Time-effectiveness and convenience of transvaginal ultrasound probe disinfection using ultraviolet vs chlorine dioxide multistep wipe system: prospective survey study.

OBJECTIVES: To compare the efficiency, ease of use and user satisfaction of two methods of transvaginal ultrasound probe high-level disinfection: ultraviolet-C radiation (UV-C) and a chlorine dioxide multistep wipe system. METHODS: This was a prospective survey study. UV-C units were introduced into a busy early pregnancy assessment service and compared with a multiwipe system for disinfection. Before seeing each patient, healthcare professionals (HCPs) measured with a stopwatch the time taken to complete a cycle of disinfection using either UV-C or chlorine dioxide multistep wipes and responded to a quick-response (QR) code-linked survey. Additional essential tasks that could be completed before seeing the next patient during probe disinfection were also documented. Using another QR code-linked survey, data on ease of use, satisfaction with the system used and preferred system were collected. The ease of use and satisfaction with the system were rated on a 0 to 10 Likert scale (0 poor, 10 excellent). A free-text section for comments was then completed. RESULTS: Disinfection using UV-C (n = 331) was 60% faster than the chlorine dioxide multiwipe system (n = 332) (101 vs 250 s; P < 0.0001). A greater number of tasks were completed during probe disinfection when using UV-C, saving a further 74 s per patient (P < 0.0001). The HCPs using UV-C (n = 71) reported greater ease of use (median Likert score, 10 vs 3; P < 0.0001) and satisfaction (median Likert score, 10 vs 2; P < 0.0001) compared with those using the multiwipe system (n = 43). HCPs reported that the chlorine dioxide system was time-consuming and environmentally unfriendly, while the UV-C system was efficient and easy to use. Overall, 98% of the HCPs preferred using the UV-C system. CONCLUSIONS: UV-C technology is more time-efficient and allows more essential tasks to be completed during disinfection. For a 4-h ultrasound list of 15 patients, the use of UV-C would save 55 min 45 s. HCPs found UV-C preferable and easier to use. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

External validation of models to predict the outcome of pregnancies of unknown location: a multicentre cohort study.

OBJECTIVE: To validate externally five approaches to predict ectopic pregnancy (EP) in pregnancies of unknown location (PUL): the M6P and M6NP risk models, the two-step triage strategy (2ST, which incorporates M6P), the M4 risk model, and beta human chorionic gonadotropin ratio cut-offs (BhCG-RC). DESIGN: Secondary analysis of a prospective cohort study. SETTING: Eight UK early pregnancy assessment units. POPULATION: Women presenting with a PUL and BhCG >25 IU/l. METHODS: Women were managed using the 2ST protocol: PUL were classified as low risk of EP if presenting progesterone ≤2 nmol/l; the remaining cases returned 2 days later for triage based on M6P. EP risk ≥5% was used to classify PUL as high risk. Missing values were imputed, and predictions for the five approaches were calculated post hoc. We meta-analysed centre-specific results. MAIN OUTCOME MEASURES: Discrimination, calibration and clinical utility (decision curve analysis) for predicting EP. RESULTS: Of 2899 eligible women, the primary analysis excluded 297 (10%) women who were lost to follow up. The area under the ROC curve for EP was 0.89 (95% CI 0.86-0.91) for M6P, 0.88 (0.86-0.90) for 2ST, 0.86 (0.83-0.88) for M6NP and 0.82 (0.78-0.85) for M4. Sensitivities for EP were 96% (M6P), 94% (2ST), 92% (N6NP), 80% (M4) and 58% (BhCG-RC); false-positive rates were 35%, 33%, 39%, 24% and 13%. M6P and 2ST had the best clinical utility and good overall calibration, with modest variability between centres. CONCLUSIONS: 2ST and M6P performed best for prediction and triage in PUL. TWEETABLE ABSTRACT: The M6 model, as part of a two-step triage strategy, is the best approach to characterise and triage PULs.

Differences in post-traumatic stress, anxiety and depression following miscarriage or ectopic pregnancy between women and their partners: multicenter prospective cohort study.

OBJECTIVES: To investigate and compare post-traumatic stress (PTS), depression and anxiety in women and their partners over a 9-month period following miscarriage or ectopic pregnancy. METHODS: This was a prospective cohort study. Consecutive women and their partners were approached in the early pregnancy units of three hospitals in central London. At 1, 3 and 9 months after early pregnancy loss, recruits were e-mailed links to surveys containing the Hospital Anxiety and Depression Scale and the Post-traumatic Stress Diagnostic Scale. The proportion of participants meeting the screening criteria for moderate or severe anxiety or depression and PTS was assessed. Mixed-effects logistic regression was used to analyze differences between women and their partners and their evolution over time. RESULTS: In total, 386 partners were approached after the woman in whom the early pregnancy loss had been diagnosed consented to participate, and 192 couples were recruited. All partners were male. Response rates were 60%, 48% and 39% for partners and 78%, 70% and 59% for women, at 1, 3 and 9 months, respectively. Of the partners, 7% met the criteria for PTS at 1 month, 8% at 3 months and 4% at 9 months, compared with 34%, 26% and 21% of women, respectively. Partners also experienced lower rates of moderate/severe anxiety (6% vs 30% at 1 month, 9% vs 25% at 3 months and 6% vs 22% at 9 months) and moderate/severe depression (2% vs 10% at 1 month, 5% vs 8% at 3 months and 1% vs 7% at 9 months). The odds ratios for psychological morbidity in partners vs women after 1 month were 0.02 (95% CI, 0.004-0.12) for PTS, 0.05 (95% CI, 0.01-0.19) for moderate/severe anxiety and 0.15 (95% CI, 0.02-0.96) for moderate/severe depression. Morbidity for each outcome decreased modestly over time, without strong evidence of a different evolution between women and their partners. CONCLUSIONS: Some partners report clinically relevant levels of PTS, anxiety and depression after pregnancy loss, though to a far lesser extent than women physically experiencing the loss. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

The association between vaginal bacterial composition and miscarriage: a nested case-control study.

OBJECTIVE: To characterise vaginal bacterial composition in early pregnancy and investigate its relationship with first and second trimester miscarriages. DESIGN: Nested case-control study. SETTING: Queen Charlotte's and Chelsea Hospital, Imperial College Healthcare NHS Trust, London. POPULATION: 161 pregnancies: 64 resulting in first trimester miscarriage, 14 in second trimester miscarriage and 83 term pregnancies. METHODS: Prospective profiling and comparison of vaginal bacteria composition using 16S rRNA gene-based metataxonomics from 5 weeks' gestation in pregnancies ending in miscarriage or uncomplicated term deliveries matched for age, gestation and body mass index. MAIN OUTCOME MEASURES: Relative vaginal bacteria abundance, diversity and richness. Pregnancy outcomes defined as first or second trimester miscarriage, or uncomplicated term delivery. RESULTS: First trimester miscarriage associated with reduced prevalence of Lactobacillus spp.-dominated vaginal microbiota classified using hierarchical clustering analysis (65.6 versus 87.7%; P = 0.005), higher alpha diversity (mean Inverse Simpson Index 2.5 [95% confidence interval 1.8-3.0] versus 1.5 [1.3-1.7], P = 0.003) and higher richness 25.1 (18.5-31.7) versus 16.7 (13.4-20), P = 0.017), compared with viable pregnancies. This was independent of vaginal bleeding and observable before first trimester miscarriage diagnosis (P = 0.015). Incomplete/complete miscarriage associated with higher proportions of Lactobacillus spp.-depleted communities compared with missed miscarriage. Early pregnancy vaginal bacterial stability was similar between miscarriage and term pregnancies. CONCLUSIONS: These findings associate the bacterial component of vaginal microbiota with first trimester miscarriage and indicate suboptimal community composition is established in early pregnancy. While further studies are required to elucidate the mechanism, vaginal bacterial composition may represent a modifiable risk factor for first trimester miscarriage. TWEETABLE ABSTRACT: Vaginal bacterial composition in first trimester miscarriage is associated with reduced Lactobacillus spp. abundance and is independent of vaginal bleeding.

Natural history of pregnancy-related enhanced myometrial vascularity following miscarriage.

OBJECTIVES: Our primary aim was to report the incidence of enhanced myometrial vascularity (EMV) in consecutive women attending our early pregnancy assessment unit, following first-trimester miscarriage. We aimed further to evaluate the clinical presentation and complications associated with expectant and surgical management of EMV in these women. METHODS: This was a prospective cohort study conducted in a London teaching hospital between June 2015 and June 2018, including consecutive patients with an observation of EMV on transvaginal ultrasonography following first-trimester miscarriage. The diagnosis was made following the subjective identification of EMV using color Doppler ultrasonography and a peak systolic velocity (PSV) ≥ 20 cm/s within the collection of vessels. Women were followed up with repeat scans every 14 days. Management was expectant unless intervention was indicated because of excessive or prolonged bleeding, persistent presence of retained tissue in the endometrial cavity or patient choice. The final clinical outcome was recorded. Time to resolution of EMV was defined as the interval from detection of EMV until resolution. RESULTS: During the study period, there were 2627 first-trimester fetal losses in the department and, of these, 40 patients were diagnosed with EMV, hence the incidence of EMV following miscarriage was 1.52%. All cases were associated with ultrasound evidence of retained products of conception (RPOC) at presentation (mean dimensions, 22 × 20 × 20 mm). Thirty-one patients opted initially for expectant management, of which 18 had successful resolution without intervention, five were lost to follow-up and eight subsequently had surgical evacuation due to patient choice. No expectantly managed case required emergency intervention. Nine patients chose surgical evacuation as primary treatment. No significant correlation was seen between PSV within the EMV at presentation and blood loss at surgery. Median PSV was 47 (range, 20-148) cm/s. The estimated blood loss in all cases managed surgically ranged from 20-300 mL. Presence of RPOC was confirmed in all specimens that were sent for analysis following surgery. For cases successfully managed expectantly, the mean time to resolution was 48 (range, 21-84) days. In the nine cases managed surgically from the beginning, the mean time to resolution of EMV was 10.6 (range, 3-29) days. CONCLUSIONS: This study suggests that EMV is an uncommon finding following miscarriage and is associated with the presence of RPOC. Expectant management was a safe option in our cohort, with minimal bleeding, although it was associated with protracted time to resolution. In patients who opted for surgery, the maximum blood loss was 300 mL and no patient required blood transfusion or embolization. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

First-trimester intrauterine hematoma and pregnancy complications.

OBJECTIVE: To assess whether sonographic diagnosis of intrauterine hematoma (IUH) in the first trimester of pregnancy is associated with first-trimester miscarriage and antenatal, delivery and neonatal complications. METHODS: This was a prospective observational cohort study of women with an intrauterine singleton pregnancy between 5 and 14 weeks' gestation recruited at Queen Charlotte's and Chelsea Hospital, London, UK, between March 2014 and March 2016. Participants underwent serial ultrasound examinations in the first trimester, and the presence, location, size and persistence of any IUH was evaluated. First-trimester miscarriage was defined as pregnancy loss before 14 weeks' gestation. Clinical symptoms, including pelvic pain and vaginal bleeding, were recorded at each visit using validated symptom scores. Antenatal, delivery and neonatal outcomes were obtained from hospital records. Logistic regression analysis and the chi-square test were used to assess the association between the presence and features of IUH and the incidence of adverse pregnancy outcome. Odds ratios (OR) were first adjusted for maternal age (aOR) and then further adjusted for the presence of vaginal bleeding or pelvic pain in the first trimester. RESULTS: Of 1003 women recruited to the study, 946 were included in the final analysis and of these, 268 (28.3%) were diagnosed with an IUH in the first trimester. The presence of IUH was associated with the incidence of preterm birth (aOR, 1.94 (95% CI, 1.07-3.52)), but no other individual or overall antenatal, delivery or neonatal complications. No association was found between the presence of IUH in the first trimester and first-trimester miscarriage (aOR, 0.81 (95% CI, 0.44-1.50)). These findings were independent of the absolute size of the hematoma and the presence of vaginal bleeding or pelvic pain in the first trimester. When IUH was present in the first trimester, there was no association between its size, content or position in relation to the gestational sac and overall antenatal, delivery and neonatal complications. Diagnosis of a retroplacental IUH was associated with an increased risk of overall antenatal complications (P = 0.04). CONCLUSIONS: Our findings demonstrate that there is no association between the presence of IUH in the first trimester and first-trimester miscarriage. However, an association with preterm birth, independently of the presence of symptoms of pelvic pain and/or vaginal bleeding, is evident. Women diagnosed with IUH in the first trimester should be counseled about their increased risk of preterm birth and possibly be offered increased surveillance during the course of their pregnancy. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

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.

Early-pregnancy events and subsequent antenatal, delivery and neonatal outcomes: prospective cohort study.

OBJECTIVE: To assess prospectively the association between pelvic pain, vaginal bleeding, and nausea and vomiting occurring in the first trimester of pregnancy and the incidence of later adverse pregnancy outcomes. METHODS: This was a prospective observational cohort study of consecutive women with confirmed intrauterine singleton pregnancy between 5 and 14 weeks' gestation recruited at Queen Charlotte's & Chelsea Hospital, London, UK, from March 2014 to March 2016. Serial ultrasound scans were performed in the first trimester. Participants completed validated symptom scores for vaginal bleeding, pelvic pain, and nausea and vomiting. The key symptom of interest was any pelvic pain and/or vaginal bleeding during the first trimester. Pregnancies were followed up until the final outcome was known. Antenatal, delivery and neonatal outcomes were obtained from hospital records. Logistic regression analysis was used to assess the association between first-trimester symptoms and pregnancy complications by calculating adjusted odds ratios (aOR) with correction for maternal age. RESULTS: Of 1003 women recruited, 847 pregnancies were included in the final analysis following exclusion of cases due to first-trimester miscarriage (n = 99), termination of pregnancy (n = 20), loss to follow-up (n = 32) or withdrawal from the study (n = 5). Adverse antenatal complications were observed in 166/645 (26%) women with pelvic pain and/or vaginal bleeding in the first trimester (aOR = 1.79; 95% CI, 1.17-2.76) and in 30/181 (17%) women with no symptoms. Neonatal complications were observed in 66/634 (10%) women with and 11/176 (6%) without pelvic pain and/or vaginal bleeding (aOR = 1.73; 95% CI, 0.89-3.36). Delivery complications were observed in 402/615 (65%) women with and 110/174 (63%) without pelvic pain and/or vaginal bleeding during the first trimester (aOR = 1.16; 95% CI, 0.81-1.65). For 18 of 20 individual antenatal complications evaluated, incidence was higher among women with pelvic pain and/or vaginal bleeding, despite the overall incidences being low. Nausea and vomiting in pregnancy showed little association with adverse pregnancy outcomes. CONCLUSIONS: Our study suggests that there is an increased incidence of antenatal complications in women experiencing pelvic pain and/or vaginal bleeding in the first trimester. This should be considered when advising women attending early-pregnancy units. Copyright © 2019 ISUOG. Published by John Wiley & Sons Ltd.

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.

Can risk factors, clinical history and symptoms be used to predict risk of ectopic pregnancy in women attending an early pregnancy assessment unit?

OBJECTIVE: To examine whether risk factors and symptoms may be used to predict the likelihood of ectopic pregnancy (EP) in women attending early pregnancy assessment units in the UK. METHODS: This was an observational cohort study of pregnant women under 12 weeks' gestation who were recruited from three London university hospitals between August 2012 and April 2013. One hospital continued recruitment between January and June 2015. A standardized information sheet incorporating patient demographics, medical history and symptoms was completed by patients and confirmed by examining clinicians. The outcome measure was final pregnancy location. RESULTS: There were 1320 eligible patients included in the analysis, with a total of 72 EPs (rate of 6%). Pelvic pain and diarrhea > three times in the previous 24 h were independent symptoms that increased the risk of EP, with relative risks of 2.4 (95% CI, 1.4-4.0; P = 0.002) and 2.2 (95% CI, 1.08-4.5; P = 0.03), respectively. The only other independent marker of risk of EP was duration of vaginal bleeding; the risk of EP increased by 20% (95% CI, 14%-27%) for every 1-day increment in duration (P < 0.001). A logistic regression model incorporating these factors demonstrated an area under the receiver-operating characteristics curve of 0.73 (95% CI, 0.67-0.79). The prevalence of EP was low when there was no pelvic pain, no diarrhea and the duration of bleeding was ≤ 3 days, with an EP rate of 2% (6/391). In the presence of a single risk factor, the EP rate increased to 5% (29/631) when only pelvic pain was present, 8% (1/12) when only diarrhea > three times in the previous 24 h was reported and 9% (9/103) when there was only vaginal bleeding with a duration > 3 days. Women with pelvic pain and vaginal bleeding of any severity for > 3 days had a high EP rate of 16% (23/146). In the nine women who also reported diarrhea > three times in the previous 24 h, two had EP. CONCLUSIONS: Only the presence of pelvic pain, diarrhea > three times in the previous 24 h and duration of bleeding were symptoms that significantly increased the risk for EP in women attending early pregnancy assessment units. Risk factors and symptoms alone could not be used to predict reliably an EP. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Evaluating the risk of ovarian cancer before surgery using the ADNEX model: a multicentre external validation study.

BACKGROUND: The International Ovarian Tumour Analysis (IOTA) group have developed the ADNEX (The Assessment of Different NEoplasias in the adneXa) model to predict the risk that an ovarian mass is benign, borderline, stage I, stages II-IV or metastatic. We aimed to externally validate the ADNEX model in the hands of examiners with varied training and experience. METHODS: This was a multicentre cross-sectional cohort study for diagnostic accuracy. Patients were recruited from three cancer centres in Europe. Patients who underwent transvaginal ultrasonography and had a histological diagnosis of surgically removed tissue were included. The diagnostic performance of the ADNEX model with and without the use of CA125 as a predictor was calculated. RESULTS: Data from 610 women were analysed. The overall prevalence of malignancy was 30%. The area under the receiver operator curve (AUC) for the ADNEX diagnostic performance to differentiate between benign and malignant masses was 0.937 (95% CI: 0.915-0.954) when CA125 was included, and 0.925 (95% CI: 0.902-0.943) when CA125 was excluded. The calibration plots suggest good correspondence between the total predicted risk of malignancy and the observed proportion of malignancies. The model showed good discrimination between the different subtypes. CONCLUSIONS: The performance of the ADNEX model retains its performance on external validation in the hands of ultrasound examiners with varied training and experience.

The clinical performance of the M4 decision support model to triage women with a pregnancy of unknown location as at low or high risk of complications.

STUDY QUESTION: What are the adverse outcomes associated with using the M4 model in everyday clinical practice for women with pregnancy of unknown location (PUL)? SUMMARY ANSWER: There were 17/835 (2.0%) adverse events and no serious adverse events associated with the performance of the M4 model in clinical practice. WHAT IS KNOWN ALREADY: The M4 model has previously been shown to stratify women classified as a PUL as at low or high risk of complications with a good level of test performance. The triage performance of the M4 model is better than single measurements of serum progesterone or the hCG ratio (serum hCG at 48 h/hCG at presentation). STUDY DESIGN, SIZE, DURATION: A prospective multi-centre cohort study of 1022 women with a PUL carried out between August 2012 and December 2013 across 2 university teaching hospitals and 1 district general hospital. PARTICIPANTS/MATERIALS, SETTING, METHODS: All women presenting with a PUL to the early pregnancy units of the three hospitals were recruited. The final outcome for PUL was either a failed PUL (FPUL), intrauterine pregnancy (IUP) or ectopic pregnancy (EP) (including persistent PUL (PPUL)), with EP and PPUL considered high-risk PUL. Their hCG results at 0 and 48 h were entered into the M4 model algorithm. If the risk of EP was ≥5%, the PUL was predicted to be high-risk and the participant was asked to re-attend 48 h later for a repeat hCG and transvaginal ultrasound scan by a senior clinician. If the PUL was classified as 'low risk, likely failed PUL', the participant was asked to perform a urinary pregnancy test 2 weeks later. If the PUL was classified as 'low risk, likely intrauterine', the participant was scheduled for a repeat scan in 1 week. Deviations from the management protocol were recorded as either an 'unscheduled visit (participant reason)', 'unscheduled visit (clinician reason)' or 'differences in timing (blood test/ultrasound)'. Adverse events were assessed using definitions outlined in the UK Good Clinical Practice Guidelines' document. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 835 (82%) women classified as a PUL were managed according to the M4 model (9 met the exclusion criteria, 69 were lost to follow-up, 109 had no hCG result at 48 h). Of these, 443 (53%) had a final outcome of FPUL, 298 (36%) an IUP and 94 (11%) an EP. The M4 model predicted 70% (585/835) PUL as low risk, of which 568 (97%) were confirmed as FPUL or IUP. Of the 17 EP and PPUL misclassified as low risk, 5 had expectant management, 7 medical management with methotrexate and 5 surgical intervention.Nineteen PUL had an unscheduled visit (participant reason), 38 PUL had an unscheduled visit (clinician reason) and 68 PUL had deviations from protocol due to a difference in timing (blood test/ultrasound).Adverse events were reported in 26 PUL and 1 participant had a serious adverse event. A total of 17/26 (65%) adverse events were misclassifications of a high risk PUL as low risk by the M4 model, while 5/26 (19%) adverse events were related to incorrect clinical decisions. Four of the 26 adverse events (15%) were secondary to unscheduled admissions for pain/bleeding. The serious adverse event was due to an incorrect clinical decision. LIMITATIONS, REASONS FOR CAUTION: A limitation of the study was that 69/1022 (7%) of PUL were lost to follow-up. A 48 h hCG level was missing for 109/1022 (11%) participants. WIDER IMPLICATIONS OF THE FINDINGS: The low number of adverse events (2.0%) suggests that expectant management of PUL using the M4 prediction model is safe. The model is an effective way of triaging women with a PUL as being at high- and low-risk of complications and rationalizing follow-up. The multi-centre design of the study is more likely to make the performance of the M4 model generalizable in other populations. STUDY FUNDING/COMPETING INTERESTS: None. TRIAL REGISTRATION NUMBER: Not applicable.

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.