Early pregnancy complications: endovaginal sonographic findings correlated with human chorionic gonadotropin levels

Association of HCG Level with Ultrasound Visualization of the Gestational Sac in Early Viable Pregnancies

Our primary objective is to verify or refute a 2013 study by Connolly et al. which showed that in early pregnancy, a gestational sac was visualized 99% of the time on transvaginal ultrasound when the HCG level reached 3510 mIU/mL. Our secondary objective was to make clinical correlations by assessing the relationship between human chorionic gonadotropin (HCG) level in early pregnancy when a gestational sac is not seen and pregnancy outcomes of live birth, spontaneous abortion, and ectopic pregnancy. This retrospective study includes 144 pregnancies with an outcome of live birth, 87 pregnancies with an outcome of spontaneous abortion, and 59 ectopic pregnancies. Logistic regression is used to determine the probability of visualizing a gestational sac and/or yolk sac based on the HCG level. A gestational sac is predicted to be visualized 50% of the time at an HCG level of 979 mIU/mL, 90% at 2421 mIU/mL, and 99% of the time at 3994 mIU/mL. A yolk sac was predicted to be visualized 50% of the time at an HCG level of 4626 mIU/mL, 90% at 12,892 mIU/mL, and 99% at 39,454 mIU/mL. A total of 90% of ectopic pregnancies presented with an HCG level below 3994 mIU/mL. These results are in agreement with the study by Connolly et al. Since most early ectopic pregnancies had an HCG value below the discriminatory level for gestational sac visualization, other methods for the evaluation of pregnancy of unknown location such as repeat HCG values are clinically important.

Non-neoplastic diseases of the fallopian tube: MR imaging with emphasis on diffusion-weighted imaging

OBJECTIVE

We illustrate the magnetic resonance imaging (MRI) features of non-neoplastic tubaric conditions.

BACKGROUND

A variety of pathologic non-neoplastic conditions may affect the fallopian tubes. Knowledge of their imaging appearance is important for correct diagnosis. With recent advances in MRI, along with conventional MR sequences, diffusion-weighted imaging (DWI) sequences are available and may improve lesion characterization by discriminating the nature of the content of the dilated tube. Tubal fluid with low signal intensity on T1-weighted images, high signal intensity on T2-weighted images and no restricted diffusion on DWI is indicative of hydrosalpinx. Content with high signal intensity on T1-weighted images and restricted diffusion on DWI is suggestive of hematosalpinx associated with endometriosis or tubal pregnancy. A dilated tube with variable or heterogeneous signal intensity content on conventional MR sequences and restricted diffusion on DWI may suggest a pyosalpinx or tubo-ovarian abscess. We describe morphological characteristics, MR signal intensity features, enhancement behaviour and possible differential diagnosis of each lesion.

CONCLUSION

MRI is the method of choice to study adnexal pelvic masses. Qualitative and quantitative functional imaging with DWI can be of help in characterization of tubaric diseases, provided that findings are interpreted in conjunction with those obtained with conventional MRI sequences.

TEACHING POINTS

• Nondilated fallopian tubes are not usually seen on MR images. • MRI is the method of choice to characterize and localize utero-adnexal masses. • MRI allows characterization of lesions through evaluation of the fluid content's signal intensity. • DWI in conjunction with conventional MRI sequences may improve tissue characterization. • Pelvic inflammatory disease is the most common tubal pathology.

Accuracy of first-trimester ultrasound in diagnosis of tubal ectopic pregnancy in the absence of an obvious extrauterine embryo: systematic review and meta-analysis

OBJECTIVES

To determine the accuracy of ultrasound in the diagnosis of a tubal ectopic pregnancy in the absence of an obvious extrauterine embryo.

METHODS

This was a systematic review conducted in accordance with the PRISMA statement and registered with PROSPERO. We searched MEDLINE, EMBASE and The Cochrane Library for relevant citations from database inception to July 2014. Studies were selected in a two-stage process and their data extracted by two reviewers. Accuracy measures were calculated for each ultrasound sign, i.e. empty uterus, pseudosac, adnexal mass and free fluid in the pouch of Douglas, alone and in various combinations. Individual study estimates were plotted in summary receiver-operating characteristics curves and forest plots for examination of heterogeneity. The quality of included studies was assessed.

RESULTS

Thirty-one studies including 5858 women were selected from 19,959 citations. Following meta-analysis, an empty uterus on ultrasound was found to predict an ectopic pregnancy with a sensitivity of 81.1% (95% CI, 42.1-96.2%) and specificity of 79.5% (95% CI, 68.9-87.1%). The corresponding performance of the pseudosac, adnexal mass and free fluid were: 5.5% (95% CI, 3.3-9.0%) and 94.2% (95% CI, 75.9-98.8%); 63.5% (95% CI, 48.5-76.3%) and 91.4% (95% CI, 83.6-95.7%); and 47.2% (95% CI, 33.2-61.7%) and 92.3% (95% CI, 85.6-96.0%), respectively.

CONCLUSION

Visualization of an empty uterus, adnexal mass, free fluid or a pseudosac has poor sensitivity for the diagnosis of a tubal pregnancy when an obvious extrauterine embryo is absent, but it has good specificity. We can therefore infer that ultrasound is more useful for 'ruling in' a tubal pregnancy than 'ruling out' one. However, the findings were limited by the poor quality of some included studies and heterogeneity in the index test and reference standard.

Accuracy of first-trimester ultrasound in diagnosis of intrauterine pregnancy prior to visualization of the yolk sac: a systematic review and meta-analysis

OBJECTIVES

To evaluate the diagnostic accuracy of ultrasound in predicting the location of an intrauterine pregnancy before visualization of the yolk sac is possible.

METHODS

This was a systematic review conducted in accordance with the PRISMA statement and registered with PROSPERO. We searched MEDLINE, EMBASE and The Cochrane Library for relevant citations. Studies were selected in a two-stage process and their data extracted by two reviewers. Accuracy measures were calculated for each ultrasound sign, i.e. gestational sac, double decidual sac sign, intradecidual sign, chorionic rim sign and yolk sac. Individual study estimates were plotted in summary receiver-operating characteristics curves and forest plots for examination of heterogeneity. The quality of included studies was assessed.

RESULTS

Seventeen studies including 2564 women were selected from 19 959 potential papers. Following meta-analysis, the presence of a gestational sac on ultrasound examination was found to predict an intrauterine pregnancy with a sensitivity of 52.8% (95% CI, 38.2-66.9%) and specificity of 97.6% (95% CI, 94.3-99.0%). The corresponding performance of the double decidual sac sign, intradecidual sign, chorionic rim sign and yolk sac were: 81.8% (95% CI, 68.1-90.4%) and 97.3% (95% CI, 76.1-99.8%); 66.1% (95% CI, 58.9-72.8%) and 100% (95% CI, 91.0-100%); 79.9% (95% CI, 73.0-85.7%) and 97.1% (95% CI, 89.9-99.6%); and 42.2% (95% CI, 27.7-57.9%) and 100% (95% CI, 54.1-100%), respectively.

CONCLUSION

Visualization of a gestational sac, double decidual sac sign, intradecidual sign or chorionic rim sign increases the probability of an intrauterine pregnancy but is not as accurate for diagnosis as the detection of the yolk sac. However, the findings were limited by the small number and poor quality of the studies included and heterogeneity in the index test and reference standard.

Imaging for acute pelvic pain in pregnancy

Acute pelvic pain in pregnancy presents diagnostic and therapeutic challenges. Standard imaging techniques need to be adapted to reduce harm to the foetus from X-rays because of their teratogenic and carcinogenic potential. Ultrasound remains the primary imaging investigation of the pregnant abdomen. Magnetic resonance imaging (MRI) has been shown to be useful in the diagnosis of gynaecological and obstetric problems during pregnancy and in the setting of acute abdomen during pregnancy. MRI overcomes some of the limitations of ultrasound, mainly the size of the gravid uterus. MRI poses theoretical risks to the foetus and care must be taken to minimise these with the avoidance of contrast agents. Teaching Points • Ultrasound and MRI are the preferred investigations for acute pelvic pain during pregnancy. • Ultrasound remains the primary imaging investigation because of availability and portability. • MRI helps differentiate causes of acute pelvic pain when ultrasound is inconclusive.

Reevaluation of discriminatory and threshold levels for serum β-hCG in early pregnancy

OBJECTIVES

To reevaluate both discriminatory and threshold levels associated with visualization of gestational sacs, yolk sacs, and fetal poles in patients presenting with vaginal bleeding, pain, or vaginal bleeding and pain in the first trimester of pregnancy using current ultrasonographic technology.

METHODS

We reviewed the records of patients with first-trimester vaginal bleeding, pelvic pain, or both who were evaluated with a serum β-hCG level and a transvaginal ultrasonogram within 6 hours of each other and had a known pregnancy outcome. Discriminatory and threshold β-hCG levels for visualization of a gestational sac, yolk sac, and fetal pole were identified for all ultimately viable pregnancies. Logistic regression was used to model the predicted probability of visualizing these structures as a function of β-hCG values using fractional polynomials.

RESULTS

Six hundred fifty-one pregnancies met inclusion criteria; 366 were viable. Discriminatory β-hCG levels at which structures would be predicted to be seen 99% of the time were 3,510 milli-international units/mL, 17,716 milli-international units/mL, and 47,685 milli-international units/mL for gestational sac, yolk sac, and fetal pole, respectively. In our population, threshold values for β-hCG levels at which these structures could be seen were 390 milli-international units/mL, 1,094 milli-international units/mL, and 1,394 milli-international units/mL, respectively.

CONCLUSIONS

Improvements in ultrasonographic technology have led to lower threshold β-hCG values for ultrasonographic visualization of early intrauterine gestational structures. However, discriminatory levels for serum β-hCG levels were higher than values currently used in practice.

LEVEL OF EVIDENCE

II.

ACR Appropriateness Criteria® Acute Pelvic Pain in the Reproductive Age Group

Premenopausal women who present with acute pelvic pain frequently pose a diagnostic dilemma, exhibiting nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. Diagnostic considerations encompass multiple organ systems, including obstetric, gynecologic, urologic, gastrointestinal, and vascular etiologies. The selection of imaging modality is determined by the clinically suspected differential diagnosis. Thus, a careful evaluation of such a patient should be performed and diagnostic considerations narrowed before a modality is chosen. Transvaginal and transabdominal pelvic sonography is the modality of choice when an obstetric or gynecologic abnormality is suspected, and computed tomography is more useful when gastrointestinal or genitourinary pathology is more likely. Magnetic resonance imaging, when available in the acute setting, is favored over computed tomography for assessing pregnant patients for nongynecologic etiologies because of the lack of ionizing radiation. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed every two years by a multidisciplinary expert panel. The guideline development and review include an extensive analysis of current medical literature from peer reviewed journals and the application of a well-established consensus methodology (modified Delphi) to rate the appropriateness of imaging and treatment procedures by the panel. In those instances where evidence is lacking or not definitive, expert opinion may be used to recommend imaging or treatment.

ACR Appropriateness Criteria on acute pelvic pain in the reproductive age group

Premenopausal women who present with acute pelvic pain frequently pose a diagnostic dilemma, exhibiting nonspecific signs and symptoms, the most common being nausea, vomiting, and leukocytosis. Diagnostic considerations encompass multiple organ systems, including obstetric, gynecologic, urologic, gastrointestinal, and vascular etiologies. The selection of imaging modality is determined by the clinically suspected differential diagnosis. Thus, a careful evaluation of such a patient should be performed and diagnostic considerations narrowed before a modality is chosen. Transvaginal and transabdominal pelvic sonography is the modality of choice when an obstetric or gynecologic abnormality is suspected, and computed tomography is more useful when gastrointestinal or genitourinary pathology is more likely. Magnetic resonance imaging, when available in the acute setting, is favored over computed tomography for assessing pregnant patients for nongynecologic etiologies because of the lack of ionizing radiation.

Imaging of pelvic pain in the first trimester of pregnancy

Pelvic pain during the first trimester of pregnancy can pose a challenge to the clinician. The noninvasive nature, safety, and reliability of ultrasonography make it the diagnostic method of choice for pregnant patients who have pelvic pain. Sonography provides information that allows for diagnosis of both pregnancy-related pain, such as a ruptured ectopic pregnancy, miscarriage, or threatened abortion; and may be useful in the diagnosis of pain unrelated to pregnancy, such as that seen in appendicitis and nephrolithiasis.

"Rule out ectopic": Asking the right questions, getting the right answers

Sonographic evaluation of the pregnant patient suspected of harboring an ectopic pregnancy (EP) helps determine patient management. Although clinicians typically ask sonologists to "rule out" EP in these patients, the sonologist actually must answer 3 questions: (1) Is there an intrauterine pregnancy (IUP)? (2) Is the possibility of normally developing IUP reliably excluded? (3) Are there sonographic findings that identify or increase the likelihood of an EP? Understanding the rationale behind these questions and the sonographic findings that help to answer these questions enables the sonologist to contribute meaningfully to the care of patients with possible EP. Beginning the sonographic examination with a limited transabdominal approach has value. An IUP can be confidently diagnosed by identification of an intradecidual sac exhibiting the double decidual sac sign, yolk sac, or embryo. When the serum beta human chorionic gonadothropin exceeds 2000 mIU/mL, a technically excellent sonographic examination should identify an intradecidual sac potentially representing an IUP. Even without directly visualizing a yolk sac or embryo in the adnexa, the presence of an extraovarian mass or hemoperitoneum strongly predicts the possibility of EP. An intraovarian mass with peripheral hypervascularity is more likely to represent the corpus luteum rather than an intraovarian EP. Cervical EP can be distinguished from the cervical phase of a spontaneous abortion in progress by either demonstrating fetal heart motion or persistence or enlargement of findings on short-interval follow-up. Absence of a myometrial mantle surrounding one edge of an IUP positioned at the fundus is suspicious for an interstitial EP.

Sonographic findings of transvaginal color Doppler ultrasound in ectopic pregnancy

PURPOSE

The objective of this study was to retrospectively assess whether the sonographic findings from transvaginal color Doppler ultrasound (TV-CDU) are helpful in the diagnosis of ectopic pregnancy.

METHODS

Thirty-four patients who received surgery for ectopic tubal pregnancies were preoperatively evaluated using TV-CDU. The presence or absence of color vascularity within the ectopic masses was examined. The relationship between the presence or absence of blood flow in the tubal mass and the corpus luteum cyst, or the serum β-hCG values, was evaluated.

RESULTS

Color vascularity within the adnexal mass was detected in 27 of 34 (79.4%) patients with ectopic pregnancies by TV-CDU. Color vascularity within the mass was observed in 18 of 24 (75.0%) patients with a questionable adnexal mass that had no obvious gestational sac in B-mode images. Moreover, color vascularity was seen in all four patients with a serum β-human chorionic gonadotropin (β-hCG) value of less than 500 mIU/ml. However, it was difficult to identify the blood flow of the adnexal mass in six of the nine (66.7%) patients with a corpus luteum cyst in the ipsilateral ovary. No relationship was observed between the serum β-hCG concentrations and the resistance indices, or the peak systolic velocity.

CONCLUSIONS

The detection of color vascularity by TV-CDU in patients with an ectopic pregnancy is helpful for diagnosis, especially for patients with either a questionable adnexal mass in B-mode images or lower serum β-hCG concentrations.

Ectopic pregnancy: a review

Ectopic pregnancy is a major clinical problem, occurring in 75,000 cases per year in the United States. With in vitro fertilization, embryo transfer, microsurgical techniques, and better early diagnosis, the rates of ectopic pregnancies have increased. Transvaginal sonography along with beta-human chorionic gonadotrophin monitoring are the standards for evaluation of suspected ectopic pregnancy. When ectopic pregnancy is present, transvaginal sonography most often demonstrates an adnexal finding directly related to the extra-uterine gestation itself, a hematoma caused by it, or both. Although tubal location is most common, it is important to recognize unusual locations of ectopic pregnancy such as isthmic, cervical, ovarian, and abdominal. Ultrasound is the mainstay of diagnosis, but magnetic resonance imaging can be helpful in unusual or complicated cases. Current therapeutic options for an ectopic pregnancy are expectant management, systemic methotrexate injections, sonographically guided minimal invasive treatment, and surgery. This review encompasses diagnosis, treatment, and management of ectopic pregnancy.

Effect of transvaginal sonography on the use of invasive procedures for evaluating patients with a clinical diagnosis of ectopic pregnancy

PURPOSE

Our purpose was to determine the effect of transvaginal sonography (TVS) on the diagnostic evaluation of patients with suspected ectopic pregnancy (EP). Specifically, we wished to determine what effect TVS had on the use of invasive procedures.

METHODS

This was a retrospective review of the medical records of 290 patients with a surgically documented diagnosis of EP. It included 147 consecutive patients from the era of use of suprapubic sonography (SPS) (1982-1987) and 143 consecutive patients from the era of use of TVS (1987-1995). We compared the percentages of patients who had undergone sonographic examinations, the rates of use of the invasive procedures dilatation and curettage (D&C) and diagnostic laparoscopy (DL), time from presentation to diagnosis, necessity for transfusion, status of EP at surgery, and various other characteristics of the patients (eg, demographics, serum level of beta human chorionic gonadotropin, and presenting symptoms).

RESULTS

In the SPS era, 46.9% of the patients had undergone sonography, compared with 78.3% in the TVS era (p = 0.001). Sonographic sensitivity was 60.9% in the SPS era and 93.8% in the TVS era (p = 0.001). D&C was performed in 53.1% and DL in 76.2% of patients in the SPS era, compared with 14.0% and 30.8%, respectively, in the TVS era (p = 0.001). In the last full year of the study, only 9% of the patients had undergone D&C and 9%, DL. The overall time from presentation to diagnosis significantly decreased from 45.6 hours in the SPS era to 16.8 hours in the TVS era (p = 0.002). We found no significant difference between the 2 eras in the need for transfusion and the percentage of ruptured EPs at surgery (p > 0.05).

CONCLUSIONS

The introduction of TVS has had an important effect on the evaluation of patients with EP by nearly eliminating the need for D&C and DL and permitting clinicians to take a more conservative approach to managing EP.

Subclassification of indeterminate pelvic ultrasonography: prospective evaluation of the risk of ectopic pregnancy

STUDY OBJECTIVE

We sought to determine the frequency of ectopic pregnancy among subclasses of indeterminate ultrasonographic examinations.

METHODS

A prospective observational study was performed from January 1, 1995, to August 31, 2000, on consecutive emergency department patients in the first trimester of pregnancy with a chief complaint of abdominal pain or vaginal bleeding and who had an indeterminate transvaginal ultrasonographic examination at the time of the ED visit. Patients were excluded if lost to follow-up. Ultrasonographic examinations were subclassified into 5 groups (ie, empty uterus, nonspecific fluid, echogenic material, abnormal sac, normal sac) on the basis of a previously published classification system. Patients were followed up until the diagnosis of ectopic pregnancy was either confirmed or excluded. The frequencies of ectopic pregnancy, along with 95% confidence intervals (CIs), were calculated for each of the subclasses. The relative risk of ectopic pregnancy was calculated when appropriate.

RESULTS

Seven hundred eighty patients with indeterminate ultrasonographic examinations were identified. One hundred forty-five were lost to follow-up, and therefore, 635 were enrolled. The frequency of ectopic pregnancy for each subclass is as follows: empty uterus, 36 of 259 (13.9%; 95% CI 10.1% to 18.5%); nonspecific fluid, 6 of 127 (4.7%; 95% CI 1.9% to 9.6%); echogenic material, 4 of 93 (4.3%; 95% CI 1.4% to 10.5%); abnormal sac, 0 of 103 (0%; 95% CI 0.0% to 2.9%); and normal sac, 0 of 53 (0%; 95% CI 0.0% to 5.5%). The relative risk of ectopic pregnancy in patients with an empty uterus versus in those without an empty uterus was 5.2 (95% CI 2.6 to 10.2).

CONCLUSION

In our sample, patients with an empty uterus at ultrasonography had the highest frequency of ectopic pregnancy, with a relative risk of ectopic pregnancy 5 times greater than that of the other 4 subclasses.

Isolated fluid in the cul-de-sac: how well does it predict ectopic pregnancy?

We examined the risk of ectopic pregnancy among patients with isolated abnormal cul-de-sac fluid at transvaginal ultrasound. We conducted a retrospective cohort study of all ED patients presenting January 1995 to August 1999 with abdominal pain or vaginal bleeding and a positive beta-hCG test. The risk of ectopic pregnancy in patients with a moderate volume of anechoic fluid was compared with those with either a large volume of anechoic fluid or any echogenic fluid. Ectopic pregnancy was diagnosed in 16/38: 42%(95% CI 26%-59%) of patients with isolated cul-de-sac fluid, 5/23: 22% (95% CI 7%-42%) of patients with moderate amount of anechoic fluid, and 11/15: 73% (95% CI 45%-92%) of patients with a large volume of fluid or any echogenic fluid. These differences were significant (P =.005). Patients with isolated abnormal cul-de-sac fluid are at moderate risk for ectopic pregnancy. The risk increases if the fluid is echogenic or the volume is large.

Expectant treatment of ectopic pregnancies: clinical and sonographic predictors

OBJECTIVE

We identified the potential clinical and sonographic predictors of the spontaneous resolution of ectopic pregnancies.

SUBJECTS AND METHODS

We performed a prospective study of 78 consecutive patients with a transvaginal sonographic diagnosis of ectopic pregnancy who had either two consecutive quantitative measurements of their beta subunit of human chorionic gonadotropin (beta-hCG) more than 24 hrs apart or an embryo with a heart beat. We evaluated the patient's age, time from the last menstrual period, beta-hCG level, size of ectopic pregnancy, presence of a gestational sac or embryonic elements, vascularity on color Doppler sonography, peak systolic velocity, and resistive index of ectopic pregnancy at the time of presentation as potential independent predictors of the final outcome. Logistic regression was performed to identify the independent predictors.

RESULTS

Forty-six patients had declining beta-hCG levels, and 32 ectopic pregnancies showed an embryo with a heart beat or had steady or rising beta-hCG levels. Univariate analysis indicated that a longer time from the last menstrual period (older ectopic pregnancies), lower beta-hCG levels, and the absence of gestational sac are statistically more significantly seen in ectopic pregnancies with declining beta-hCG levels (p < 0.05). Resistive index of ectopic pregnancy reached borderline significance (p = 0.05). In a multiple logistic model, the same variables were independent predictors of outcome (p < 0.05). Resistive index was also a predictor (p = 0.09).

CONCLUSION

Longer times from the last menstrual period, lower beta-hCG levels, absence of gestational sacs, and higher resistive indexes of ectopic pregnancy at the time of presentation appear to be independent predictors of the spontaneous resolution of ectopic pregnancy.

The roles of clinical assessment, human chorionic gonadotropin assays, and ultrasonography in medical abortion practice

The clinical assessment of patients who request early medical abortion includes confirmation of the diagnosis of pregnancy and estimation of gestational age. Accurate gestational dating is essential, because the efficacies of medical abortion regimens decline as pregnancy advances. Whereas medical abortion researchers in the United States have relied on routine ultrasonography for gestational dating, abortion providers experienced with mifepristone and prostaglandin regimens outside the United States have reported high efficacy and safety primarily with clinical dating parameters. Diligent follow-up of patients allows clinicians to confirm that complete abortion has occurred without complications. In cases of uncertain outcome or suspected ectopic pregnancy, transvaginal ultrasonography and beta-human chorionic gonadotropin assays can assist in prompt diagnosis and management. As medical abortion with mifepristone and misoprostol becomes more prevalent in the United States, studies will be needed to further evaluate the effects of these modalities on medical abortion outcomes.

Levels of vascular endothelial growth factor are elevated in patients with ectopic pregnancy: is this a novel marker?

OBJECTIVE

To determine serum levels of vascular endothelial growth factor (VEGF) and evaluate their capacity to serve as a marker for the diagnosis of ectopic pregnancy (EP).

DESIGN

Prospective, case-controlled study.

SETTING

A tertiary care center.

PATIENT(S)

Twenty women with EP, 10 women with normal intrauterine pregnancy, and 10 women with abnormal intrauterine pregnancy, all at comparable stages of gestation.

INTERVENTION(S)

Serum samples were obtained from all women.

MAIN OUTCOME MEASURE(S)

All samples were analyzed for VEGF, progesterone, and beta-hCG by specific methods.

RESULT(S)

Women with EP had higher serum levels of VEGF than women with normal intrauterine pregnancy and women with abnormal intrauterine pregnancy (median levels, 226.8 pg/mL, 24.4 pg/mL, and 59.4 pg/mL, respectively). With a cutoff level of 200 pg/mL, serum VEGF could distinguish intrauterine from extrauterine pregnancy with a sensitivity of 60%, specificity of 90%, and positive predictive value of 86%.

CONCLUSION(S)

The increased serum VEGF levels in women with EP may facilitate this challenging diagnosis and reduce maternal morbidity and mortality.

Implementation of probabilistic decision rules improves the predictive values of algorithms in the diagnostic management of ectopic pregnancy

Current algorithms for the diagnosis of ectopic pregnancy do not take into account the heterogeneity in patient profiles. Such heterogeneity can lead to differences in the pre-test probability of ectopic pregnancy. In patients with clinical symptoms, for example, the probability of presence of an ectopic pregnancy is higher than in symptom-free patients. Any additional tests should then be interpreted differently, depending on the pre-test probability. We present a diagnostic algorithm that uses probabilistic decision rules for the evaluation of women with suspected ectopic pregnancy with flexible cut-off levels for test positivity We compare it with a general algorithm that uses fixed cut-off levels. Fictitious cohorts, varying in prevalence of ectopic pregnancy were put together, using data obtained from a cohort of >800 women with suspected ectopic pregnancy. In the inflexible algorithm, ectopic pregnancy was diagnosed whenever it could be visualized at transvaginal sonography, or where serum human chorionic gonadotrophin (HCG) exceeded a rigid cut-off level; ectopic pregnancy was rejected if an intrauterine pregnancy was seen or when serum HCG decreased. In the flexible algorithm, a post-test probability was obtained after each test, using pre-test probabilities and test-based likelihood ratios. Ectopic pregnancy was diagnosed whenever the post-test probability for ectopic pregnancy exceeded 95%, whereas this diagnosis was rejected if the calculated post-test probability fell below 1%. For both algorithms, sensitivity and specificity as well as predictive values were calculated. At each prevalence, the inflexible algorithm was associated with a sensitivity of 93% and a specificity of 97%. In contrast, the sensitivity and specificity of the flexible, individualized algorithm depended on the prevalence of ectopic pregnancy. Consequently, predictive values varied strongly when the inflexible algorithm was used, whereas they were much more stable after using the flexible algorithm. For five possible valuations of false positive and false negative diagnoses, the flexible algorithm reduced the expected disutility, compared with the inflexible algorithm. It is concluded that clinicians should incorporate probabilistic decision rules in algorithms used for the diagnosis of ectopic pregnancy.

History and physical examination to estimate the risk of ectopic pregnancy: validation of a clinical prediction model

STUDY OBJECTIVE

To prospectively validate a clinical prediction model for ectopic pregnancy (EP).

METHODS

Prospective cohort with 14-month derivation and 12-month validation phases. All hemodynamically stable, first-trimester patients with abdominal pain or vaginal bleeding who presented to a military teaching hospital emergency department underwent follow-up until an outcome of intrauterine pregnancy (IUP) or EP was established. Patients were separated into the high-risk group, defined as having either peritoneal signs or definite cervical motion tenderness; intermediate-risk group, defined as the presence of pain or tenderness, other than midline cramping, plus absence of fetal heart tones, and absence of tissue visible at the cervical os; and low-risk group (neither high- nor intermediate-risk) using recursive partitioning.

RESULTS

Summarizing both phases, 915 patients had 845 (93%) IUPs and 70 (7.6%) EPs, with 18 (1.9%) lost to follow-up. The clinical prediction model classified 75 (8.2%) into the high-risk group (sensitivity 31%, 95% confidence interval [CI] 21% to 44%; specificity 94%, 95% CI 92% to 95%); and 644 (70%) in the intermediate-risk group (sensitivity 98%, 95% CI 89% to 100%; specificity 25%, 95% CI 22% to 29%). The remaining 196 (21%) patients who met neither high-risk nor intermediate-risk criteria were classified into the low-risk group. On the basis of EP prevalence of 7.7%, the risk of EP was less than 1% (95% CI 0% to 3%) for the low-risk group, 7% (95% CI 5% to 10%) for the intermediate-risk group, and 29% (95% CI 19% to 41%) for the high-risk group.

CONCLUSION

This clinical prediction model is useful for estimating the risk of EP in first-trimester patients, particularly when ancillary testing is equivocal or not readily available.

Serum human chorionic gonadotropin measurement in the diagnosis of ectopic pregnancy when transvaginal sonography is inconclusive

OBJECTIVE

To assess the accuracy of initial and repeated serum hCG measurements in the diagnosis of ectopic pregnancy (EP) in patients in whom transvaginal sonography is inconclusive and to evaluate whether patient characteristics influence the accuracy of serum hCG measurements.

DESIGN

Prospective study.

SETTING

Two large teaching hospitals in Amsterdam, the Netherlands.

PATIENT(S)

Three hundred fifty-four consecutively seen pregnant patients with suspected EP and inconclusive transvaginal sonographic findings.

INTERVENTION(S)

Serum hCG measurements.

MAIN OUTCOME MEASURE(S)

The performance of repeated serum hCG measurements in the diagnosis of EP was evaluated through the analysis of receiver operating characteristic curves.

RESULT(S)

Initial serum hCG measurements were more diagnostic in conjunction with sonographic evidence of an ectopic mass or fluid in the pouch of Douglas than in the absence of sonographic abnormalities. On repeated measurement, the course of the serum hCG concentration provided more diagnostic information than did the absolute serum hCG concentration 2 and 4 days after the start of the diagnostic process.

CONCLUSION(S)

The interpretation of serum hCG measurements should depend on additional findings at transvaginal sonography. A cutoff level of 1,500 IU/L is recommended for patients with an ectopic mass or fluid in the pouch of Douglas; in patients without these findings, the cutoff level should be at least 2,000 IU/L. Four days after the start of the diagnostic process, any rise in the serum hCG concentration makes the diagnosis of EP very likely.

Derivation of a clinical prediction model for the emergency department diagnosis of ectopic pregnancy

OBJECTIVE

To derive a clinical prediction model for estimating the pretest probability of ectopic pregnancy in ED patients with first-trimester abdominal pain or vaginal bleeding.

METHODS

All hemodynamically stable first-trimester patients presenting to the ED of a tertiary care military teaching hospital over a 14-month period with a chief complaint of abdominal pain and/or vaginal bleeding had clinical data coded prior to determining outcome. They were then followed longitudinally until a criterion standard pregnancy outcome was established.

RESULTS

Of the 486 patients enrolled, 280 (58%) had viable intrauterine pregnancies, 167 (34%) had nonviable intrauterine pregnancies, and 39 (8%) had ectopic pregnancies. Using a recursive partitioning model, a high-risk group was derived (that was separated from intermediate and low-risk groups), consisting of patients with abdominal peritoneal signs or definite cervical motion tenderness, with a sensitivity of 31% (95% CI: 17-48%), a specificity of 93% (95% CI: 90-95%), a positive likelihood ratio of 4.3, and a negative likelihood ratio of 0.74. A low-risk group, consisting of patients with either fetal heart tones or tissue at the cervical os, or the absence of pain other than midline menstrual-like cramping and lacking any pelvic tenderness, was differentiated from an intermediate-risk group, with a sensitivity of 96% (95% CI: 81-100%), a specificity of 22% (95% CI: 18-26%), a positive likelihood ratio of 1.2, and a negative likelihood ratio of 0.17.

CONCLUSION

A clinical prediction model for estimating the probability of ectopic pregnancy in ED patients has been derived. It may prove to have practical clinical application for estimating pretest probability of ectopic pregnancy as well as assisting in medical decision making when laboratory and ultrasonographic findings are nondiagnostic. Clinical application should await prospective validation in an independent sample.

Subclassification of indeterminate pelvic ultrasonograms: stratifying the risk of ectopic pregnancy

OBJECTIVE

To determine whether the subclassification of indeterminate ultrasound readings can identify patients who are at high, intermediate, or low risk for ectopic pregnancy.

METHODS

A retrospective review was made of consecutive ED patients presenting to an urban teaching hospital from August 1991 to December 1994 with abdominal pain and/or vaginal bleeding and a positive beta-hCG. Patients who had transvaginal ultrasonograms obtained during the ED visit that were read as indeterminate (no extrauterine findings of ectopic pregnancy and no intrauterine fetal pole or yolk sac) were eligible. Ultrasonograms were subclassified into 5 groups (empty uterus, nonspecific intrauterine fluid, echogenic debris within endometrial cavity, abnormal sac, normal sac) based on predetermined criteria. Patients were excluded if the final diagnosis could not be definitively determined.

RESULTS

248 patients were identified. 20 patients were excluded because a final diagnosis could not be determined. Patients with an empty uterus [25/94 = 27% (95% CI 18-36%)] had the highest frequency of ectopic pregnancy. Patients with nonspecific intrauterine fluid collections [4/30 = 13% (95% CI 4-31%)] had the next highest frequency of ectopic pregnancy. Patients with intrauterine echogenic debris [2/39 = 5% (95% CI 1-11%)], abnormal sacs [1/36 = 3% (95% CI 1-9%)], or normal-appearing sacs [0/29 = 0% (95% CI 0-8%)] had low frequencies of ectopic pregnancy.

CONCLUSION

Subclassification of indeterminate ultrasound readings identifies patients at high, intermediate, or low risk for ectopic pregnancy and should improve the diagnostic accuracy of ultrasonography in patients at risk for ectopic pregnancy.

The ability of a single serum progesterone value to identify abnormal pregnancies in patients with beta-human chorionic gonadotropin values less than 1,000 mIU/mL

OBJECTIVE

To determine the test performance of a single serum progesterone value <5.0 ng/mL for detecting ectopic pregnancy or other abnormal pregnancies in symptomatic ED patients with beta-hCG levels <1,000 mIU/mL.

METHODS

A prospective study of progesterone levels was performed in consecutive ED patients presenting to an urban teaching hospital from December 1995 to March 1997 with abdominal pain and/or vaginal bleeding, a positive qualitative beta-hCG, and a quantitative beta-hCG value <1,000 mIU/mL. Patients were excluded if they were status-post a dilatation and evacuation procedure, had insufficient serum to run the progesterone assays, or were lost to follow-up. Progesterone values were measured from the original beta-hCG sample. Final patient diagnosis was abstracted from hospital records.

RESULTS

127 patients met eligibility criteria. 39 patients were excluded, leaving a total of 88 enrolled patients. 76 patients with abnormal pregnancies were identified [9 ectopic pregnancies, 62 abnormal intrauterine pregnancies (IUPs), 5 abnormal IUPs vs ectopic pregnancies], 71 of whom had progesterone values <5.0 ng/mL [sensitivity 71/76 (94%), 95% CI 86-98%]. 12 patients with normal pregnancies were identified, all of whom had progesterone values > or =5.0 ng/mL [specificity 12/12 (100%), 95% CI 78-100%].

CONCLUSION

A single progesterone value <5.0 ng/mL has high sensitivity and specificity in detecting abnormal pregnancy in symptomatic ED patients with beta-hCG values <1,000 mIU/mL.

Abdominal pain during pregnancy

In evaluating the pregnant patient with abdominal pain, the physician is presented with a wide range of diagnostic possibilities, including disorders that can occur in nonpregnant individuals and disorders that are unique to pregnancy. The development of modern laboratory testing methods and diagnostic imaging techniques has led to a decline in the morbidity and mortality from many of these disorders. With an understanding of the physiologic changes occurring during pregnancy, a careful history and physical examination, and judicious use of laboratory tests and imaging studies, the physician should be able to determine the cause of the patient's pain in the great majority of cases and, in the words of Babler, avoid "the mortality of delay."

Transvaginal ultrasound in patients with low beta-human chorionic gonadotropin values: how often is the study diagnostic?

STUDY OBJECTIVE

To determine how often pelvic ultrasonography diagnoses or excludes ectopic pregnancy (EP) in patients who present with abdominal pain or vaginal bleeding and a beta-human chorionic gonadotropin (beta-hCG) level lower than 1,000 mIU/mL.

METHODS

This was a retrospective chart review of all patients who presented to the ED of an urban teaching hospital from August 1991 through July 1995 with lower abdominal pain or bleeding, a positive beta-hCG assay, and a quantitative beta-hCG value lower than 1,000 mIU/mL in whom pelvic transvaginal ultrasound was performed within 24 hours of the ED visit. Ultrasound procedures were performed in the radiology department by ultrasound technicians under the direct supervision of an attending radiologist or resident in radiology. Patients were excluded if they had recently delivered or undergone dilatation and curettage, had had a previous ultrasound examination during this pregnancy, had decreasing beta-hCG values, or were lost to follow-up before a definitive diagnosis was made.

RESULTS

: A total of 111 patients met the inclusion criteria; 19 patients (17%; 95% confidence interval [CI], 10% to 24%) had diagnostic ultrasound findings. Of these, 10 findings were diagnostic of intrauterine pregnancy and 9 for EP. The beta-hCG values for the patients with diagnostic examinations ranged from 47 to 995 mIU/mL. Twenty-three study patients ultimately received a diagnosis of EP; of these, 9 (39%; CI, 19% to 59%) had a diagnostic initial ultrasound study. Five of the nine had beta-hCG values lower than 500 mIU/mL.

CONCLUSION

Approximately one third of women with EP who present with beta-hCG values lower than 1,000 mIU/mL were identified with an urgent transvaginal ultrasound examination performed by trained ultrasound technicians. Clinicians should consider the use of pelvic ultrasound in patients with suspected EP, regardless of their beta-hCG values, particularly at institutions where ultrasound is readily available.

Transvaginal sonographic findings of chronic ectopic pregnancy

Chronic ectopic pregnancy is not precisely defined in gynecologic and sonographic texts. The diagnosis of this enigmatic clinical condition is frequently not made until laparotomy. In the present retrospective study, we evaluated the transvaginal sonographic findings of cases who were diagnosed as chronic ectopic pregnancy intraoperatively and/or postoperatively. The incidence of chronic ectopic pregnancy was found to be 20.3% (62/305) of all ectopic pregnancies. Of these 62 cases, 55 had transvaginal sonographic examination. On transvaginal sonographic examination, all 55 cases of chronic ectopic pregnancy had a complex adnexal mass with an empty uterus and only 18 (32.7%) had simple fluid in the pelvis/cul-de-sac. In the majority of cases (82.7%, n = 48), there was a non-homogeneous echo pattern within the adnexal mass. Of 55 cases, 30 had color Doppler flow examination, of whom none had color Doppler flow imaging on the wall of the mass or within the mass. There was a negative quantitative beta human chorionic gonadotropin (beta-hCG) assay (i.e. 0 mIU/ml) in only 4 cases. Based on this study, we concluded that chronic ectopic pregnancy is not a rare clinical entity and should be considered in differential diagnosis among patients presenting with an adnexal mass and an overt clinical picture. Transvaginal sonography is sensitive in diagnosing chronic ectopic pregnancy, but not specific. The combined use of transvaginal ultrasonography and beta-hCG assay increases diagnostic accuracy. However, it should be kept in mind that a negative beta-hCG value does not rule out chronic ectopic pregnancy.

Emergency department pregnancy testing

The rapid and accurate diagnosis of pregnancy is a necessity for emergency physicians. Physicians of the 1990s are fortunate to have available inexpensive, rapid pregnancy tests with virtually no false positives or negatives. The current basis of endocrine pregnancy tests is detection of Human Chorionic Gonadotrophin (HCG) in the serum or urine. The single HCG tests in combination with ultrasound, as well as serial HCGs, are also useful in the diagnosis of ectopic pregnancy. Serum progesterone, although at present not widely used in the emergency department, shows great promise as a test useful in the often difficult task of distinguishing ectopic and abnormal pregnancies from viable intrauterine pregnancies.

Contraception and the risk of ectopic pregnancy: a meta-analysis

The current knowledge of the association between contraceptive methods and the risk of ectopic pregnancy was evaluated by means of a meta-analysis. Case-control and cohort studies published between 1978 and 1994 in English, French, German and Dutch were retrieved by a search in Medline, a hand-search on recent medical journals and cross-references. Papers reporting on the association between contraceptives and ectopic pregnancy were judged according to predefined entrance criteria concerning selection of control groups, and retractability of raw data enabling the calculation of crude odds ratios. Common Odds Ratios (COR) and 95% confidence intervals were calculated if homogeneity was not rejected. Twelve case-control studies and one cohort study were detected. CORs could be calculated for current and past use of oral contraceptives, past IUCD use and tubal sterilization. All assessed contraceptives protect against ectopic pregnancy. Women becoming pregnant after sterilization or while currently using an IUCD are at an increased risk. The IUCD is the only contraceptive method associated with an increased risk after discontinuation of its use.

Early Pregnancy and Its Normal Measurement Parameters Practical Mnemonic "Rule of 2"

With the intent of helping in the memorization of information, we present an arrangement of data on hormone levels, gestational sac, yolk sac, and embryo in early pregnancy. When pertinent, we compare abdominal with endovaginal scanning parameters.

Ultrasonographic examination by emergency physicians of patients at risk for ectopic pregnancy

OBJECTIVE

To evaluate a diagnostic protocol that includes the early use of endovaginal sonography (EVS) by emergency physicians of patients at risk for ectopic pregnancy.

METHODS

During this prospective study, pregnant patients > or = 18 years old and at risk for ectopic pregnancy were assessed. Emergency physicians who had completed a training program performed EVS on a convenience sample of eligible women. Clinical disposition was based on predetermined clinical, laboratory, and ultrasonographic criteria. The EVS examinations were reviewed on video by a gynecologist whose interpretation was correlated with the emergency physician EVS readings and with the final clinical diagnoses. Quantitative serum beta-human chorionic gonadotropin (beta hCG) levels were determined for patients who had no definite intrauterine pregnancy (IUP) on EVS.

RESULTS

Of 152 patients studied during a 12-month period, four were lost to follow-up. Emergency physician ultrasonographic diagnoses included: definite IUP, 87/148 (59%); probable abnormal IUP, 17/148 (11%); definite ectopic pregnancy, 3/148 (2%); and no definite IUP, 41/148 (28%). The gynecologist agreed with 93% of the initial interpretations. Twelve of 16 patients who had the final diagnosis of ectopic pregnancy were admitted from the ED with this diagnosis. The ultrasonographic diagnosis of the other four was no definite IUP, and no mass or free fluid. For the latter four patients, the presenting serum beta hCG level was < 2,000 mIU/mL (First International Reference Preparation). They were diagnosed as having ectopic pregnancy after serial outpatient EVS and beta hCG measurements.

CONCLUSIONS

The application of EVS to emergency practice appears promising. Emergency physicians trained in its use and who apply this diagnostic tool in conjunction with a defined protocol can stratify the risk of patients who have the potential for ectopic pregnancy.

Relation between gestational sac diameter, crown-rump length, and maternal serum estradiol, progesterone, and prolactin levels in early pregnancy

In 152 patients with an early pregnancy which was subsequently normal, we measured the maternal serum levels of estradiol (E2), progesterone (P4) and prolactin (PRL) as well as the diameter of gestational sac (GS) and the crown-rump length (CRL) of the embryo by transvaginal ultrasonography. The maternal serum level of E2 had the closest statistically significant correlation with both the GS diameter (r = 0.769, P < 0.01) and the CRL (r = 0.736, P < 0.001). P4 and PRL concentrations showed less correlation with embryo development.

The screening of embryonic viability in early asymptomatic pregnancy by a single endosonographic scan associated with plasma human chorionic gonadotropin determination

PURPOSE

Our purpose was to assess, with a prospective study with random assignment of the day of the first evaluation, whether a single transvaginal ultrasonographic evaluation together with the determination of plasma hCG levels could be used to screen embryonic viability in early asymptomatic pregnancy.

METHODS

In 260 pregnant women observed from January 1991 to November 1993 with spontaneous pregnancies where the exact date of ovulation was known, a single transvaginal ultrasonographic measurement of gestational sac with determination of plasma hCG levels, transformed to their natural logarithm (lnhCG), was performed. An abnormal result was defined as a value of lnhCG per mean gestational sac below the 95% lower confidence limit of the viable pregnancy group.

RESULTS

The sensitivity was 31%, with a specificity of 97%.

CONCLUSION

The study demonstrates that this method has a poor predictive capacity to distinguish viable pregnancy from nonviable pregnancy with a kappa value less than 0.4.

The discriminatory human chorionic gonadotropin zone for endovaginal sonography: a prospective, randomized study

OBJECTIVE

To determine the probability of detecting the gestational sac of a normal intrauterine pregnancy by vaginal ultrasound at different gestational ages and serum hCG concentrations.

DESIGN

Prospective, randomized study.

SETTING

Pregnant human volunteers in a university-based clinical research environment.

PATIENTS

Women with viable pregnancies who conceived spontaneously or after ovulation induction.

INTERVENTIONS

Vaginal ultrasound and serum hCG determinations were performed between 20 and 30 days after conception. The timing of the tests was determined randomly.

MAIN OUTCOME MEASURE

Detection of gestational sac.

RESULTS

The probability of detecting a gestational sac increased significantly with both gestational age and serum hCG concentration, but the regression on gestational age fitted the data much better than the regression on loge (hCG). The probability of detecting a sac was similar in multiple and singleton pregnancies of the same gestational age but, for a given hCG concentration, the probability of detecting a sac was lower for multiple than for singleton pregnancies because multiple gestations were associated with higher serum hCG concentrations than singleton pregnancies of the same gestational age.

CONCLUSION

If it is known, gestational age rather than the serum hCG concentration should be used to determine whether the gestational sac of an intrauterine pregnancy should be detectable by vaginal ultrasound. Failure to image a gestational sac > or = 24 days after conception is presumptive evidence of an ectopic pregnancy. Reliance on serum hCG rather than gestational age may lead to an erroneous diagnosis of ectopic pregnancy in women with multiple pregnancies.