Those PULs found to have an IPUV at follow-up transvaginal ultrasound scan (TVS) were included in the final analysis. Receiver-operating characteristics (ROC) curves were used to compare the performance of the hCG ratio and progesterone. Using logistic regression, the added value of combining both variables over single-variable prediction was also evaluated. Missing values were imputed using multiple imputation.

RESULTS

In total, 12 572 consecutive first-trimester women were scanned. Of these, 1003 (8%) women were classified as having PULs at first scan; 379 (37.8%) PULs were confirmed as IPUVs at follow-up scan, with 82.6% (276/334) found to be viable IUPs and 17.4% (58/334) non-viable IUPs on a second follow-up scan. Forty-five PULs were lost to follow-up. For prediction of viability in IPUVs, the area under the ROC curve (AUC) for the hCG ratio was 0.756 (95% CI, 0.686-0.826) whilst that for progesterone was 0.678 (95% CI, 0.603-0.753). The difference in AUC was 0.078 (95% CI, 0.014-0.169, P = 0.098), suggesting that the hCG ratio was at least as good as initial progesterone. Furthermore, there was no clear threshold for initial progesterone, whilst for hCG a ratio of 2 was suggested (sensitivity 78%, specificity 67%). Logistic regression modeling demonstrated that progesterone did not improve the discriminatory power of the hCG ratio (AUC = 0.758).

CONCLUSIONS

The hCG ratio may be preferred to single measurements of progesterone to predict the viability of IPUVs in the PUL population.

Twin growth discrepancy in early pregnancy

OBJECTIVES

To assess whether early fetal growth restriction in a twin, expressed as the intertwin discrepancy in crown-rump length (CRL) between two viable twins at 7 + 0 to 9 + 6 weeks' gestation, is predictive of subsequent single fetal loss.

METHODS

This was a retrospective analysis of data collected prospectively over 3 years. Women attending an early pregnancy unit underwent a transvaginal ultrasound examination. In women with a viable twin pregnancy between 7 + 0 and 9 + 6 weeks of gestation, the CRL ratio between the two embryos was calculated. Women were followed up and the intertwin discrepancy in CRL at the 7 + 0 to 9 + 6-week scan was compared between cases in which there was spontaneous reduction to a singleton and those in which both twins remained viable at the 11-14-week scan.

RESULTS

There were 77 women included in the study and nine (12%) of these had a single fetal loss. Pregnancies with subsequent single fetal loss were more likely to have a larger median CRL discrepancy (42.0%; interquartile range (IQR), 23.8-64.3%) than were those which retained two viable fetuses (6.1%; IQR, 2.2-12.5%) (P < 0.0001). The median CRL discrepancy in subsequently viable monochorionic diamniotic twins (10.9%; IQR, 1.9-17.5%) was no different from that in dichorionic diamniotic twin pregnancies (5.9%; IQR, 2.1-12.3%) (P = 0.305). Regardless of chorionicity, there was a relationship between increasing CRL discrepancy and single fetal loss; the likelihood of a subsequently viable twin pregnancy was 97% if the discrepancy was < 20%, while if the discrepancy was > 60% there were no cases of both twins remaining viable (P < 0.0001). Receiver-operating characteristics curve analysis of CRL discrepancy in predicting single fetal loss gave an area under the curve of 0.93, with an optimum cut-off point of 16.9% discrepancy (sensitivity, 88.9%; 95% CI, 51.8-99.7; and specificity, 86.7%; 95% CI, 76.3-93.8).

CONCLUSION

There is a significant relationship between CRL discrepancy at 7 + 0 to 9 + 6 weeks and the likelihood of subsequent single intrauterine fetal loss. This suggests that spontaneous fetal demise of one twin may be preceded by growth restriction in the first trimester.

Functional linear discriminant analysis: a new longitudinal approach to the assessment of embryonic growth

BACKGROUND

Functional linear discriminant analysis (FLDA) is a new growth assessment technique using serial measurements to discriminate between normal and abnormal fetal growth. We used FLDA to assess and compare growth in live pregnancies destined to miscarry with those remaining viable.

METHODS

This was a prospective cohort study of women with ultrasound scans on at least two separate occasions showing live pregnancies. Serial crown-rump length (CRL), mean gestational sac diameter and mean yolk sac diameter measurements were recorded. The ability of FLDA to predict subsequent miscarriage was compared with that of a single CRL measurement.

RESULTS

Of 521 included pregnancies, 493 (94.6%) remained viable at 14 weeks and 28 (5.4%) miscarried. The CRL growth rate was significantly lower in those that miscarried (one-sample t-test, P = 2.638E-22). The sensitivity of FLDA in predicting miscarriage from serial CRL measurements was 60.7% and specificity was 93.1% [positive predictive value (PPV) 33.3%, negative predictive value (NPV) 97.7%]. This was significantly better for predicting miscarriage than a single CRL observation of more than 2SD below that expected (sensitivity 53.6%, specificity 72.2%, PPV 9.9%, NPV 96.5%).

CONCLUSIONS

FLDA discriminates between normal and abnormal growth to predict miscarriage with high specificity. FLDA predicts miscarriage better than a single observation of a small CRL.

Reliability of transvaginal ultrasonography at 7-9 weeks' gestation in the determination of chorionicity and amnionicity in twin pregnancies

OBJECTIVES

To assess the agreement in the diagnosis of chorionicity and amnionicity between transvaginal ultrasound examination at 7-9 weeks' gestation and at the 11-14-week transabdominal scan.

METHODS

This was a retrospective analysis of prospectively collected data of twin pregnancies over a 3-year period. Chorionicity and amnionicity were assessed in women with viable twin pregnancies who underwent a transvaginal ultrasound scan at between 7 and 9 weeks' gestation. These findings were compared with the diagnoses of chorionicity and amnionicity at the subsequent 11-14-week scan in these women.

RESULTS

Chorionicity and amnionicity were documented in 67 viable twin pregnancies at both 7-9 and 11-14 weeks' gestation. There was agreement in the chorionicity and amnionicity reported at each of the two scans in 65 out of 67 (97%) cases. Of the dichorionic-diamniotic (DCDA) pregnancies reported at 7-9 weeks, 53 out of 54 (98%) were confirmed at the 11-14-week scan and one (2%) was found to be monochorionic-diamniotic (MCDA). However, at birth these twins were of different sex, confirming DCDA twins as initially diagnosed at 7-9 weeks. Of the 12 pregnancies diagnosed as MCDA at 7-9 weeks, all were found to be MCDA at the 11-14-week scan. There was one monochorionic-monoamniotic (MCMA) pregnancy diagnosed at 7-9 weeks that was subsequently found to be MCDA at the 11-14-week scan.

CONCLUSION

Transvaginal ultrasound examination at 7-9 weeks' gestation shows very high agreement with the 11-14-week scan in the diagnosis of chorionicity and amnionicity in twin pregnancies, suggesting that it provides a similar level of accuracy. Accuracy may be higher for DC twins than MC twins, which may relate to the gestational age at which the sonographic appearance of the amniotic sac develops.

Evidence of early first-trimester growth restriction in pregnancies that subsequently end in miscarriage

OBJECTIVES

To examine whether viable early pregnancies that subsequently end in miscarriage exhibit evidence of first-trimester growth restriction.

DESIGN

Prospective cohort study.

SETTING

Early pregnancy unit (EPU) of a teaching hospital.

POPULATION

Women attending EPU between 5 and 10 weeks of gestation.

METHODS

Women with spontaneously conceived intrauterine, viable singleton pregnancies with certain last menstrual period and regular cycles were included. The deviation between the observed and expected crown-rump length (CRL) for gestation was calculated and expressed as a z score. Pregnancies were followed up until the 11-14 week scan, and the deviation between those that remained viable and miscarried subsequently was calculated.

MAIN OUTCOME MEASURES

Viability at 11-14 week scan.

RESULTS

Over 6 months, 316 women met the inclusion criteria. Twenty-four (7.4%) women were excluded. Of the remaining 292, the pregnancy remained viable in 251 (86%) and 41 (14%) suffered a miscarriage. At the first transvaginal ultrasound, the z score of the mean measured CRL for pregnancies that remained viable was -0.82, SD 1.46, while in pregnancies that subsequently miscarried the z score was -2.42 and the CRL was significantly smaller, SD 1.31 (P < 0.0001). In the latter group, the initial CRL was below the expected mean for gestational age in all women, while in 61% (25/41), the CRL was at least 2 SDs below the expected mean.

CONCLUSIONS

CRL was significantly smaller in pregnancies that subsequently ended in miscarriage. This suggests that early first-trimester growth restriction is associated with subsequent intrauterine death.

Prediction of ectopic pregnancy in women with a pregnancy of unknown location

OBJECTIVE

We have previously published on the use of mathematical Model M1 to predict ectopic pregnancy in women with no signs of intra- or extrauterine pregnancy. The aim of this study was to improve on the performance of this model for the detection of developing ectopic pregnancies in women with pregnancies of unknown location (PULs). We therefore generated and evaluated a new logistic regression model from simple hormonal data and compared it with Model M1.

METHODS

Data were collected prospectively from women classified as having a PUL. These women were followed until the diagnosis was established as: a failing PUL, an intrauterine pregnancy (IUP) or an ectopic pregnancy. A multinomial logistic regression model, Model M4, was developed on 201 training cases and it was tested prospectively on another 175 women with a PUL. M4 performance was evaluated using receiver-operating characteristics (ROC) curves and compared with Model M1 based on the human chorionic gonadotropin (hCG) ratio alone.

RESULTS

A total of 376 women with a PUL were recruited into this study: 201 in the training set (109 (54.2%) with a failing PUL, 76 (37.8%) with an IUP and 12 (6.0%) with an ectopic pregnancy; four with a persisting PUL were excluded from analysis) and 175 in the test set (94 (53.7%) with a failing PUL, 64 (36.6%) with an IUP and 15 (8.6%) with an ectopic pregnancy; two with a persisting PUL were excluded from analysis). The log serum hCG average ((hCG 0 h + hCG 48 h)/2) and the hCG ratio (hCG 48 h/hCG 0 h) were encoded as variables following multivariate analysis of the basic data. The new Model M4 contained the log of the hCG average, the hCG ratio and its quadratic effect. In the prediction of ectopic pregnancy, M4 gave an area under the ROC curve (AUC) of 0.900 and M1 gave an AUC of 0.842 (P = 0.0303).

CONCLUSIONS

Although Model M4 is superior to Model M1 when comparing the AUCs for prediction of developing ectopic pregnancies in a PUL population, in real terms this model did not result in substantially more pregnancies being classified correctly as developing ectopic pregnancies. Prospective multicenter studies are needed to assess the diagnostic performance of such models in different populations.

Rationalizing the follow-up of pregnancies of unknown location

BACKGROUND

To develop a strategy to rationalize the follow-up of pregnancies of unknown location (PULs) based on the predicted outcome using a mathematical model.

METHODS

Prospective interventional study. Women classified with a PUL had serum hCG levels taken at 0 and 48 h. A logistic regression model was used to predict PUL outcome at 48 h. Women were managed according to the model's prediction. If the model predicted an intrauterine pregnancy (IUP) or ectopic pregnancy (EP), women underwent a repeat scan on day 7; if the model predicted a failing PUL and the hCG ratio was also <0.87, these women were discharged; if the model predicted a failing PUL and the hCG ratio was > or =0.87, serum hCG was repeated on day 7.

RESULTS

Three hundred and sixty-three PULs were included; the final clinical outcomes were 22 (63.1%) failing PULs, 111 (30.6%) IUPs and 23 (6.3%) EPs. 88.7% (322/363) had the location of their pregnancy confirmed in the time period according to the study protocol, i.e. day 2 for failing PULs, day 7 for IUPs and EPs. By day 7, 97.5% (354/363) had been given a diagnosis and could be eliminated from any further follow-up. Only one woman (0.3%) underwent surgical intervention for the diagnosis of her pregnancy location-a diagnostic laparoscopy and surgical evacuation.

CONCLUSION

The logistic regression model developed could be used as a basis on which to rationalize the management of PULs as it can successfully minimize their follow-up by reducing the number of visits, scans and blood tests, as well as intervention rates.

The accuracy of first trimester ultrasound in the diagnosis of hydatidiform mole

OBJECTIVE

Previous studies have examined ultrasound findings in histopathologically confirmed cases of hydatidiform mole. The aim of this study was to assess the first-trimester ultrasonographic findings in all women suspected of having hydatidiform mole on ultrasound and those subsequently diagnosed with hydatidiform mole after histological examination of removed products of conception after surgical evacuation of the uterus. The aim was to obtain a true sensitivity and positive predictive value for ultrasound in the diagnosis of hydatidiform mole.

METHODS

A retrospective analysis was performed of all cases of sonographically suspected hydatidiform mole and histologically proven hydatidiform mole presenting to the Early Pregnancy Unit of an inner city hospital over a 4-year period. The sensitivity and positive predictive value (PPV) of ultrasound in the detection of histologically proven hydatidiform mole was calculated.

RESULTS

The study group consisted of 90 women; 56 were suspected of having hydatidiform mole on ultrasound, and of these 27 (48%) had hydatidiform mole confirmed after histopathological examination of the products of conception, while no changes suggestive of hydatidiform mole were present in the other 29 cases. Overall, 61 women had hydatidiform mole confirmed on histology-41 (67%) partial hydatidiform moles (PHM) and 20 (33%) complete hydatidiform moles (CHM). The ultrasound findings in the 34 cases not suspected of hydatidiform mole were an empty sac in 8/34 (24%) women and a delayed miscarriage in the other 26/34 (76%). The overall sensitivity and positive predictive value for the ultrasound diagnosis of hydatidiform mole was 44% and 48%, respectively. For PHMs the respective values were 20% and 22% and for CHMs they were 95% and 40%.

CONCLUSION

Ultrasonography is more reliable for diagnosing CHMs than for PHMs. Overall, the sensitivity of ultrasound for accurately predicting hydatidiform mole is 44%, and one in two women with an abnormal scan will have the disease confirmed on histology.

Prospective cross-validation of three methods of predicting failing pregnancies of unknown location

BACKGROUND

We compared the performance of each of three tests for predicting pregnancy failure in the pregnancy of unknown (PUL) population.

METHODS

In a prospective observational study, we compared the performance of three models for the prediction of pregnancy failure in women with a PUL: (i) logistic-regression model incorporating vaginal bleeding, endometrial thickness (ET), initial serum progesterone and hCG levels; (ii) serum progesterone at 0 h; and (3) the hCG ratio.

RESULTS

A total of 5942 consecutive pregnant women attending the Early Pregnancy Unit were scanned and 439 (7.4%) were classified as PULs. Of these women, 420 had complete data for serum hCG at 0 and 48 h, the hCG ratio, serum progesterone at 0 h, vaginal bleeding and ET. The final outcomes were 219 (52.1%) failing PULs, 167 (39.8%) intra-uterine pregnancies and 34 (8.1%) ectopic pregnancies. For the prediction of pregnancy failure in the PUL population, the area under the receiver operating characteristic (ROC) curve (AUC) for the logistic-regression model was 0.907 (Standard error (SE) 0.015), the AUC for serum progesterone was 0.952 (SE 0.010) and the AUC for the hCG ratio was 0.980 (SE 0.004). This improved performance of the hCG ratio was significant when compared with that of initial serum progesterone (P = 0.0076) and the logistic-regression model (P < 0.0001). Using the hCG ratio cut-offs of < 0.87 and <or=0.79, the serum progesterone cut-off of < 20 nmol l(-1) and the logistic-regression cut-off of >70% for the prediction of failing PUL, sensitivities were 86.3 and 82.2% (S), 87.2% (NS) and 78.1% (S), specificities were 97.0 and 98.0% (NS), 89.6% (S) and 88.6% (S), positive-likelihood ratios were 28.91, 41.30, 8.34 and 6.82 and negative-likelihood ratios were 0.14, 0.18, 0.14 and 0.25, respectively.

CONCLUSION

The hCG ratio seems to be an optimal test for the prediction of pregnancy failure in a PUL population. The hCG ratio cut-off of 0.79 is recommended on the basis of minimizing risk to those PULs discharged at 48 h. Most importantly, when the hCG ratio is below a particular cut-off, these women can be discharged at 48 h without intervention and need for further follow-up.

A validation of the most commonly used protocol to predict the success of single-dose methotrexate in the treatment of ectopic pregnancy

BACKGROUND

Currently, the likely success of single-dose methotrexate (MTX) (50 mg/m(2)) for the treatment of ectopic pregnancy is indicated by a >15% decrease in hCG from days 4-7 after administration. The aim of this study was to assess this protocol and to develop new rules that could be used to predict the outcome at an earlier stage.

METHODS

Data were collected prospectively. Women receiving MTX for an ectopic pregnancy had serum hCG and progesterone levels checked on days 1, 3, 4, 5 and 7. Other factors including age, gestational age, previous obstetric history and ultrasound findings were recorded. The women were followed up until the outcome of medical management was known. Univariate analysis was performed to determine the benefit of the '15% day 4-7 rule', as well as to develop new rules, which potentially could be used to predict the likelihood of success before 7 days. Historical and ultrasound variables were also analysed to identify the significant variables associated with successful conservative management.

RESULTS

The success rate of single-dose MTX was 68.1% (47/69). A second dose was required in 18.8% (13/69) of cases, and it was successful in 84.6% (11/13). The 15% day 4-7 rule correctly predicted the outcome in 90.3% of cases [sensitivity 93.0%, specificity 84.2%, positive predictive value (PPV) 93.0% and negative predictive value (NPV) 84.2%, Fisher exact test P-value < 0.0001]. New rules were developed based on the percentage change day 4-5 and logistic regression models incorporating day 5 hCG levels and ultrasound findings. These new rules did not outperform the current 15% day 4-7 rule.

CONCLUSIONS

We have confirmed that a 15% decrease in serum hCG between day 4 and day 7 is a very good indicator of the likely success of MTX. The development of new rules did not significantly improve our ability to predict a successful outcome at an earlier stage.

Impact of the availability of sonography in the acute gynecology unit

OBJECTIVE

The initial assessment of acute gynecology patients is usually based on history and clinical examination and does not involve ultrasound. The aim of this study was to investigate the impact of the availability of transvaginal sonography at the time of initial assessment of the emergency gynecology patient.

METHODS

This was a prospective observational study carried out over a 5-month period in the acute gynecology unit of an inner London teaching hospital. Women were assessed in the routine manner by history-taking and clinical examination and questionnaires were completed by the doctors, including details of the intention to treat. Transvaginal ultrasound examinations were then performed and a second diagnosis and management plan were made utilizing the extra information from the scan. The plans for clinical management before and after the ultrasound examination were compared.

RESULTS

We originally recruited 1000 consecutive women to the study. The mean age was 31.1 (SD, 9.81) years. Complete data were available for 920 (92%). 84 (9.1%) women did not require a scan. Of the 521 women with a positive pregnancy test, 75.6% were reassured immediately that their pregnancy was intrauterine. 143 women (27.4%) were given the diagnosis of a suspected ectopic pregnancy before sonography, compared with 29 (5.6%) after. Following the ultrasound examination there was a change in clinical management in 54.1% of the women with a positive pregnancy test and a reduction in admissions (including inpatient theater admissions) (from 40.3% to 17.1%) and outpatient follow-up examinations (from 41.1% to 35.5%). In 90 (23.8%) non-pregnant women a significant ovarian cyst (> 5 cm) was suspected clinically; 28/90 (31.1%) were confirmed on sonography. Following the ultrasound examination there was a change in clinical management for 38.1% of non-pregnant women and a reduction in admissions (from 37.1% to 19.4%) and outpatient follow-up examinations (from 25.7% to 18.1%).

CONCLUSION

It appears that the availability of transvaginal sonography at the time of initial assessment of emergency gynecology patients improves diagnostic accuracy and reduces unnecessary admissions and follow-up examinations.

There is no role for uterine curettage in the contemporary diagnostic workup of women with a pregnancy of unknown location

BACKGROUND

The aim of this study was to generate and evaluate a new protocol that defined non-viability in the pregnancy of unknown location (PUL) population and therefore ensured no viable intra-uterine pregnancy (IUP) would be interrupted if uterine curettage was performed. A secondary aim was to evaluate published biochemical criteria that define non-viability in a PUL population to establish if these criteria could result in inadvertent termination of pregnancy (TOP) if uterine curettage was performed.

METHODS

All clinically stable women classified as having a PUL were included in this study. Protocol 1 was developed retrospectively based on data from 500 consecutive PULs. Using this protocol, no cases of viable IUPs would undergo uterine curettage and the potential for TOP was eliminated. This protocol was then validated prospectively on the data from a further 503 consecutive PULs. Results were then compared with three established criteria (Protocols 2-4) for the use of uterine curettage as a diagnostic tool to classify the location of PULs. Protocol 2 defined non-viability when the hCG ratio (hCG at 48 h/hCG at 0 h) was <or=1.66; Protocol 3 advised uterine curettage at serum hCG levels of >or=2000 U/l or when the initial serum hCG was <2000 U/l with a serum hCG rise of <35% over 48 h (hCG ratio<1.35); Protocol 4 advised uterine curettage with a serum hCG rise of <50% over 48 h (hCG ratio<1.50). The number of uterine curettages performed and viable IUPs that would have undergone an unplanned TOP were recorded for all protocols.

RESULTS

A total of 12 572 consecutive women were scanned: 1003 (8.0%) women were classified as PULs. Training set consisted of 500 PULs: 278 (55.6%) failing PULs, 176 (35.2%) IUPs and 46 (9.2%) ectopic pregnancies (EPs). Test set consisted of 503 PULs: 255 (50.7%) failing PULs, 203 (40.4%) IUPs and 45 (9.0%) EPs. Protocol 1 when developed retrospectively on the training set would have resulted in 293 uterine curettages and no potential TOP. Protocol 1 tested prospectively on 503 PULs would have resulted in 272 uterine curettages and no potential TOP. Three established criteria were tested on the entire data set (n=1003). Protocol 2 would have resulted in 114 uterine curettages and 14 (12.3%) potential TOPs; Protocol 3 would have led to 611 uterine curettages and seven (1.2%) potential TOPs; Protocol 4 would have resulted in 617 uterine curettages and three (0.5%) potential TOPs. No harm came to the women whose EP diagnosis was delayed.

CONCLUSIONS

Established criteria for the use of uterine curettage in the management of PULs, including those advocated by the American Society for Reproductive Medicine (ASRM), can theoretically result in an inadvertent TOPs. On the basis of these data, a change in contemporary clinical practice should be considered to avoid further damage to wanted pregnancies. We conclude that uterine curettage should not be used in the routine diagnostic workup of women with a PUL.

General obstetrics: Failing pregnancies of unknown location: a prospective evaluation of the human chorionic gonadotrophin ratio

OBJECTIVE

To assess the performance of the human chorionic gonadotrophin (hCG) ratio (hCG 48 hours/hCG 0 hour) to predict spontaneous resolution of pregnancies of unknown location (PUL).

DESIGN

Prospective cohort study.

SETTING

Teaching Hospital Early Pregnancy Unit.

POPULATION

Women classified as having a PUL.

METHODS

The optimal cutoff value for hCG ratio (serum hCG at 48 hours/serum hCG at 0 hours) was calculated from data on 189 consecutive PULs (the 'training set'). This cutoff was tested prospectively on a further 200 consecutive PULs (the 'test set'). The hCG ratio was also compared to absolute levels of serum hCG at 0 and 48 hour for the prediction of failing PULs.

MAIN OUTCOME MEASURES

hCG ratio in spontaneously resolving ('failing') PUL compared with those requiring intervention. Optimum cutoff determined and tested to predict spontaneously resolving PUL. Comparison of hCG ratio with absolute levels of serum hCG.

RESULTS

A total of 3996 consecutive women were scanned, of which 438 (11.0%) were classified as PULs. Complete data were available for 389 women: 189 in the training set and 200 in the test set. In the training set, there were 102 (54%) failing PUL, while 109 (55%) in the test set. hCG ratio of <0.87 predicted failing PUL, with a sensitivity of 93.1% (95% CI 85.9-97.0) and a specificity of 90.8% (95% CI 82.2-95.7) in the training set. In the test set, sensitivity was 92.7% (95% CI 85.6-96.5) and specificity was 96.7% (95% CI 90.0-99.1). The hCG ratio outperformed absolute serum hCG levels at 0 and 48 hours.

CONCLUSIONS

We have defined the optimal hCG ratio for the prediction of failing PUL. Using this cutoff, clinicians can safely adopt a noninterventional approach in women with PUL.

Predicting the outcome of pregnancies of unknown location: Bayesian networks with expert prior information compared to logistic regression

BACKGROUND

As women present at earlier gestations to early pregnancy units (EPUs), the number of women diagnosed with a pregnancy of unknown location (PUL) increases. Some of these women will have an ectopic pregnancy (EP), and it is this group in the PUL population that poses the greatest concern. The aim of this study was to develop Bayesian networks to predict EPs in the PUL population.

METHODS

Data were gathered in a single EPU from all women with a PUL. This data set was divided into a model-building (599 women with 44 EPs) and a validation (257 women with 22 EPs) data set and consisted of the following variables: vaginal bleeding, fluid in the pouch of Douglas, midline echo, lower abdominal pain, age, endometrial thickness, gestation days, the ratio of HCG at 48 and 0 h, progesterone levels (0 and 48 h) and the clinical outcome of the PUL. We developed Bayesian networks with expert information using this data set to predict EPs.

RESULTS

The best Bayesian network used the gestational age, HCG ratio and the progesterone level at 48 h and had an area under the receiver operator characteristic curve (AUC) of 0.88 for predicting EPs when tested prospectively.

CONCLUSIONS

Discrete-valued Bayesian networks are more complex to build than, for example, logistic regression. Nevertheless, we have demonstrated that such models can be used to predict EPs in a PUL population. Prospective interventional multicentre studies are needed to validate the use of such models in clinical practice.

The conservative management of cervical ectopic pregnancies

OBJECTIVE

To evaluate the role of conservative management in the treatment of cervical ectopic pregnancies.

METHODS

This was a retrospective analysis of all cervical ectopic pregnancies diagnosed in women attending our early pregnancy unit between April 1997 and September 2004 inclusive. The diagnosis of cervical ectopic pregnancy was made using transvaginal ultrasound. Clinical and demographic data were recorded in all cases. Serum human chorionic gonadotropin levels were measured at presentation and monitored subsequently to determine the rate of successful resolution. Conservative management was in the form of medical or expectant management. Medical management involved administration of systemic or intra-amniotic methotrexate, with or without intra-amniotic potassium chloride. Systemic methotrexate was either a single dose of 50 mg/m2 or an alternate-day regimen of methotrexate at 1 mg/kg (days 1,3,5) with folinic acid rescue (days 2,4,6). If intra-amniotic treatment was required, this was either 50 mg methotrexate or 5 mmol/L potassium chloride.

RESULTS

Seven cervical ectopic pregnancies were diagnosed during the study period. Three cases were managed successfully with a single dose of methotrexate. One case was managed successfully using a multiple-dose methotrexate regimen. Another case failed medical management with both the single- and multiple-dose regimens but was successfully treated after potassium chloride was given intra-amniotically under ultrasound guidance. One case was successfully treated with intra-amniotic methotrexate and another was managed expectantly. There was no associated morbidity or mortality during the study period. We also performed a review of the current literature.

CONCLUSION

The conservative management of cervical ectopic pregnancy is effective and safe.

The practical application of a mathematical model to predict the outcome of pregnancies of unknown location

OBJECTIVE

A logistic regression model has been developed previously to predict which pregnancies of unknown location (PULs) become ectopics. This model was based on the human chorionic gonadotropin (hCG) ratio (hCG 48 h/hCG 0 h). The aim of this study was to evaluate the model in an early pregnancy clinical setting.

METHODS

This was a prospective non-interventional observational study. Women classified as having a PUL had serum hCG and progesterone levels taken at presentation and 48 h later. At 48 h, nurse practitioners in the early pregnancy unit gave their subjective assessment of the likely pregnancy outcome based upon existing strategies to predict the outcome of PULs and their own previous experience. This was used as the basis for the clinical management of the women. The hormonal data were then entered into the model, which was available on the clinic computer in the form of a Microsoft Excel package, and the predicted outcome according to this model was recorded for each case. The model was weighted in favor of detecting an ectopic pregnancy at the expense of failing PULs and intrauterine pregnancies. All women were followed up until the final true diagnosis was established: a failing PUL, an intrauterine pregnancy or an ectopic pregnancy. The predicted outcome according to the model was compared with that of the subjective assessment of the expert operator and the true outcome after follow-up.

RESULTS

Data were obtained from 357 women classified as having PULs. The final clinical outcomes were: 162 (45.4%) failing PULs, 166 (46.5%) intrauterine pregnancies and 29 (8.1%) ectopic pregnancies. Subjective assessment utilizing current strategies gave sensitivities of 79.3%, 92.8% and 87.0% for the detection of ectopic pregnancy, intrauterine pregnancy and failing PUL, respectively. The model detected ectopic pregnancy, intrauterine pregnancy and failing PUL with sensitivities of 82.8%, 86.8% and 73.5%, respectively. There were no adverse outcomes.

CONCLUSION

This logistic regression model, based on the hCG ratio, can be used to predict the outcome of PULs, especially the ectopic pregnancies, with a high degree of certainty. It compares favorably with subjective assessment by experienced operators using current strategies to predict the outcome of PULs. The model can be used by those with limited knowledge or understanding of the behavior of serum biochemistry in the first trimester and in turn aid in the classification of PULs into those at low and those at high risk of ectopic pregnancy at 48 h.

The non-surgical management of ectopic pregnancy

Ectopic pregnancy can now be detected at earlier gestations in asymptomatic women. As a consequence conservative treatment strategies may be more appropriate than surgical intervention. This review aims to discuss the diagnosis and the non-surgical management options for ectopic pregnancy, in particular expectant management and the use of methotrexate.

Diagnostic accuracy of varying discriminatory zones for the prediction of ectopic pregnancy in women with a pregnancy of unknown location

OBJECTIVES

Various serum human chorionic gonadotropin (hCG) discriminatory zones are currently used for evaluating the likelihood of an ectopic pregnancy in women classified as having a pregnancy of unknown location (PUL) following a transvaginal ultrasound examination. We evaluated the diagnostic accuracy of discriminatory zones for serum hCG levels of > 1000 IU/L, 1500 IU/L and 2000 IU/L for the detection of ectopic pregnancy in such women.

METHODS

This was a prospective observational study of women who were assessed in a specialized transvaginal scanning unit. All women with a PUL had serum hCG measured at presentation. Expectant management of PULs was adopted. These women were followed up with transvaginal ultrasound, monitoring of serum hormone levels and laparoscopy until a final diagnosis was established: a failing PUL, an intrauterine pregnancy (IUP), an ectopic pregnancy or a persisting PUL. The persisting PULs probably represented ectopic pregnancies which had been missed on ultrasound and these were incorporated into the ectopic pregnancy group. Three different discriminatory zones (1000 IU/L, 1500 IU/L and 2000 IU/L) were evaluated for predicting ectopic pregnancy in this PUL population.

RESULTS

A total of 5544 consecutive women presented to the early pregnancy unit between 25 June 2001 and 14 April 2003. Of these, 569 (10.3%) women were classified as having a PUL, 42 of which were lost to follow up. Of the 527 (9.5%) cases with PUL analyzed, there were 300 (56.9%) failing PULs, 181 (34.3%) IUPs and 46 (8.7%) ectopic pregnancies. Overall, 74.6% were symptomatic and 25.4% were asymptomatic (P = 8.825E-07). The sensitivity and specificity of an hCG level of > 1000 IU/L to detect ectopic pregnancy were 21.7% (10/46) and 87.3% (420/481), respectively; for an hCG level of > 1500 IU/L these values were 15.2% (7/46) and 93.4% (449/481), respectively, and for an hCG level of > 2000 IU/L they were 10.9% (5/46) and 95.2% (458/481), respectively.

CONCLUSIONS

Varying the discriminatory zone does not significantly improve the detection of ectopic pregnancy in a PUL population. A single measurement of serum hCG is not only potentially falsely reassuring but also unhelpful in excluding the presence of an ectopic pregnancy.

Do levels of serum cancer antigen 125 and creatine kinase predict the outcome in pregnancies of unknown location?

BACKGROUND

The aim of this study was to evaluate the role of maternal serum cancer antigen 125 (CA 125) and creatine kinase (CK) levels in predicting the outcome of pregnancies of unknown location (PUL).

METHODS

Prospective observational study. Women classified as PUL were recruited. Final outcome of each PUL was established: failing PUL, intrauterine pregnancy (IUP), ectopic pregnancy (EP) or persisting PUL. The persisting PUL group almost certainly represent ultrasonically missed EP and were included in EP group. Serum CK and CA 125 were measured at 0 and 48 h. The values at presentation and the change in levels after 2 days were used in the analysis. We incorporated the most significant of variables into a multinomial logistic regression model to predict all outcomes. The performance of this model was evaluated using receiver operating characteristic (ROC) curves.

RESULTS

In all, 4698 consecutive women were scanned; 403 were classified as PUL, 27 were lost to follow-up. Of the 376 women eligible, 297 had complete data and therefore were recruited. Mean age and mean gestation were 30.0 years and 43.3 days respectively. Final outcomes: 153 failing PUL (51.5%), 116 IUP (39.1%) and 28 EP (9.4%). Mean serum CK levels at 0 and 48 h were 88.5 and 86.8 IU/l respectively. Mean serum CA 125 levels at 0 and 48 h were 43.8 and 40.1 kIU/l respectively. 81.1% of women had CK and CA 125 ratios (CK 48 h/CK 0 h, CA 125 48 h/CA125 0 h) between 0.7 and 1.3. CA 125 ratio was the only significant variable in the three outcome groups (P < 0.0001). Logistic regression analysis incorporating CA 125 ratio gave an area under ROC curve of 0.782 (SE = 0.041) for failing PUL, 0.768 (SE = 0.043) for IUP and 0.560 (SE = 0.078) for EP. This model was capable of distinguishing failing PUL from IUP, but was not able to detect EP.

CONCLUSIONS

Absolute levels of serum CK and CA 125 at the defined times cannot be used to predict the outcome of PUL. Although the CA 125 ratio when incorporated into logistic regression model can distinguish failing PUL from IUP, its inability to detect the high risk PUL, i.e. the developing EP, renders it inappropriate for use in the clinical setting.