Dr Shipp is a Vice President with Diagnostic Ultrasound Associates, PC, Brookline, Massachusetts, and a Sonologist and Associate Professor of Obstetrics, Gynecology and Reproductive Biology at Brigham & Women’s Hospital, Department of OB/GYN, Boston.

Thomas D Shipp, MD, RDMS

Early pregnancy loss (miscarriage) is defined as a nonviable, intrauterine pregnancy with either an empty gestational sac or a gestational sac containing an embryo or fetus without cardiac activity within the first 12 6/7 weeks of gestation.

The cessation of development occurs in approximately 10-20% of clinically recognized pregnancies, increasing with advancing parental age.

 With the adoption of early home pregnancy testing, women are commonly referred for sonographic evaluations very early in gestation to determine pregnancy location and viability.

Although we believe ultrasound to be indispensable for the management of suspected early pregnancy failure, if performed too early or without strict adherence to guidelines, it may lead to inconclusive results or an incorrect diagnosis of an early pregnancy loss.

Ultrasonography (usually transvaginal) in combination with β-hCG and clinical history is instrumental for making the diagnosis of a nonviable pregnancy with certainty. 

Historically, these criteria were based on small studies; a CRL of ≥ 5mm and mean sac diameter of≥ 16-17 mm without an embryo were considered diagnostic for an early pregnancy loss.1,5Over the last decade, the reliability of these thresholds has been called into question.

In 2013, the Society of Radiologists in Ultrasound (SRU) convened a multispecialty panel on early first-trimester diagnosis of miscarriage and exclusion of a viable intrauterine pregnancy (cannot result in the birth of a live baby) and published a more conservative approach to defining a pregnancy as nonviable.

This change was made with the expectation of a diagnostic specificity of 100% (no false positives), while accounting for intra and interobserver variability in measurements as well as a range in practice conditions and experience.

 Inadvertent misclassification of potentially viable pregnancy as nonviable with resultant medical or surgical intervention resulting in the iatrogenic termination of a desired pregnancy has significant consequences to the family and may be an inciting factor in malpractice cases

This article will focus on the criteria for the sonographic diagnosis of a nonviable intrauterine pregnancy early in gestation, those sonographic findings that are suspicious to result in an early pregnancy loss, and the vital role of ultrasound in these frequent clinical scenarios. 

The sonographic findings are only one part of the puzzle in determining if a pregnancy is nonviable.

In order to apply the findings to a clinical situation, the obstetric care provider must take other clinical factors into consideration, such as accounting for the certitude of menstrual dating, the woman’s desire to continue the pregnancy until the definitive diagnosis is made along with logistical challenges such as the possibility of heavy bleeding leading to emergency room visits, unexpected passage of products of conception or unscheduled surgical procedures. 

On another note, when diagnosing a complete miscarriage, care must be taken that an intrauterine pregnancy has previously been confirmed. If not, serial β-hCG should be performed so as to not miss the diagnosis of an ectopic pregnancy.

Embryologic development in early pregnancy is quite linear and follows a dependable and fairly tight timetable (Figs. 1A, B, C, D). 

Ultrasound can reliably characterize the progression of a normally developing pregnancy from very early in gestation. 

The gestational sac is first identified at approximately 5 weeks, the yolk sac is visible at approximately 5.5 weeks and an embryo with cardiac activity located in close proximity to the yolk sac should be evident at approximately 6 weeks gestation. 

Embryonic cardiac activity is often seen when the embryo is first identified, measuring as little as 2 mm in length. The mean sac diameter is the average of three orthogonal diameters of the fluid portion of the gestational sac but is not as accurate as crown rump length for gestational dating.

Nomograms for development of embryonic length, heart rate, gestational sac diameter, and yolk sac diameter are available.

Transvaginal sonographic findings diagnostic of an early pregnancy loss

Given the newer, more conservative guidelines that are now well-accepted, a single transvaginal ultrasound identifying an embryo with a crown rump length of 7 mm or greater without cardiac activity or a gestational sac with a mean sac diameter of 25 mm or greater without an embryo is considered definitive proof that a pregnancy is nonviable

These metrics have also been validated in a prospective observational multicenter study to have a specificity of 100%.

Given the expected linear development of normal early pregnancies, the definitive diagnosis of an early pregnancy loss can also be made based on 

transvaginal ultrasound scans over a specified time interval (Figure 4). 

Figure 4- Time interval criteria for EPL.jpg

In a normally developing viable pregnancy, an embryo with cardiac activity must be demonstrated ≥11 days after a gestational sac with a yolk sac or ≥14 days in which a gestational sac without a yolk sac was identified by transvaginal sonography. 

The lack of cardiac activity after that interval of observation is definitive evidence for an early pregnancy loss. A shorter interval of observation with no embryonic heart motion would raise suspicion for an early pregnancy loss, however, it is not definitive.

Predictably, patients are anxious when the results of an indeterminant status of viability are disclosed, and the rationale behind the recommended time interval for follow up of the sonographic evaluation should be communicated.

Transvaginal sonographic findings suspicious (but not diagnostic) for early pregnancy loss

If an embryo is seen with a crown-rump length of <7 mm and without cardiac activity, it is suspicious for an early pregnancy loss (Figure 5). Similarly, a gestational sac with a mean sac diameter of 16-24 mm and no embryo is suspicious for an early pregnancy loss. 

The development of gestational sac landmarks is progressive and therefore the sonographic finding of an amnion with an adjacent yolk sac and without a visualized embryo is suspicious for an early pregnancy loss (Figure 6). It is important not to mistake a second yolk sac for the amnion as may be seen with early monochorionic diamniotic twins. If ascertainment of viability is indeterminant based on a suspicious finding, it is generally appropriate to repeat the ultrasound examination in 7-10 days.

Sonographic signs concerning for an increased risk of early pregnancy loss

In embryos in which cardiac activity is demonstrated, there are additional sonographic features that may signal an increased risk for early pregnancy loss. These include findings such as embryonic bradycardia, a small gestational sac, a large yolk sac, and a subchorionic hematoma.

In normal pregnancies, the embryonic heart rate progressively increases up to 8 weeks’ gestation. It has been 25 years since the seminal paper by Doubilet and Benson in which the rate of first-trimester pregnancy loss was directly correlated with embryonic heart rate 14 (Figure 7). 

These investigators evaluated 1,185 early pregnancies and provided pregnancy loss rates stratified by the degree of bradycardia and gestational age. The slower the heart rate, the higher the risk of pregnancy loss (Table 1).

A recent systematic review and diagnostic accuracy meta-analysis evaluating the prediction of miscarriage found that the most predictive factor for early pregnancy loss was embryonic/fetal heart rate.

 This predictive effect was even more pronounced among those with bleeding in early pregnancy. 

In their hierarchical summary receiver operating characteristic model curve, the authors found that bradycardia had a sensitivity of 68.4%, specificity of 97.8%, positive likelihood ratio of 31.7, and negative likelihood ratio of 0.32 for predicting early pregnancy loss. 

For those with bleeding the sensitivity of heart rate to predict miscarriage increased further (sensitivity, 84.2%, specificity, 95.7%, positive likelihood ratio, 19.51, and negative likelihood ratio, 0.16). 

The authors found that the best cut-off for heart rate was <110 bpm for the prediction of miscarriage. A heart rate of >134 bpm at seven weeks’ gestation and a heart rate of >158 bpm at 8 weeks’ gestation were predictive of on-going pregnancies. 

These data highlight the importance of assessing embryonic heart rate by M-mode while performing an early ultrasound, as it is the most predictive sign of pregnancy loss. It must be recognized, however, that in an embryo of less than 6 weeks gestation, the very initiation of cardiac pulsations may be reflected in a slower rate,

 which underscores the value of a repeat scan. 

A bradycardic heart rate should prompt a follow-up sonographic examination to assess embryonic viability, whereas a normal heart rate provides considerable reassurance for the patient.

Small gestational sac in relation to crown-rump length

On occasion, an embryo with a normal heart rate will appear sonographically ‘crowded’ within the gestational sac (Figure 8), a finding which has been associated with an increased risk of early pregnancy loss.

Objectively, this has been characterized as a mean sac size – crown rump length (MSS-CRL) of < 5 mm.

 Bromley et al. demonstrated that the risk of miscarriage was 94% with a small gestational sac in the first trimester despite a normal cardiac rate. 

In a larger and more recent study of patients conceiving via IVF, the early pregnancy loss rate among patients with a MSS-CRL of< 5 mmwas approximately 44% compared with a referent population with a MSS-CRL of 5-9.9mm in whom the loss rate was 15.8 % (

Of note, there is no appreciable increase in the risk of early pregnancy loss between those conceiving using assisted reproductive technology compared with spontaneously conceived pregnancies.

 The sonographic finding of an embryo in a small gestational sac should prompt follow-up sonography to assess persistence of development.

The yolk sac is the first structure that is identifiable within the gestational sac by transvaginal ultrasound when the gestational sac reaches 8-10 mm. Abnormalities in size and appearance of the yolk sac have been reported to be associated with an increased risk of pregnancy loss, although not all studies have found this to be a useful metric for predicting pregnancy loss.

The sonographic assessment of the yolk sac in asymptomatic patients as a predictor of miscarriage has shown sensitivities ranging from 17 to 69% and specificities ranging from 79 to 99%.16A yolk sac of greater than 7 mm has been suggested as a concerning threshold for an increased risk of pregnancy loss, although methods of measurement have been inconsistent.

Recent data suggests yolk sac diameter does not improve the prediction of miscarriage over bradycardic heart rates and limited embryonic/fetal crown-rump length.

One should be very cautious in the use of this sonographic sign, especially as an isolated finding, for prediction of first-trimester pregnancy loss until stronger guidance from the literature is available.

In a well dated pregnancy, a small crown-rump length for gestational age may reflect early growth disturbance and is associated with an increased risk of aneuploidy as well as early pregnancy loss.

 Among an IVF population with clear gestational age determination, those with a crown-rump length of < 10% had an increased risk of miscarriage as compared to those normally grown, 17.2% vs. 6.6%,

Should a much smaller than expected crown-rump length be encountered in the first trimester, especially those that would lead to a change in pregnancy dating, a follow-up evaluation to assess interval growth in 2 weeks should be considered.

Bleeding in early pregnancy is common, and a subchorionic hematoma can be sonographically identified in this setting (Figure 9). Subchorionic hematoma has been associated with an increased rate of pregnancy loss, especially if the hematoma is large, associated with bleeding or the patient is 35 years of age or older.

The method of assessing the size of the subchorionic hematoma has been controversial, but it appears that in one study, the subjective assessment of hematoma size based on the fraction of the gestational sac size correlates best with first-trimester pregnancy outcome.

 The rate of spontaneous pregnancy loss in the first trimester is reported to be highest for those hematomas diagnosed before 8 weeks (19.6%) compared to those diagnosed after 8 weeks (3.6%; 

A review and meta-analysis demonstrated that the identification of a subchorionic hematoma was associated with an increased risk for miscarriage, increasing from 8.9% to 17.6%, pooled OR 2.18, 95% CI 1.29, 3.68).

A recent retrospective cohort study of 2446 patients with singletons presenting for ultrasound between 6 weeks and 13+6d weeks at a single center, demonstrated that subchorionic hematoma was associated with an increased risk of pregnancy loss before 20 weeks gestation (7.5% vs. 4.9% 

=.026) on univariate analysis, however, when adjusting for patient age and bleeding, this association was no longer significant.

Similarly, these authors showed no increased risk of adverse outcome later in gestation.

 Given the possible increased risk for pregnancy loss, follow-up sonography can be considered in these cases.

A chorionic bump is a focal convex protuberance that develops at the choriodecidual surface and protrudes into the gestational sac in the early first trimester, likely reflecting a hematoma or necrotic decidua (Figure 10). 

The finding has been associated with an increased risk of early pregnancy loss when identified before 11 weeks gestation. If a chorionic bump is identified and the pregnancy is otherwise normal in appearance with a normal heart rate, the live birth rate has been reported to be approximately 83%.

In addition, there was no significant relationship between the volume of the chorionic bump or bleeding per vagina and the risk of pregnancy loss.

 In the latter part of the first trimester, the presence of a chorionic bump is not thought to be clinically relevant.

Ultrasound is a powerful tool in the diagnosis and prediction of early pregnancy loss. 

Practitioners must be diligent to follow guidelines for diagnosing a pregnancy as non-viable in order to prevent an iatrogenic pregnancy termination. Although some patients will have sonographic findings that definitively allow the diagnosis of a failed pregnancy, many will have findings that are suggestive or inconclusive of miscarriage. A follow-up scan can be very helpful in these cases.

The timing of the sonographic evaluation is important in management, as too early an evaluation is likely to lead to an ultrasound report of a pregnancy of unknown location or an intrauterine pregnancy of uncertain viability. 

In a study of asymptomatic women attending an early pregnancy ultrasound unit, the diagnosis of a miscarriage could not be made on initial ultrasound examination until 35 days from LMP and most miscarriages were diagnosed when the first assessment was between 63 and 85 days after the LMP.

These authors recommended that in order to reduce the number of inconclusive scans, asymptomatic women without a history of ectopic, delay an initial ultrasound until 49 days from LMP.

Healthcare providers taking care of women suspected of having or experiencing an early pregnancy loss should have training in how to compassionately and effectively communicate difficult news as the patient is at risk for posttraumatic stress, anxiety and depression.

practices in the Department of OB/GYN at Massachusetts General Hospital in Boston and with Diagnostic Ultrasound Associates, PC, in Brookline, Mass. She is a part-time professor at Harvard Medical School.

practices in the Department of OB/GYN at Brigham & Women’s Hospital in Boston and with Diagnostic Ultrasound Associates, PC, in Brookline, Mass. He is an associate professor at Harvard Medical School.

1.ACOG Practice Bulletin No. 200: Early Pregnancy Loss. 

2.Wise LA, Wang TR, Willis SK, Wesselink AK, Rothman KJ, Hatch EE. Effect of a Home Pregnancy Test Intervention on Cohort Retention and Pregnancy Detection: A Randomized Trial. 

3.Ammon Avalos L, Galindo C, Li DK. A systematic review to calculate background miscarriage rates using life table analysis. 

4.Bottomley C, Van Belle V, Mukri F, et al. The optimal timing of an ultrasound scan to assess the location and viability of an early pregnancy. 

5.Doubilet PM, Benson CB, Bourne T, et al. Diagnostic criteria for nonviable pregnancy early in the first trimester. 

6.Pexsters A, Luts J, Van Schoubroeck D, et al. Clinical implications of intra- and interobserver reproducibility of transvaginal sonographic measurement of gestational sac and crown-rump length at 6-9 weeks' gestation. 

7.Abdallah Y, Daemen A, Kirk E, et al. Limitations of current definitions of miscarriage using mean gestational sac diameter and crown-rump length measurements: a multicenter observational study. 

8.Shwayder JM. Waiting for the tide to change: reducing risk in the turbulent sea of liability. 

9.Farren J, Jalmbrant M, Falconieri N, et al. Posttraumatic stress, anxiety and depression following miscarriage and ectopic pregnancy: a multicenter, prospective, cohort study. 

10.Committee on Obstetric Practice tAIoUiM, the Society for Maternal-Fetal M. Committee Opinion No 700: Methods for Estimating the Due Date. 

Articles

Ultrasound technology can be an indispensable tool for the management of suspected early pregnancy loss. 

An imaging approach to early pregnancy failure

Dr Bromley is a Vice President at Diagnostic Ultrasound Associates, PC, Brookline, Massachusetts, and a Sonologist and Professor of Obstetrics, Gynecology and Reproductive Biology (part time) at Massachusetts General Hospital, Department of OB/GYN, Boston.

Neither author has a conflict of interest to report in respect to the content of this article.

Use of long-acting reversible contraceptives (LARCs) among premenopausal women has increased 5-fold during the past decade.

 The intrauterine device (IUD) is the most popular LARC, used by 6.4% of women aged 15–44 to prevent pregnancy.

 IUDs have also been proposed as a treatment for menorrhagia.

Figure 1A Transvaginal sagittal view of the uterus demonstrating the highly echogenic shaft of the ParaGard IUD.The 2 most commonly available types of IUDs in the United States are nonhormonal copper-containing devices (copper T-380A; ParaGard, Duramed Pharmaceuticals), and hormone-releasing systems Mirena and Skyla (Bayer HealthCare Pharmaceuticals Inc.). Both have a T-shaped polyethylene frame compounded with barium sulfate to make them radiopaque, enhancing their appearance by radiography but not by ultrasound.

Figure 1B Transvaginal transverse view of the uterus demonstrating the highly echogenic arms of the ParaGard IUD.The ParaGard has a thin copper wire wrapped around the shaft and along a section of each of the straight arms, making it brightly echogenic by ultrasound (Figure 1 A,B,C). The Mirena and Skyla have slightly bowed arms and a central silicone reservoir around the stem that releases levonorgestrel (Figure 2,3).

The ParaGard and Mirena measure 32 mm across the arms and have a shaft length of 36 mm and 32 mm, respectively. The Skyla is slightly smaller with a transverse arm dimension of 28 mm and a length of 30 mm. In addition the Skyla has a sonographically visible small silver ring on the stem at the base of the arms. Monofilament retrieval strings are attached to the most inferior portion of the stem and can occasionally be sonographically recognized, depending on their location and other imaging characteristics such as the presence of cervical mucous (Figure 4).

Figure 1C 3D coronal view of the uterus demonstrating the expected placement of the ParaGard IUD.IUDs are well tolerated by most women, with continuation rates of approximately 80%.

 Changes in menstrual bleeding may occur after placement of an IUD. Heavy bleeding and dysmenorrhea are more common with copper IUDs; amenorrhea is more common with progesterone-containing IUDs.

 Abnormal bleeding, pelvic pain, and inability to identify retrieval strings on physical exam may trigger a referral for imaging of the pelvis.

Figure 2 3D coronal view of the uterus showing normal placement of the Mirena IUD. The arms of the IUD are slightly embedded in the myometrium. String is demonstrated by an arrow.

Sonography should be the first choice for imaging the female pelvis.

 It is readily available, much less expensive than other imaging methods, and does not place the patient at risk for radiation exposure. Multiple studies have demonstrated the utility of sonography in visualizing IUDs and characterizing their placement.

 Although most IUDs can be visualized with transabdominal ultrasonography, higher-frequency transvaginal ultrasound probes with resultant heightened resolution make transvaginal sonography optimal for evaluation of IUDs.

Figure 3 3D coronal view of the uterus showing normal placement of the Skyla IUD. The transverse diameter of the widest part of the endometrium is 30 mm.

Figure 4 3D coronal view of the uterus showing normal placement of the IUD. The brightly echogenic string is visualized looping up and crossing over the shaft of the IUD and then extending toward the lower uterus (arrow).Sonographic evaluation of the positioning of an IUD is greatly enhanced by identification of the coronal view of the uterus, a plane that is not often obtainable using 2D imaging. Three-dimensional sonography allows visualization of the coronal view of the uterus with minimal post-processing manipulation of the uterine volume and is critical for determining malposition of an IUD.

If an IUD cannot be visualized by 3D pelvic sonography, a secondary imaging procedure such as abdominal/pelvic x-rays or computed tomography may be necessary.

Abuhamad et al. have demonstrated the ease of attaining the coronal view of the uterus in a standardized fashion.12 To perform this so-called Z technique, follow these key steps:

• Obtain a midsagittal view of the uterus and magnify the image so that it includes the corpus and lower uterine segment. Obtain a 3D image and display it in a multiplanar view so that 3 orthogonal planes are on a single frame. Configure the display so that the A frame is the acquisition plane (sagittal view), the B frame is the transverse view and the C frame is the coronal view. A “reference dot” located at the same anatomic point in each plane is the rotational point around which the image is rotated (Figure 5A).

• Place the reference dot in the midpoint of the endometrial stripe in the sagittal plane of the uterus, which should be in the “A” frame.

• Using the Z rotation, manipulate the sagittal view of the endometrial echo so that it is horizontal (Figure 5A).

• Place the reference or marker “dot” in the midpoint of the endometrial stripe in the transverse plane of the uterus, frame B (Figure 5B).

• Using the Z rotation, manipulate the endometrial stripe so that the short axis of the transverse plane is horizontal.

• You should now see the mid-coronal plane of the uterus on the C frame (Figure 5B).

• Use the Z rotation to manipulate the image so that it is demonstrated in the conventional orientation.

• You can then display the image as a single plane for optimal evaluation.

The coronal plane can also be demonstrated with a rendering technique using the same principles. In that case, adjustment of the position of the endometrial echo in boxes A and B is identical; however, the render mode is used and the line of interest is placed over the endometrium (Figure 6).

Given biologic variability, minor manipulation may be necessary to rotate all planes to obtain a coronal view of the uterus and check the position of the IUD. The same standard orientation is recommended for both anteverted and retroverted uteruses. Therefore the initial manipulation of the volume of a retroverted uterus should be approximately 180° so that the anterior wall of the uterus is at the top of the image, making it appear to be anteverted (Figure 7 A and B).

With this simple technique the coronal plane of the uterus can be obtained in almost all women after acquiring the volume during transvaginal sonography. If the IUD is in the expected location within the uterus, it should be easy to identify in the coronal plane. If the IUD is not in its expected location, further manipulation may be necessary to characterize its position and to ascertain its location. On occasion, an IUD is not in its expected location, and the “T-shaped” view of the device is not in the same plane as the coronal view of the endometrium and, therefore, they cannot be displayed in one image. In some cases, visualization of the acoustic shadow of the IUD may help in determining its location

Moschos and Twickler demonstrated that the copper T is more easily identified sonographically than the levonorgestrel-containing IUDs. These authors also showed that 3D sonography enhanced the “conspicuity” of both types of IUDs over conventional 2D ultrasound evaluation.

 Chen et al. evaluated malpositioned IUDs using the gold standard of hysteroscopy, laparoscopy, or laparotomy and found that 2D imaging correctly identified 65% of malpositioned IUDs whereas 3D ultrasound correctly identified 84% of malpositioned IUDs.

Nowitzki et al. provided definitions for different types of abnormal or malpositioned IUDs.

 passage of the IUD either partially or completely through the external cervical os. The IUD is not seen on pelvic sonography.

 rotation or inferior positioning of the IUD in the lower uterine segment or cervix (Figure 8).

 penetration of the IUD into the myometrium without extension through the serosa.

 partial or complete penetration of the IUD through the serosa (Figure 9).

 retention of a broken piece of the IUD after expulsion or removal. Fragmentation of a retained IUD has been occasionally seen in vivo as well.

Displacement of an IUD from its expected location at the fundus of the uterus will almost always lead to some part of the IUD being embedded within the myometrium. Complete perforation may be difficult to identify by ultrasound because the surrounding bowel can hamper or prevent visualization. In these cases, other imaging modalities may be necessary.

When a patient has an IUD and is referred for abnormal bleeding and pain, it is important to determine if the IUD position could be associated with the symptoms. Benacerraf et al. demonstrated that 75% of patients with an IUD referred with either pain or bleeding had a malpositioned IUD as compared to 35% of those without those symptoms.

 Braaten et al. demonstrated that malpositioned devices were present on 10.4% of scans among women having pelvic sonography for any indication and were usually in the lower uterine segment. In that study, approximately two-thirds of malpositioned IUDs were removed, resulting in a higher rate of pregnancy (due to non-initiation of another effective contraceptive method) as compared to those with normally positioned IUDs.

 In addition, malpositioned copper devices have decreased contraceptive efficacy if not located in the uterine fundus.

Shipp et al. demonstrated that the endometrial cavity was narrower in patients with embedded or malpositioned IUDs as compared to those with normally positioned IUDs.

 Liang et al. demonstrated that women with larger transverse diameters of the coronal view of the uterus have a higher risk of IUD expulsion.

 Patients who are clinically suspected of having a small or large uterus may benefit from a pre-IUD insertion ultrasound to assess the maximal width of the endometrial cavity. This information may help determine the size of IUD that should be inserted or even whether an IUD is a reasonable option (Figure 10). Ultrasound may also be helpful for evaluation of IUD placement in women with uterine anomalies.

Further research is needed before an evidence-based recommendations can be made about IUD use in women with uterine anomalies.

IUDs have increasingly been inserted immediately postpartum, including following cesarean delivery. The advantage is a higher proportion of continued IUD use at 6 months postpartum when compared to interval IUD placement; however, approximately one-quarter are expelled or removed for malposition by 6 weeks postpartum.

IUDs can typically be inserted and removed in straightforward office procedures. At times, however, ultrasound can be uniquely advantageous in assisting both insertion and removal of the devices. If a patient’s uterus is severely anteverted or retroverted, direct sonographic visualization can offer some reassurance to a clinician that the IUD is being appropriately placed within the uterus (Video). Similar difficulties may be encountered when an IUD is removed. At times the string may not be visible if it has retracted into the uterus or the IUD is partially embedded. In those cases, removal under direct ultrasound guidance may offer great benefit, avoiding the need to do the procedure in the operating room

1. Branum AM, Jones J. Trends in long-acting reversible contraception use among U.S. women aged 15-44. National Center for Health Statistics Data Brief, Number 188, February 2015.

2. Lethaby A, Munawar H, Rishworth JR, Rees MC. Progesterone or progestogen-releasing intrauterine systems for heavy menstrual bleeding. (Review) The Cochrane Collaboration. 2015.

3. Long-acting reversible contraception: implants and intrauterine devices. American College of Obstetricians and Gynecologists. Practice Bulletin Number 121, July 2011, Reaffirmed 2013.

4. Benacerraf BR, Shipp TD, Bromley B. Three-dimensional ultrasound detection of abnormally located intrauterine contraceptive devices which are a source of pelvic pain and abnormal bleeding. Ultrasound Obstet Gynecol. 2009;34:110–115.

5. Benacerraf BR, Abuhamad AZ, Bromley B. et al. Consider ultrasound first for imaging the female pelvis. Am J Obstet Gynecol. 2015;212:450–455.

6. Sakhel K, Benson CB, Platt LD, et al. Begin with the basics. Role of 3-dimensional sonography as a first-line imaging technique in the cost-effective evaluation of gynecologic pelvic disease. J Ultrasound Med. 2013;32:381–388.

7. Shipp TD, Bromley B, Benacerraf BR. The width of the uterine cavity is narrower in patients with an embedded intrauterine device (IUD) compared to a normally positioned IUD. J Ultrasound Med. 2010;29:1453–1456.

8. Moschos E, Twickler DM. Does the type of intrauterine device affect conspicuity on 2D and 3D ultrasound? AJR. 2011;196:1439–1443.

9. Chen XY, Guo QY, Wang W, Huang LL. Three-dimensional ultrasonography versus two-dimensional ultrasonography for the diagnosis of intrauterine device malposition. Int J Gyn Obstet. 2015;128:157–159.

10. Nowitzki KM, Hoimes ML, Chen B, Zheng LZ, Kim YH. Ultrasonography of intrauterine devices. Ultrasonography 2015;34:183-194.

11. Agacayak E, Tunc SY, Icen MS, Oguz A, Ozler A, Turgut A, Basaranoglu S. Evaluation of predisposing factors, diagnostic and treatment methods in patients with translocation of intrauterine devices. Obstet Gynaecol Res. 2015;41:735–741.

12. Abuhamad AZ, Singleton S, Zhao Y, Bocca S. The Z Technique: An easy approach to the display of the midcoronal plane of the uterus in volume sonography. J Ultrasound Med. 2016;25:607–612.

13. Valsky DV, Cohen SM, Hochner-Celnikier D. et al. The Shadow of the Intrauterine Device. J Ultrasound Med. 2006;25:613–616.

14. Asch E, Levine D, Brook OR. Fractured intrauterine device copper sheath with an intact Polyethylene Core. J Ultrasound Med. 2013;32:1877–1878.

15. Braaten KP, Benson CB, Maurer R, Goldberg AB. Malpositioned intrauterine contraceptive devices; risk factors, outcomes, and future pregnancies. Obstet Gynecol. 2011;118:1014–1020.

16. Anteby E, Revel A, Ben-Chetrit A et al. Intrauterine device failure: relation to its location within the uterine cavity. Obstet Gynecol. 1993;81:112–114.

17. Liang H, Li L, Yuan W, Zou Y, Gao E-S, Duffy JMN, Wu S-C. Dimensions of the endometrial cavity and intrauterine device expulsion or removal for displacement: a nested case-control study. BJOG. 2014;121:997–1004.

18. Levi EE, Stuart GS, Zerden ML, Garrett JM, Bryant AG. Intrauterine device placement during Cesarean delivery and continued use 6 months postpartum. Obstet Gynecol. 2015;126:5–11.

19. Dias T, Abeykoon S, Kumarasiri S, Gunawardena C, Padeniya T, D’Antonio F. Use of ultrasound in predicting success of intrauterine contraceptive device insertion immediately after delivery. Ultrasound Obstet Gynecol. 2015;46:104–108.

20. Verma U, Astudillo-DÃ¡valos FE, Gerkowicz SA. Safe and cost-effective ultrasound guided removal of retained intrauterine device: our experience. Contraception. 2015;92:77–80.

Pelvic sonography, especially transvaginal 3D imaging, is critical for identifying malpositioned and embedded IUDs.

Thomas D Shipp, MD, RDMS

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