Imaging the Uterus in Placenta Accreta Spectrum Disorder.

Antenatal diagnosis of placenta accreta spectrum (PAS) improves maternal and neonatal outcomes by allowing for multidisciplinary planning and preparedness. Ultrasound is the primary imaging tool. Simplification and standardization of placental evaluation and reporting terminology allows improved communication and understanding between teams. Prior to 10 weeks of gestation, gestational sac position and least myometrial thickness surrounding the gestational sac help PAS diagnosis very early in pregnancy. Late first-, second-, and third-trimester evaluation includes comprehensive evaluation of the placenta, transabdominal and transvaginal with partially full maternal urinary bladder, and by color Doppler. Subsequently, the sonologist should indicate whether the evaluation was optimal or suboptimal; the level of suspicion as low, moderate, or high; and the extent as focal, global, or extending beyond the uterus. Other complementary imaging modalities such as 3D-power Doppler ultrasound, magnetic resonance imaging (MRI), and vascular topography mapping strive to improve antenatal placental evaluation but remain investigational at present. KEY POINTS: · Antenatal imaging, primarily using ultrasound with partially full maternal urinary bladder, is an essential means of evaluation of those at risk for PAS.. · Simplification and standardization of placental evaluation and reporting will allow improved communication between the multidisciplinary teams.. · Gestational sac location prior to 10 weeks of gestation and four markers after that (placental lacunae and echostructure, myometrial thinning, hypoechoic zone with or without bulging between placenta and myometrium, and increased flow on color Doppler)..

Special Report of the Society for Maternal-Fetal Medicine Placenta Accreta Spectrum Ultrasound Marker Task Force: Consensus on definition of markers and approach to the ultrasound examination in pregnancies at risk for placenta accreta spectrum.

Placenta accreta spectrum includes the full range of abnormal placental attachment to the uterus or other structures, encompassing placenta accreta, placenta increta, placenta percreta, morbidly adherent placenta, and invasive placentation. The incidence of placenta accreta spectrum has increased in recent years, largely driven by increasing rates of cesarean delivery. Prenatal detection of placenta accreta spectrum is primarily made by ultrasound and is important to reduce maternal morbidity associated with the condition. Despite a large body of research on various placenta accreta spectrum ultrasound markers and their screening performance, inconsistencies in the literature persist. In response to the need for standardizing the definitions of placenta accreta spectrum markers and the approach to the ultrasound examination, the Society for Maternal-Fetal Medicine convened a task force with representatives from the American Institute of Ultrasound in Medicine, the American College of Obstetricians and Gynecologists, the American College of Radiology, the International Society of Ultrasound in Obstetrics and Gynecology, the Society for Radiologists in Ultrasound, the American Registry for Diagnostic Medical Sonography, and the Gottesfeld-Hohler Memorial Ultrasound Foundation. The goals of the task force were to assess placenta accreta spectrum sonographic markers on the basis of available data and expert consensus, provide a standardized approach to the prenatal ultrasound evaluation of the uterus and placenta in pregnancies at risk of placenta accreta spectrum, and identify research gaps in the field. This manuscript provides information on the Placenta Accreta Spectrum Task Force process and findings.

Assessment of the Placental Cord Insertion Using 3-Dimensional Ultrasound at the Time of the Structural Fetal Survey.

OBJECTIVES: The influence of placental morphologic characteristics on pregnancy outcomes is poorly understood. Our objective was to evaluate the relationship of the distance of the placental cord insertion from the placental edge (PCI-D) with associated placental characteristics as well as birth outcomes. METHODS: We performed a retrospective cohort study of nulliparous women with singleton gestations undergoing obstetric ultrasound examinations between 14 and 23 weeks' gestation with a cervical length of greater than 3.0 cm who delivered between 24 and 42 weeks. A 3-dimensional volume of the placenta was evaluated. The PCI-D was obtained with Virtual Organ computer-aided analysis software (GE Healthcare, Milwaukee, WI). Generalized linear regression and generalized additive models were fitted to explore the associations between the PCI-D in relation to demographic and clinical characteristics. RESULTS: A total of 216 pregnancies were included in the analysis. The PCI-D did not correlate with maternal age, gestational age at delivery, mode of delivery, or 5-minute Apgar score. Although not statistically significant, the birth weight z score (P = .09) was associated with a longer PCI-D, and gravidity was associated with a shorter PCI-D (P = .10). A low-lying placenta or placenta previa was associated with a longer PCI-D (P = .03). CONCLUSIONS: The PCI-D is associated with a low placental position in the second trimester. These data are helpful for understanding placental development. The PCI-D may be associated with pregnancy-related factors such as birth weight and multigravidity. More research is required to evaluate the effects of pregnancy-related factors on the PCI-D and the effect of the PCI-D on pregnancy outcomes.

Consider ultrasound first for imaging the female pelvis.

Ultrasound technology has evolved dramatically in recent years and now includes applications such as 3-dimensional volume imaging, real-time evaluation of pelvic organs (simultaneous with the physical examination), and Doppler blood flow mapping without the need for contrast, which makes ultrasound imaging unique for imaging the female pelvis. Among the many cross-sectional imaging techniques, we should use the most informative, less invasive, and less expensive modality to avoid radiation when possible. Hence, ultrasound imaging should be the first imaging modality used in women with pelvic symptoms.

Detection of fetal structural anomalies in a basic first-trimester screening program for aneuploidy.

OBJECTIVES: The purpose of this study was to determine whether first-trimester aneuploidy screening sonography initially performed by credentialed sonographers was useful for detecting fetal anomalies between 11 and 14 weeks' gestation. METHODS: We conducted a retrospective cohort study of consecutive patients referred to a private ultrasound facility between January 1, 2008, and June 30, 2012, for measurement of the nuchal translucency (NT) and crown-rump length as part of a screening protocol for aneuploidy. Patients were included if there was at least 1 live fetus with a crown-rump length between 34 and 84 mm. No specific anatomic imaging protocol was followed. The presence of anomalies was based on the sonographic report and review of the medical record. The absence of anomalies was based on the report from the anatomic survey. Anomalies were categorized as lethal, major, and minor. The anomaly category and gestational age at diagnosis (≤14 versus >14 weeks) were compared. RESULTS: An NT scan was performed on 9692 fetuses. Anatomic surveys were done on 9077 (93.7%) of these fetuses at a mean of 18 weeks' gestation. Anomalies were detected in 180 fetuses (1.8%): 50 (0.5%) at the NT scan and 130 (1.3%) at the anatomic scan. Overall, 46 of 111 fetuses (41.4%) with major or lethal anomalies were detected at the NT scan. Two suspected abnormalities at the NT scan were not present at the anatomic scan. CONCLUSIONS: First-trimester aneuploidy screening sonography initially performed by credentialed sonographers can identify a substantial proportion of major and lethal anomalies.

What is the importance of second-trimester "soft markers" for trisomy 21 after an 11- to 14-week aneuploidy screening scan?

OBJECTIVES: The purpose of this study was to evaluate the importance of second-trimester "soft markers" for trisomy 21 after an 11- to 14-week aneuploidy screening scan. METHODS: We conducted a retrospective cohort study of consecutive patients referred for measurement of the nuchal translucency (NT) as part of a screening protocol for aneuploidy. Patients who returned for an anatomic survey between 16 and 20 weeks' gestation were evaluated. The sonographic markers and anomalies associated with the detection of trisomy 21 in the second trimester were analyzed. RESULTS: There were 42 fetuses (0.4%) with trisomy 21 identified in the study cohort of 9692 patients. Trisomy 21 was suspected at the NT scan in 28 fetuses (67%) and at the second-trimester anatomic survey in 14 (33%). In fetuses first suspected of having trisomy 21 in the second trimester, 9 of 14 had normal anatomic survey results, and 5 of 14 had congenital malformations. All 14 fetuses had soft markers for aneuploidy. A thickened nuchal fold was identified in 5 of 9 fetuses with trisomy 21 and normal anatomic survey results, all of whom had an NT of less than 3.0 mm at the initial screening scan. CONCLUSIONS: Second-trimester soft markers, especially a thickened nuchal fold, remain important observations in the detection of trisomy 21 by sonography among fetuses who have had first-trimester sonographic screening for aneuploidy.

Absent fetal nasal bone: what does it mean for the euploid fetus?

OBJECTIVES: Our purpose was to review the outcomes of singleton pregnancies in which an absent nasal bone was noted on first- or second-trimester sonography and aneuploidy was not present. METHODS: We identified singleton pregnancies from 2005 to 2011 in which an absent nasal bone was noted on sonography, aneuploidy was excluded, and newborn examinations were available for review. Sonographic reports were reviewed for anomalies, growth, and amniotic fluid volume. Newborn records were reviewed for physical examinations, complications, and radiologic or genetic tests. RESULTS: We identified 142 fetuses with a sonographic appearance of an absent nasal bone. We excluded 52 cases with aneuploidy and 33 in which newborn examination information was unavailable. Fifty-seven cases met inclusion criteria. For 3 euploid fetuses with an absent nasal bone on sonography, the presence of additional anomalies on second-trimester sonography ultimately signaled an adverse outcome: the presence of multiple congenital anomalies, a microdeletion syndrome, and a specific genetic diagnosis. CONCLUSIONS: All cases with adverse outcomes had additional prenatal sonographic findings. For the remainder, normal newborn examination findings provide some reassurance, especially in the setting of otherwise normal second-trimester sonographic findings. A microarray as a test for microdeletion and duplication syndromes in this situation could be considered.

Variations in management of mild prenatal hydronephrosis among maternal-fetal medicine obstetricians, and pediatric urologists and radiologists.

PURPOSE: There are no current guidelines for diagnosing and managing mild prenatal hydronephrosis. Variations in physician approach make it difficult to analyze outcomes and establish optimal management. We determined the variability of diagnostic approach and management regarding prenatal hydronephrosis among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists. MATERIALS AND METHODS: Online surveys were sent to mailing lists for national societies for each specialty. Participants were surveyed regarding criteria for diagnosing mild prenatal hydronephrosis and recommendations for postnatal management, including use of antibiotic prophylaxis, followup scheduling and type of followup imaging. RESULTS: A total of 308 maternal-fetal medicine obstetricians, 126 pediatric urologists and 112 pediatric radiologists responded. Pediatric urologists and radiologists were divided between Society for Fetal Urology criteria and use of anteroposterior pelvic diameter for diagnosis, while maternal-fetal medicine obstetricians preferred using the latter. For postnatal evaluation radiologists preferred using personal criteria, while urologists preferred using anteroposterior pelvic diameter or Society for Fetal Urology grading system. There was wide variation in the use of antibiotic prophylaxis among pediatric urologists. Regarding the use of voiding cystourethrography/radionuclide cystography in patients with prenatal hydronephrosis, neither urologists nor radiologists were consistent in their recommendations. Finally, there was no agreement on length of followup for mild prenatal hydronephrosis. CONCLUSIONS: We observed a lack of uniformity regarding grading criteria in diagnosing hydronephrosis prenatally and postnatally among maternal-fetal medicine obstetricians, pediatric urologists and pediatric radiologists. There was also a lack of agreement on the management of mild intermittent prenatal hydronephrosis, resulting in these cases being managed inconsistently. A unified set of guidelines for diagnosis, evaluation and management of mild intermittent prenatal hydronephrosis would allow more effective evaluation of outcomes.

Importance of renal abnormalities first identified in the third trimester after normal findings on a detailed second-trimester structural fetal survey.

OBJECTIVES: The purpose of this study was to evaluate the importance of renal abnormalities first identified in the third trimester of pregnancy after normal findings on a detailed second-trimester structural fetal survey. METHODS: Between March 1, 2007, and August 1, 2009, all patients having a sonographic examination in the third trimester who previously had normal findings on a second-trimester detailed structural fetal survey were retrospectively identified. Fetal renal abnormalities first detected in the third trimester and not seen during the second-trimester survey were tabulated. Neonatal follow-up was obtained for those with sonographic abnormalities. RESULTS: Overall, 4170 patients had third-trimester scans after normal findings on a detailed second-trimester survey. A new renal abnormality was detected in 77 (1.8%) of these third-trimester scans. Detailed postnatal imaging follow-up was available in 49 of 77 (63.6%), of which 44 (89.8%) had prenatal hydronephosis. Of these, 9 of 44 (20.5%) had reflux; 14 of 44 (31.8%) had normal findings or had hydronephosis that resolved on follow-up sonography after birth; and the rest had hydronephosis (13 of 44 [29.5%]), ureterovesical junction obstruction (3 of 44 [6.8%]), or ureteropelvic junction obstruction (5 of 44 [11.4%]). The other 5 fetuses with nonhydronephrotic renal abnormalities had pelvic kidneys (3) and unilateral renal agenesis (2). Two of those with reflux (22.2%) required surgery, and 1 of those with ureterovesical junction obstruction (33.3%) required surgery. CONCLUSIONS: Most renal abnormalities first identified in the third trimester after normal findings on a detailed second-trimester structural fetal survey were hydronephrosis, of which approximately one-third resolved after birth. Among the remaining neonates with persistent hydronephrosis, almost one-third had reflux that was not detected on the second-trimester anatomy scan.

The width of the uterine cavity is narrower in patients with an embedded intrauterine device (IUD) compared to a normally positioned IUD.

OBJECTIVE: The purpose of this study was to determine whether women with intrauterine devices (IUDs) embedded in the myometrium or cervix have a narrower fundal transverse endometrial diameter as seen on 3-dimensional (3D) sonography compared to women whose IUDs are in a normal location. METHODS: A sonographer blinded to the study hypothesis retrospectively evaluated the 3D images and reconstructed coronal views of the uterine cavity in 172 consecutive women who had an IUD in the uterus. The width of the endometrial cavity at the fundus of the uterus was measured transversely on the rendered coronal sonogram using the calipers on a picture archiving and communications system. The measurements obtained from women who had nonembedded IUDs were compared to those with embedded IUDs. RESULTS: Measurement of the width of the endometrial cavity at the fundus was successfully performed in 132 patients with nonembedded IUDs and 29 with embedded IUDs. The mean ± SD values of the fundal uterine cavity for the nonembedded and embedded IUDs were 32 ± 1.0 and 25 ± 0.8 mm, [corrected] respectively (P = .0003). CONCLUSIONS: Patients with embedded IUDs have a smaller fundal endometrial cavity diameter compared to those with normally placed IUDs as documented using 3D rendering of the uterus. Whether preprocedural 3D sonography for women who are IUD candidates would be useful deserves further study.

Structural anomalies in early embryonic death: a 3-dimensional pictorial essay.

OBJECTIVE: The purpose of this pictorial essay was to determine whether 3-dimensional (3D) surface rendering of a dead first-trimester embryo can provide any information for the loss. METHODS: Three-dimensional surface rendering was performed on a collection of dead first-trimester embryos with crown-rump lengths between 12 and 27 mm. These were compared with 2-dimensional (2D) images of the same embryos and with 2D images and 3D surface renderings of normally developing embryos. RESULTS: Surface rendering of dead embryos showed a variety of abnormalities in the contour and limb formation. CONCLUSIONS: The use of 3D sonography may provide insight into the etiology of first-trimester embryonic death.

ACR Appropriateness Criteria® Second and Third Trimester Vaginal Bleeding.

Vaginal bleeding can occur throughout pregnancy with varied etiologies. Although history and physical examination can identify many etiologies, imaging, in particular ultrasound (US), is the backbone of current medical practice. US pregnant uterus transabdominal, US pregnant uterus transvaginal, and US duplex Doppler velocimetry are usually appropriate for the evaluation of women with painless vaginal bleeding, those with painful vaginal bleeding, and also for those with second or third trimester vaginal bleeding with suspicion of or known placenta previa, low-lying placenta, or vasa previa. US cervix transperineal may be appropriate for those with painless or painful vaginal bleeding but is usually not appropriate for second or third trimester vaginal bleeding with suspicion of or known placenta previa, low-lying placenta, or vasa previa. Because the outcome of pregnancies is unequivocally related to the specific etiology of the vaginal bleeding, knowledge of imaging results directly informs patient management to optimize the outcome for mother and fetus. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Assessment of Gravid Cervix.

Preterm birth remains the leading cause of perinatal morbidity and mortality. Although the greatest risk factor for preterm birth is a history of prior preterm birth, a short cervical length (≤25 mm) before 24 weeks' gestational age is also associated with increased risk of spontaneous preterm delivery. As such, cervical length assessment has become of particular interest in predicting those patients at risk for preterm birth. Other clinical scenarios (eg, preterm labor, induction of labor, and active labor) may arise, in which assessment of the cervix may be of interest. Ultrasound is the mainstay imaging modality for assessing the gravid cervix, with transvaginal ultrasound recommended in patients at high risk for preterm birth or suspected preterm labor. Transperineal ultrasound is an alternate approach in those cases where transvaginal ultrasound in contraindicated. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Placenta Accreta Spectrum Disorder.

Placenta accreta spectrum disorder (PASD) is the current terminology recommended by the International Federation of Obstetrics and Gynecology (FIGO) and should replace terms such as abnormally adherent/invasive placenta or morbidly adherent placenta. PASD refers to a variety of potential clinical complications, which may result from abnormal placental implantation. More specifically, placenta accreta refers to a defect in the decidua basalis where the chorionic villi adhere directly to the myometrium with trophoblastic invasion. Accurate antenatal diagnosis is needed to plan for an appropriate delivery strategy at an experienced center in order to reduce maternal and potential fetal morbidity and mortality. Obtaining radiologic and clinical data when PASD is first suspected can play a significant role in formulating an appropriate delivery strategy. Depending on the clinical risk factors and initial imaging findings, transabdominal ultrasound of the pregnant uterus with duplex Doppler and transvaginal ultrasound as needed are the most appropriate imaging procedures. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Growth Disturbances-Risk of Fetal Growth Restriction.

Fetal growth restriction, or an estimated fetal weight of less than the 10th percentile, is associated with adverse perinatal outcome. Optimizing management for obtaining the most favorable outcome for mother and fetus is largely based on detailed ultrasound findings. Identifying and performing those ultrasound procedures that are most associated with adverse outcome is necessary for proper patient management. Transabdominal ultrasound is the mainstay of initial management and assessment of fetal growth. For those fetuses that are identified as small for gestational age, assessment of fetal well-being with biophysical profile and Doppler velocimetry provide vital information for differentiating those fetuses that may be compromised and may require delivery and those that are well compensated. Delivery of the pregnancy is primarily based upon the gestational age of the pregnancy and the ultrasound findings. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

ACR Appropriateness Criteria® Clinically Suspected Adnexal Mass, No Acute Symptoms.

There are approximately 9.1 pelvic surgeries performed for every histologically confirmed adnexal malignancy in the United States, compared to 2.3 surgeries per malignancy (in oncology centers) and 5.9 surgeries per malignancy (in other centers) in Europe. An important prognostic factor in the long-term survival in patients with ovarian malignancy is the initial management by a gynecological oncologist. With high accuracy of imaging for adnexal mass characterization and consequent appropriate triage to subspecialty referral, the better use of gynecologic oncology can improve treatment outcomes. Ultrasound, including transabdominal, transvaginal, and duplex ultrasound, combined with MRI with contrast can diagnose adnexal masses as benign with specific features (ie, functional masses, dermoid, endometrioma, fibroma, pedunculated fibroid, hydrosalpinx, peritoneal inclusion cyst, Tarlov cyst), malignant, or indeterminate. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Which patients benefit from a 3D reconstructed coronal view of the uterus added to standard routine 2D pelvic sonography?

OBJECTIVE: The objective of our study was to evaluate whether a 3D reconstructed coronal view of the uterus provides added benefit to standard gynecologic sonography. MATERIALS AND METHODS: Sixty-six consecutive patients underwent standard 2D pelvic sonography followed by 3D sonography. The physician determined whether the reconstructed coronal view of the uterus was helpful to make a diagnosis not possible with the 2D scan, helpful to be more confident of a diagnosis suspected on the basis of the 2D scan, or not helpful. Comparison of the demographic information, sonographic findings, and endometrial thickness was made between the patient groups. RESULTS: The 3D coronal views of the uterus added value to the 2D scan in 16 (24%) of the 66 patients. In five of these 16 patients, the coronal view added information about findings not seen using 2D imaging. In the other 11 patients, the diagnostic findings were more confidently seen using the coronal view. The coronal view added no information in 50 patients. The coronal view was helpful in four (12.5%) of 32 patients with an endometrium < 5 mm, one of six patients whose endometrium was incompletely seen with 2D sonography, and 11 (39%) of 28 patients whose endometrium measured > or = 5 mm. The coronal view did not provide benefit in patients who had normal findings on 2D scanning. In three patients referred because of infertility, uterine shape anomalies were diagnosed using the coronal view. CONCLUSION: The 3D coronal view of the uterus is a valuable adjunct to a 2D pelvic scan, particularly in patients presenting with infertility or suspected endometrial lesions. In addition, the coronal view is helpful in patients with an endometrium > or = 5 mm.

Assessment of the rate of uterine rupture at the first prenatal visit: a preliminary evaluation.

OBJECTIVE: To quantify the risk for symptomatic uterine rupture during a trial of labor after prior cesarean delivery based on factors that can be ascertained during early pregnancy. METHODS: From all trials of labor over a 12-year period, we determined those factors associated with an increased or decreased risk for uterine rupture and assigned scores. The following numerical scores were used: 2 points for > or = 2 prior cesarean scars, 1 point for interdelivery interval < or = 18 months, 1 point for maternal age of 30-39 years, 2 points for maternal age > or = 40 years, minus 1 point for women with prior vaginal delivery and one prior cesarean. RESULTS: There were 40 uterine ruptures in 4383 trials of labor (0.91%). Overall, the rate of uterine rupture varied by score: -1-0.26% (1/391), 0-0.25% (4/1613), 1-1.11% (21/1894), 2-2.43% (9/370), 3-3.70% (4/108), and 4-14.29% (1/7), p = .001. CONCLUSIONS: The rate of symptomatic uterine rupture during a trial of labor varies greatly depending on easily identified risk factors, and is low for women without risk factors.

ACR Appropriateness Criteria® First Trimester Vaginal Bleeding.

Vaginal bleeding is not uncommon in the first trimester of pregnancy. The majority of such patients will have a normal intrauterine pregnancy (IUP), a nonviable IUP, or an ectopic pregnancy. Ultrasound (US) is the primary imaging modality in evaluation of these patients. US, along with clinical observations and serum human chorionic gonadotropin levels, can usually distinguish these causes. Although it is important to diagnose ectopic pregnancies and nonviable IUPs, one should also guard against injury to normal pregnancies due to inappropriate treatment with methotrexate or surgical intervention. Less common causes of first trimester vaginal bleeding include gestational trophoblastic disease and arteriovenous malformations. Pulsed methods of Doppler US should generally be avoided in the first trimester when there is a normal, or a potentially normal, IUP. Once a normal IUP has been excluded, Doppler US may be useful when other diagnoses such as retained products of conception or arteriovenous malformations are suspected. MRI may occasionally be helpful as a problem-solving tool. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.