Obstetric Ultrasound Examination (Position Paper)
Overview and Justification
Obstetric care is an integral part of many family physicians’ scope of practice and an important component of family medicine residency training.1,2 Maternity care in rural and underserved communities is disproportionately provided by family physicians, so their ability to perform obstetric ultrasound examination improves patients' access to care.3,4 Patients also benefit from more rapid diagnosis and treatment, and enhanced continuity of care. An American Academy of Family Physicians (AAFP)/American College of Obstetricians and Gynecologists (ACOG) joint statement asserts that access to high-quality maternity care is an important public health concern in the United States.1 The primary objective must be the highest standard of obstetric care, regardless of specialty.
In addition to improved access and continuity of care, potential benefits of obstetric ultrasound examination performed by a family physician include the following:
- Availability of clinical information at the time of patient contact in rural or underserved areas
- Immediate assessment of urgent clinical problems
- Sensitivity and specificity of ultrasound examination performed by a physician who knows the patient
- Reductions in time and cost
- The likelihood that primary care allows more time than referral care for educational interaction with
Family physicians who perform obstetric ultrasound examination must guard against potential drawbacks, including the following:
- Potential for misuse of the technology, particularly nonmedical uses5,6
- Risk that easy availability will lead to overutilization
- Patients’ unrealistic expectations related to outcomes or the power of the technology
- Possibility that increasing technological complexity will require additional training
- Possibility that increasing volume will lead physicians to delegate examinations to ultrasound
technicians, thus distancing physicians from their patients
- Possibility that other clinical duties may not allow time for ultrasound examinations in the physician's
- Ongoing interspecialty conflicts regarding the utilization of this technology
Section I – Scope of Practice for Family Physicians
Family medicine is a specialty based on comprehensive care that encompasses a wide range of medical services. Family physicians practice among diverse populations and in geographically varied settings, including rural communities. They choose a personal scope of practice based on factors that include their training experiences, their practice interests, and the needs of their patient populations.
Broadly speaking, the following indicate that obstetric ultrasound examination is within the current scope of family medicine:
- According to the AAFP Member Census (as of December 31, 2017), 8 percent of AAFP members
offer obstetric ultrasound imaging in their practice.7
- The AAFP’s recommended curriculum guidelines for maternity care state that family medicine
residents should demonstrate the ability to independently perform limited obstetric ultrasound
examination (i.e., fetal position, amniotic fluid index, placental location, and cardiac activity) as a
core skill.2 The guidelines also recommend additional experience for family medicine residents who
are planning to practice in communities without readily available obstetric-gynecologic consultation
and who will need to provide a more complete level of obstetric-gynecologic services. These
advanced skills include clinical assessment of gestational age; ascertainment of accurate dating with
ultrasound, if indicated; and ultrasound-guided amniocentesis during the second trimester and third
- The Society of Teachers of Family Medicine (STFM) Group on Hospital Medicine and Procedural
Training includes basic prenatal ultrasound (i.e., amniotic fluid index, fetal presentation, and
placental location) on its list of core procedures for family medicine that all residents must be able to
perform independently by graduation.8 Advanced prenatal ultrasound (i.e., dating and anatomic
survey) is listed as a procedure that family medicine residents must have exposure to and be given
the opportunity to be trained to perform independently by graduation.A task force of Council of
Academic Family Medicine (CAFM) member organizations and experienced faculty and program
directors published a consensus statement for procedural training in family medicine residency that
includes basic obstetric ultrasound (i.e., amniotic fluid index, fetal presentation, and placental
location) as a procedure that all graduates of U.S. family medicine programs should be adequately
trained to perform.9
- In the United States, there are approximately 40 family medicine fellowships in obstetrics.10
Physicians in these programs are trained to perform obstetric ultrasound examination,11 and many
subsequently practice in rural and/or underserved areas.
Obstetric ultrasound examination appropriately enhances the diagnostic and therapeutic capabilities of family physicians. Applications in family medicine can be divided into the following general areas:
- First trimester diagnostic pregnancy care
- Second or third trimester diagnostic pregnancy care
- Ultrasound-guided procedures (e.g., amniocentesis)
- Emergency care of acutely ill patients in labor and delivery, in the emergency department, and in
Every family physician who delivers infants can make use of ultrasound examinations for a limited number of applications that often arise suddenly and can have significant impact on patient care.12 These applications—which include assessment of fetal life, fetal number, fetal presentation, quantity of amniotic fluid, and placental location—are readily learned by family physicians and are included as an option in the AAFP-sponsored Advanced Life Support in Obstetrics (ALSO®) courses. Modern obstetric care benefits from the availability of ultrasound equipment in, or readily accessible to, the labor and delivery area for these purposes.
Section II – Clinical Indications
The American Institute of Ultrasound in Medicine’s (AIUM’s) practice parameter for the performance of obstetric ultrasound examination lists indications for first-trimester ultrasound examination (Table 1) and second-/third-semester ultrasound examination (Table 2).
Table 1. Indications for First-Trimester Ultrasound Examination
First-trimester ultrasound examination is indicated for the following:
- Confirm presence of intrauterine pregnancy
a. Suspected etopic pregnancy
b. Pelvic pain
c. Maternal pelvic masses and/or uterine abnormalities
d. Suspected hydatidiform mole
- Identify cause of vaginal bleeding
- Estimate gestational age
- Diagnose or evaluate multiple gestations
- Confirm cardiac activity
- Use as adjunct to procedures such as chorionic villus sampling, embryo transfer, and localization and
removal of an intrauterine device
- Assess for certain fetal anomalies (e.g., anencephaly) in high-risk patients
- Measure nuchal translucency when screening for fetal aneuploidy
Information from American Institute of Ultrasound in Medicine. AIUM practice guideline for the performance of obstetric ultrasound examinations. J Ultrasound Med. 2013;32(6):1083-1101.
Table 2. Indications for Second- and Third-Trimester Ultrasound Examination
Second- and third-trimester ultrasound examination is indicated for the following:
- Screen for fetal anomalies
a. Fetal anatomy
b. Fetal growth
c. Vaginal bleeding
d. Abdominal or pelvic pain
e. Cervical insufficiency
f. Suspected multiple gestation
g. Significant discrepancy between uterine size and clinical dates
h. Pelvic mass
i. Suspected hydatidiform mole
j. Suspected ectopic pregnancy
k. Suspected fetal death
l. Suspected uterine abnormalities
m. Fetal well-being
n. Suspected amniotic fluid abnormalities
o. Suspected placental abruption
p. Premature rupture of membranes and/or premature labor
q. Abnormal biochemical markers
r. Fetal condition in late registrants for prenatal care
- Estimate gestational age
- Determine fetal presentation
- Use as adjunct to:
a. Amniocentesis or other procedure
b. Cervical cerclage placement
c. External cephalic version
- Conduct follow-up evaluation of:
a. Fetal anomaly
b. Placental location for suspected placenta previa
- History of previous congenital anomaly
- Assess for findings that may increase the risk for aneuploidy
Information from American Institute of Ultrasound in Medicine. AIUM practice guideline for the performance of obstetric ultrasound examinations. J Ultrasound Med. 2013;32(6):1083-1101.
Under the Choosing Wisely campaign—a national effort to reduce waste in the health care system and avoid unnecessary or harmful tests and treatment—ACOG recommends that physicians should not perform prenatal ultrasounds for non-medical purposes (e.g., solely to create keepsake videos or photographs).5 ACOG’s recommendation states: “While obstetric ultrasound has an excellent safety record, the U.S. Food and Drug Administration [FDA] considers keepsake imaging as an unapproved use of a medical device. The American Institute of Ultrasound in Medicine also discourages the non-medical use of ultrasound for entertainment purposes. Keepsake ultrasounds are not medical tests and should not replace a clinically performed sonogram.”5
In a standard first-trimester obstetric ultrasound examination, the uterus, cervix, adnexa, and cul de sac region should be examined.13,14 The presence, size, location, and number of gestational sac(s) should be evaluated, and gestational sac(s) should be examined for the presence of a yolk sac and embryo/fetus. When an embryo/fetus is present, crown-rump length and cardiac activity should be documented.
For ultrasound examinations performed in the second trimester and the third trimester, the American College of Radiology (ACR), the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the Society for Maternal-Fetal Medicine (SMFM), the Society of Radiologists in Ultrasound (SRU), ACOG, and AIUM have adopted the following uniform terminology: standard, limited, and specialized (Table 3).13,15,16
Table 3. Classification of Second- and Third-Trimester Ultrasound Examination
A. Standard Examination13,14
A standard obstetric ultrasound examination includes:
- Evaluation of fetal presentation and number
- Evaluation of amniotic fluid volume
- Evaluation of cardiac activity
- Evaluation of placental position
- Evaluation of fetal biometry
- Anatomic survey
- Examination of maternal cervix and adnexa, as clinically appropriate and when technically
B. Limited Examination13,14
A limited examination is performed to answer a specific clinical question (e.g., to verify fetal presentation in a patient who is in labor or to confirm fetal heart activity in a patient experiencing vaginal bleeding), but it does not replace a standard examination.
C. Specialized Examinations13,14,17
Specialized examinations are typically performed starting at 32 weeks of gestation but may be done earlier if there are multiple risk factors or particularly worrisome problems. A specialized anatomic ultrasound examination is performed when an anomaly (e.g., fetal growth restriction) is suspected based on the history, laboratory abnormalities, or the results of a limited or standard examination. A biophysical profile (BPP) is a specialized examination that combines ultrasound examination and fetal heart rate monitoring to evaluate the amount of amniotic fluid, and fetal heart rate, breathing, body/limb movements, and muscle tone. A BPP is typically recommended when there is an increased risk of problems that could result in pregnancy complications or lead to stillbirth. Other specialized examinations include fetal Doppler ultrasound, fetal echocardiogram, or additional biometric measurements.
Section III – Training Methodology
Family physicians can acquire skills for performing obstetric ultrasound examination during their family medicine residency training or a post-residency fellowship. Obstetric ultrasound examination courses organized and presented by family physicians and sponsored by the AAFP have been offered since 1989. Other organizations also offer training through accredited continuing medical education (CME) activities and workshops. Most physicians who have a base of knowledge in maternal-fetal anatomy and physiology can rapidly learn basic (limited) applications of obstetric ultrasound examination, including assessment of fetal life, fetal number, fetal presentation, quantity of amniotic fluid, and placental location.12 However, learning advanced applications require significant additional study and supervised practice.
Key elements of standard ultrasound examinations in the first trimester and second and third trimesters have been defined, with very little disagreement, by the AIUM, ACOG, and ACR.13,14 Existing training methodologies address these elements. In the ideal situation, a physician would engage in a preliminary period of extensive reading, followed by a basic course that includes didactic and experiential activities. This would be followed by practice that is supervised either directly or through an audit of recorded scans. The efficacy of these methodologies has been established by direct examination of scanning capabilities, written tests, objective measurements of acquired basic data, comparison of patient outcomes, and comparison of family physicians' results to those of other providers.
Section IV – Testing, Demonstrated Proficiency, and Documentation
The ACOG practice guideline on ultrasound in pregnancy states the following qualifications for competence in obstetric ultrasound examination: “Physicians who perform, evaluate, and interpret diagnostic obstetric ultrasound examinations should be licensed medical practitioners with an understanding of the indications for such imaging studies, the expected content of a complete obstetric ultrasound examination, and a familiarity with the limitations of ultrasound imaging. They should be familiar with ultrasound safety and the anatomy, physiology, and pathophysiology of the pelvis, pregnant uterus, and fetus. All physicians who perform or supervise the performance of obstetric ultrasonography should have received specific training in obstetric ultrasonography.”14
For family medicine residents, longitudinal curricula in obstetric ultrasound examination will allow for acquisition of skill. An individual physician's proficiency typically depends on factors such as time committed, patient volume, and enthusiasm. The International Society of Ultrasound in Obstetrics and Gynecology (ISUOG) concurs, noting that the optimal amount of training and the minimum number of supervised examinations required for competence in obstetric ultrasound examination can vary greatly according to the learner’s predisposition.18
The AAFP recommends that family physicians document all significant training and experience so that this information can be reported in an organized fashion, if necessary.19 Documentation should demonstrate the physician’s understanding of the technology, ability to perform the ultrasound examination, and ability to interpret findings.12 Any family physician who intends to perform obstetric ultrasound examinations is advised to keep a record of the following:
- Courses taken, including the number of hours of formal learning involved
- Number of directly supervised examinations performed
- Total number of examinations performed
- Types of examinations performed (e.g., standard examinations, labor and delivery scans, emergency
department scans, ultrasound-guided procedures)
In addition, the AAFP acknowledges that documentation of outcomes is important to demonstrate proficiency and support credentialing. In the case of obstetric ultrasound examination, specific outcomes that are most likely to be scrutinized include the following:
- Accuracy of gestational age assessment by correlation of eventual delivery date and gestational age
- Accuracy of fetal anatomic survey by follow-up of infants suspected of having fetal anomalies or
those in whom fetal anomalies were missed
Section V – Credentialing and Privileges
Office practice of obstetric ultrasound examination is currently unregulated in the sense that an office-based physician who has ultrasound equipment can use it as he or she sees fit. However, facility accreditation may be required by some payers before payment is issued. The AIUM and ACR both offer ultrasound facility accreditation.20,21 The accreditation system is open to any practice, regardless of specialty, and is based on meeting standard examination content, documentation, procedure volume, and maintenance standards. A study of the AIUM accreditation program found that practices had improved case study scores and compliance with published minimum standards and guidelines for the performance of obstetric ultrasound examinations after three years of accreditation.22
Obstetric ultrasound services provided in hospitals range from standard examinations to emergency department and labor and delivery applications. Standard ultrasound examinations are usually performed in the department of radiology by technical personnel and interpreted and "validated" by radiologists (sonologists). Radiology departments generally guard their control of these studies. A variety of procedural, medical, legal, and financial arguments are raised against allowing non-radiologists access to the radiology department equipment. Therefore, it becomes an interspecialty issue involving family physicians, OB/GYNs, and radiologists.
Since most family physicians who perform obstetric ultrasound examination do so in their office, this may not often pose a significant problem. However, if an office practice and its equipment are owned by a hospital, the radiology department may try to assert its sovereignty over office imaging practice, including plain radiography and diagnostic ultrasound, thus infringing on family physicians' office-based practices. Family medicine residencies could also be affected if they are denied ultrasound equipment based on a radiology department's objections.
It is the position of the AAFP that clinical privileges should be granted on the basis of each individual physician’s documented training and/or experience, demonstrated abilities, and current competence, not on specialty designation alone.23 This general policy applies to performing obstetric ultrasound examinations in the family medicine practice. The AAFP’s policy on interspecialty support in clinical procedures states, "The AAFP should seek to work collaboratively with other specialty societies, when appropriate, concerning issues of procedure skills, including but not limited to: training, privileging and credentialing, and joint political action."24
Section VI – Miscellaneous Issues
A. Quality assurance
Ensuring the quality of CME in ultrasound examination is important. The AAFP Prescribed credit mechanism is one means of ensuring that courses offered by the AAFP or other professional organizations meet quality standards.
B. Public health implications
Family physicians are the first—and sometimes the only—point of contact for many patients within the health care system. Expanding and improving family physicians' use of obstetric ultrasound examination could improve access to care for patient populations in need.25
C. Financial implications
The general financial implications of expanding family physicians' use of obstetric ultrasound examination include the cost savings associated with improved access to care. The implications for practicing physicians include the revenue generated by this procedural skill and the enhanced attractiveness to managed care organizations of practices that can provide more comprehensive services.
D. Research agenda
The research agenda for obstetric ultrasound examination should focus on clearly defining competency-based measures and analyzing outcomes of examinations performed by family physicians.
Section VII – References
1. American Academy of Family Physicians, American College of Obstetricians and Gynecologists. AAFP-ACOG joint statement on cooperative practice and hospital privileges.
http://www.aafp.org/about/policies/all/aafp-acog.html. Accessed April 6, 2018.
2. American Academy of Family Physicians. Recommended curriculum guidelines for family medicine residents. Maternity care. Leawood, Ks: AAFP; 2016. AAFP Reprint No. 261.
print261_Maternity.pdf. Accessed April 6, 2018.
3. American College of Obstetricians and Gynecologists. Health disparities in rural women. Committee Opinion No. 586 (reaffirmed 2016). https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Health-Care-for-Underserved-Women/Health-Disparities-in-Rural-Women(www.acog.org). Accessed April 6, 2018.
4. Tong ST, Makaroff LA, Xierali IM. Proportion of family physicians providing maternity care continues to decline. J Am Board Fam Med. 2012;25(3):270-271.
5. Choosing Wisely®. Don’t perform prenatal ultrasounds for non-medical purposes, for example, solely to create keepsake videos or photographs.
ultrasounds-for-non-medical-purposes/. Accessed April 6, 2018.
6. U.S. Food and Drug Administration. Avoid fetal "keepsake" images, heartbeat monitors.
https://www.fda.gov/ForConsumers/ConsumerUpdates/ucm095508.htm(www.fda.gov). Accessed April 6, 2018.
7. American Academy of Family Physicians. AAFP Member Census, December 31, 2017. Table 12: Clinical procedures performed by physicians at their practice.
https://www.aafp.org/about/the-aafp/family-medicine-facts/table-12(rev).html. Accessed April 6, 2018.
8. Nothnagle M, Sicilia JM, Forman S, et al. Required procedural training in family medicine: a consensus statement. Fam Med. 2008;40(4):248-252.
9. Council of Academic Family Medicine (CAFM). Consensus statement for procedural training in family medicine residency. https://afmrd.socious.com/d/do/966(afmrd.socious.com). Accessed April 6, 2018.
10. American Academy of Family Physicians. Family medicine fellowship directory.
https://nf.aafp.org/Directories/Fellowship/Search. Accessed April 6, 2018.
11. Chang Pecci C, Leeman L, Wilkinson J. Family medicine obstetrics fellowship graduates: training and post-fellowship experience. Fam Med. 2008;40(5):326-332.
12. Deutchman M. Diagnostic ultrasound in labor and delivery. In: Advanced Life Support in Obstetrics Provider Course Syllabus. Leawood, Ks.: American Academy of Family Physicians; 2017.
13. American Institute of Ultrasound in Medicine. AIUM practice guideline for the performance of obstetric ultrasound examinations. J Ultrasound Med. 2013;32(6):1083-1101.
14. American College of Obstetricians and Gynecologists’ Committee on Practice Bulletins—Obstetrics and American Institute of Ultrasound in Medicine. Practice bulletin no. 175: ultrasound in pregnancy. Obstet Gynecol. 2016;128(6):e241-e256.
15. American College of Radiology. ACR–ACOG–AIUM–SRU practice parameter for the performance of obstetrical ultrasound. Reston (VA): ACR; 2013. https://acr.org/-/media/ACR/Files/Practice-Parameters/us-ob.pdf(acr.org). Accessed June 20, 2018.
16. Reddy UM, Abuhamad AZ, Levine D, Saade GR. Fetal imaging: executive summary of a joint Eunice Kennedy Shriver National Institute of Child Health and Human Development, Society for Maternal–Fetal Medicine, American Institute of Ultrasound in Medicine, American College of Obstetricians and Gynecologists, American College of Radiology, Society for Pediatric Radiology, and Society of Radiologists in Ultrasound Fetal Imaging workshop. Obstet Gynecol. 2014;123(5):1070-1082.
17. American College of Obstetricians and Gynecologists. Practice bulletin no. 145: antepartum fetal surveillance. Obstet Gynecol. 2014;124(1):182-192.
18. International Society of Ultrasound in Obstetrics and Gynecology. ISUOG Education Committee recommendations for basic training in obstetric and gynecological ultrasound. Ultrasound Obstet Gynecol. 2014; 43:113-116.
19. American Academy of Family Physicians. Privileges, documentation of training and experience (reviewed and approved 2017). http://www.aafp.org/about/policies/all/privilegesdocumentation.html. Accessed April 6, 2018.
20. American Institute of Ultrasound in Medicine. AIUM ultrasound practice accreditation.
http://www.aium.org/accreditation/accreditation.aspx. Accessed April 6, 2018.
21. American College of Radiology. ACR ultrasound accreditation. https://www.acraccreditation.org/Modalities/Ultrasound. Accessed April 6, 2018.
22. Abuhamad AZ, Benacerraf BR, Woletz P, Burke BL. The accreditation of ultrasound practices: impact on compliance with minimum performance guidelines. J Ultrasound Med. 2004;23(8):1023-1029.
23. American Academy of Family Physicians. Privileging policy statements (reviewed and approved 2017). http://www.aafp.org/about/policies/all/privileges.html. Accessed April 6, 2018.
24. American Academy of Family Physicians. Procedural skills, interspecialty support in clinical procedures (reviewed and approved 2016). http://www.aafp.org/about/policies/all/proceduralskills.html. Accessed April 6, 2018.
25. Cancino R. Primary care issues in inner-city America and internationally. Prim Care. 2017;44(1):21-32.
(2002) (2018 COD)