Clinical UM Guideline

This document addresses the use of maternity ultrasound in the outpatient setting.

Note: This document does not address the measurement of nuchal translucency.

Note: Please see the following related document for additional information:

• CG-MED-84 Non-Obstetric Gynecologic Duplex Ultrasonography of the Abdomen and Pelvis in the Outpatient Setting
• RAD.00038 Use of 3-D, 4-D or 5-D Ultrasound in Maternity Care

Medically Necessary:

Maternity ultrasound is considered medically necessary for any of the following:

• Routine anatomy screen and dating:
  • One ultrasound of a pregnant uterus per member, per routine course of care;
  • Estimate gestational age for individuals with uncertain clinical dates.
• Known or suspected abnormality of maternal reproductive structure:
  • Clinical suspicion of cervical insufficiency (for example, abnormal cervix on physical examination, maternal history of second trimester pregnancy loss, prior cervical surgery, and diethylstilbestrol [DES] exposure);
  • To assess cervical length in the second or third trimester in individuals with a history of one or more pregnancy losses in the second or early third trimester or in individuals who have had preterm labor in the current pregnancy or in multi-fetal pregnancies;
  • Provide guidance for cervical cerclage placement;
  • Confirm suspected anatomical uterine abnormality, including fibroid uterus;
  • Localization of intrauterine device (IUD);
  • Evaluate a pelvic mass that has been detected clinically.
• Known or suspected abnormality of fetus:
  • Assess significant discrepancy between uterine size and dates;
  • Follow-up for observation of identified fetal or cord anomaly;
  • Evaluate suspected fetal growth abnormality (either growth restriction or macrosomia), and to follow proven or suspected intrauterine growth restriction;
  • Confirm suspected or follow confirmed diagnosis of polyhydramnios or oligohydramnios;
  • Estimate fetal weight or presentation in premature rupture of membranes or preterm labor;
  • Confirm suspected multiple gestation;
  • Serial evaluation of fetal growth in multi-fetal pregnancy. The most relevant clinical information is obtained when serial exams are done at least three weeks apart, beginning no earlier than 18 weeks gestation. In the case of monochorionic twins, one scan per two weeks in the third trimester is considered medically necessary;
  • For twin-twin transfusion syndrome, one scan per week and serial exams, more than once per week, beginning once the diagnosis of monochorionic twins or twin-twin transfusion is made;
  • Confirm suspected abnormal fetal position or presentation;
  • As an adjunct to external version from breech to vertex presentation;
  • A known or suspected exposure to Zika virus.
• Known or suspected abnormality of placenta:
  • Assess placental location associated with vaginal bleeding;
  • Suspected abruptio placenta;
  • Follow-up of subchorionic hematoma;
  • Suspected abnormal placental attachment (placenta accreta);
  • Suspected retained placenta or products of conception.
• Fetal viability or well-being:
  • Evaluate for threatened, incomplete, or missed abortion;
  • Evaluation of decreased fetal movement;
  • Non-reassuring fetal heart rate monitoring;
  • Suspected fetal death;
  • Assess amniotic fluid volume in post-term gestation.
• Other high risk conditions:
  • Assess vaginal bleeding of undetermined etiology;
  • Assess abdominal or pelvic pain of undetermined etiology;
  • Evaluation of fetal condition in late registrants for prenatal care;
  • History of unexplained fetal demise in a previous pregnancy;
  • Assess the fetus in cases with maternal risk factors such as family history of congenital abnormalities, chronic systemic disease (including but not limited to, hypertension, diabetes or sickle cell disease), preeclampsia, substance abuse or hyperemesis gravidarum;
  • Assessment of fetus after abnormal serum Alpha Fetal Protein (AFP), serum screen or multiple analyte serum screen, or cell-free fetal deoxyribonucleic acid (DNA) screening for aneuploidy;
  • Suspected ectopic pregnancy or hydatidiform mole, and to follow hydatidiform mole;
  • Assess the fetus in cases of Rhesus (Rh) isoimmunization and other causes of fetal hydrops;
  • Provide guidance for other testing, such as amniocentesis, chorionic villus sampling, and cordocentesis or procedures such as intrauterine blood transfusions or other in-utero fetal therapeutic procedures.

Not Medically Necessary:

Maternity ultrasound is considered not medically necessary for:

• Assessment of fetal well being, in the absence of the signs, symptoms, or conditions listed above;
• Only sex determination of the fetus;
• Providing a keepsake picture of the baby for the parents.

The following codes for treatments and procedures applicable to this guideline are included below for informational purposes. Inclusion or exclusion of a procedure, diagnosis or device code(s) does not constitute or imply member coverage or provider reimbursement policy. Please refer to the member's contract benefits in effect at the time of service to determine coverage or non-coverage of these services as it applies to an individual member.

When services are Medically Necessary for routine anatomy screen and dating when criteria are met:

When services may be Medically Necessary when criteria are met for known or suspected abnormality of maternal reproductive structure, fetus, or placenta, or fetal viability or other high-risk conditions:
For the procedure codes listed above for the following diagnoses

When services are Not Medically Necessary:
For the procedure and diagnosis codes listed above when criteria are not met or for all other diagnoses not listed; or when the code describes a procedure or situation designated in the Clinical Indications section as not medically necessary.

Ultrasound imaging, also called ultrasound scanning or sonography, is a method of obtaining images of internal organs by sending high-frequency sound waves into the body. The sound wave echoes are recorded and displayed as a real-time visual image. No ionizing radiation (x-ray) is used in ultrasound imaging. Ultrasound during pregnancy is used to assess the uterus, umbilical cord and placenta, as well as fetal anatomy and fetal well-being. Ultrasound imaging can be used after delivery to evaluate abnormalities of the reproductive and adjacent structures.

The American College of Obstetricians and Gynecologists (ACOG) 2016 Practice Bulletin Ultrasound in Pregnancy lists the following recommendations:

The following conclusions are based on good and consistent evidence (Level A):

• At various gestational ages, ultrasound examination is an accurate method of determining gestational age, fetal number, viability, and placental location, and it is recommended for all pregnant patients.

The following conclusions are based on limited or inconsistent evidence (Level B):

• Assessment of chorionicity is most accurate early in pregnancy and, because of the increased rate of complications associated with monochorionicity, determination of chorionicity by the late first trimester or early second trimester is important for counseling and caring for women with multifetal pregnancies.
• An abnormal finding on second-trimester ultrasonography that identifies a major congenital anomaly significantly increases the risk of genetic abnormality and warrants further counseling, including the discussion of various prenatal testing strategies.
• When a growth disturbance is suspected clinically or there is a medical or obstetric condition that increases the risk of a growth disturbance, ultrasonography is the modality of choice to identify abnormal fetal growth.

The following conclusion and recommendation are based primarily on consensus and expert opinion (Level C):

• In the absence of specific indications, the optimal time for a single ultrasound examination is at 18–22 weeks of gestation.
• In the obese patient, expectations regarding visualization of fetal anatomy should be tempered.
• Subtle second-trimester ultrasound markers should be interpreted in the context of a background risk based on the patient’s age, history, genetic screening, and serum screening results.
• The benefits and limitations of ultrasonography should be discussed with all patients.

The American College of Radiology (ACR), the American Institute of Ultrasound in Medicine (AIUM), ACOG, the Society for Maternal Fetal Medicine (SMFM), and the Society of Radiologists in Ultrasound (SRU) practice parameter (2018) notes:

A standard obstetrical ultrasound examination in the first trimester includes evaluation of the presence, size, location, and number of gestational sac(s). The gestational sac is examined for the presence of yolk sac and embryo/fetus (a fetus is generally defined as greater than or equal to 10 weeks gestational age). When an embryo/fetus is detected, it should be measured, and the cardiac activity should be recorded by 2-D video clip or M-mode. The routine use of pulsed Doppler ultrasound to either document or “listen” to embryonic/fetal cardiac activity is discouraged. The uterus, cervix, adnexa, and cul-de-sac region should be examined.

An obstetrical ultrasound in the second or third trimester includes an evaluation of fetal number, cardiac activity, presentation, amniotic fluid volume, placental position, fetal biometry, and an anatomic survey. The maternal cervix and adnexa should be examined.

Zika virus was first reported in South America in May 2015 and has subsequently appeared in the United States. In 2016, ACOG and the SMFM released a practice advisory regarding the current information and recommendations regarding the Zika virus. The recommendations were based on limited data.

The 2017 Centers for Disease Control and Prevention (CDC) interim guidance for the diagnosis, evaluation and management of infants with potential Zika virus infection notes the following:

Questions remain about optimal timing of ultrasound among pregnant women with possible maternal Zika virus exposure. Abnormalities have been detected anywhere from 2 to 29 weeks after symptom onset; therefore, insufficient data are available to define the optimal timing between exposure and initial sonographic screening. Brain abnormalities associated with congenital Zika syndrome have been identified by ultrasound in the second and third trimesters in published case reports. Currently, the negative predictive value of serial normal prenatal ultrasounds is unknown. Serial ultrasound monitoring can detect changes in fetal anatomy, particularly neuroanatomy, and growth patterns.

However, there are no data specific to congenital Zika virus infection to guide these timing recommendations; clinicians may consider extending the time interval between ultrasounds in accordance with patient preferences and clinical judgment. Women with possible exposure but without laboratory evidence of Zika virus infection during pregnancy should receive ultrasound screening as recommended for routine prenatal care. Future data will be used to inform the optimal timing and frequency of ultrasound in pregnant women with possible Zika virus infection.

The 2021 CDC guideline on the treatment of sexually transmitted infections includes management recommendations for individuals who are diagnosed with syphilis in the second half of pregnancy. In addition to treatment, these individuals should undergo a sonographic fetal evaluation to evaluate for signs of fetal or placental syphilis.

While there is no reliable evidence to support ultrasounds performed during pregnancy will harm a fetus, there is general agreement that the casual use of ultrasonography during pregnancy should be avoided (ACOG, 2018). The 2018 ACR/AIUM/ACOG/SMFM/SRU practice parameter notes “Obstetrical ultrasound should be performed only when there is a valid medical reason, and the lowest possible ultrasonic exposure settings should be used to gain the necessary diagnostic information.”

Nuchal translucency: A collection of fluid under the skin at the back of the neck that appears translucent (clear, also known as hypoechoic). This is measured by ultrasound as a prenatal screening test in the late first trimester of pregnancy, often in combination with measurement of maternal serum beta-human chorionic gonadotropin (total beta-hCG or free beta-hСG subunit) and maternal serum pregnancy-associated plasma protein A (PAPP-A). Nuchal translucency that is thicker than normal can be an indicator of chromosomal abnormalities such as Down syndrome (trisomy 21) or other genetic conditions.

Ultrasound: A screening or diagnostic technique in which very high frequency sound waves are passed into the body, and the reflected echoes are detected and analyzed to build a picture of the internal organs or of a single fetus or multiple fetuses in the uterus.

Peer Reviewed Publications:

1. Kaur A, Kaur A. Transvaginal ultrasonography in first trimester of pregnancy and its comparison with transabdominal ultrasonography. J Pharm Bioallied Sci. 2011; 3(3):329-338.
2. Kenkhuis MJA, Bakker M, Bardi F, ET AL. Effectiveness of 12-13-week scan for early diagnosis of fetal congenital anomalies in the cell-free DNA era. Ultrasound Obstet Gynecol. 2018; 51(4):463-469.
3. Poggenpoel EJ, Geerts LT, Theron GB. The value of adding a universal booking scan to an existing protocol of routine mid-gestation ultrasound scan. Int J Gynaecol Obstet. 2012; 116(3):201-205.

Government Agency, Medical Society, and Other Authoritative Publications:

1. Alldred SK, Takwoingi Y, Guo B, et al. First trimester ultrasound tests alone or in combination with first trimester serum tests for Down's syndrome screening. Cochrane Database Syst Rev. 2017; 3:CD012600.
2. American College of Obstetricians and Gynecologists (ACOG). Guidelines for diagnostic imaging during pregnancy and lactation. Committee Opinion 723. Reaffirmed October 2021. Available at: https://www.acog.org/-/media/project/acog/acogorg/clinical/files/committee-opinion/articles/2017/10/guidelines-for-diagnostic-imaging-during-pregnancy-and-lactation.pdf. Accessed on October 17, 2024.
3. ACOG. Obstetric Care Consensus. Placenta Accreta Spectrum. Number 7. Reaffirmed 2021. Available at: https://www.acog.org/clinical/clinical-guidance/obstetric-care-consensus/articles/2018/12/placenta-accreta-spectrum. Accessed on October 17, 2024.
4. ACOG. Practice Bulletins. Available at: https://www.acog.org/clinical/clinical-guidance/practice-bulletin. Accessed on October 17, 2024.
   • Antepartum Fetal surveillance. ACOG Practice Bulletin Number 229. June 2021.
   • Management of preterm labor. ACOG Practice Bulletin Number 171. October 2016.
   • Postpartum hemorrhage. ACOG Practice Bulletin Number 183, October 2017.
   • Screening for Fetal Aneuploidy. ACOG Practice Bulletin 163. Reaffirmed 2018.
   • Ultrasound in pregnancy. ACOG Practice Bulletin 175. December 2016.
5. American College of Radiology (ACR). ACR-ACOG-AIUM-SMFM-SRU Practice parameter for the performance of standard diagnostic obstetrical ultrasound. (Revised 2023). Available at: https://www.acr.org/-/media/ACR/Files/Practice-Parameters/US-OB.pdf . Accessed on October 24, 2024.
6. ACR. ACR Appropriateness Criteria.
   • First Trimester Vaginal Bleeding. Revised 2017. Available at: https://acsearch.acr.org/docs/69460/Narrative/. Accessed on October 24, 2024.
   • Multiple Gestations. Revised 2024. Available at: https://acsearch.acr.org/docs/69462/Narrative/. Accessed on October 24, 2024.
   • Second and Third Trimester Vaginal Bleeding. Revised 2020. Available at: https://acsearch.acr.org/docs/69465/Narrative/?_ga=2.211725906.656052169.1601908671-191399006.1564351312. Accessed on October 24, 2024.
   • Second and third trimester screening for fetal anomaly. New 2020. Available at: https://acsearch.acr.org/docs/3102400/Narrative/. Accessed on October 24, 2024.
7. American Institute of Ultrasound in Medicine (AIUM). AIUM practice guideline for the performance of obstetric ultrasound examinations. J Ultrasound Med 2013; 32(6):1083-1101.
8. AIUM. Official Statements. Available at: https://www.aium.org/resources/official-statements. Accessed on October 24, 2024.
   • Limited obstetrical ultrasound examination. Reapproved June 16, 2020.
   • Prudent use and safety diagnostic ultrasound in pregnancy. Approved May 19, 2020.
   • Statement on Biological Effects of Ultrasound in Vivo. Approved August 19, 2021
9. AUIM. Practice Parameters. Available at: https://www.aium.org/resources/practice-parameters. Accessed on October 24, 2024.
   • AIUM Practice Parameter for the Performance of Detailed Second- and Third-Trimester Diagnostic Obstetric Ultrasound Examinations. November 17, 2019.
   • AIUM Practice Parameter for the Performance of Detailed Diagnostic Obstetric Ultrasound Examinations Between 12 Weeks 0 Days and 13 Weeks 6 Days. August 27, 2020.
   • AIUM Practice Parameter for the Performance of Standard Diagnostic Obstetric Ultrasound. January 15, 2024.
10. Bricker L, Medley N, Pratt JJ. Routine ultrasound in late pregnancy (after 24 weeks' gestation). Cochrane Database Syst Rev. 2015; 2015(6):CD001451.
11. Centers for Disease Control and Prevention (CDC). Accessed on October 24, 2024.
    • Sexually Transmitted Infections Treatment Guidelines, 2021. July 23, 2021. Available at: https://www.cdc.gov/std/treatment-guidelines/STI-Guidelines-2021.pdf.
    • Clinical Testing and Diagnosis for Zika Virus Infections. Updated May 15, 2024. Available at: https://www.cdc.gov/zika/hcp/diagnosis-testing/index.html. 
12. Centers for Medicare and Medicaid Services. National Coverage Determination: Ultrasound diagnostic procedures. NCD #220.5. Revised April 25, 2024. Available at: https://www.cms.gov/Regulations-and-Guidance/Guidance/Manuals/downloads/ncd103c1_part4.pdf. Accessed on October 24, 2024.
13. O'Leary ST, Kimberlin DW. Update From the Advisory Committee on Immunization Practices. J Pediatric Infect Dis Soc. 2017; 6(4):311-316.
14. Papageorghiou AT, Thilaganathan B, Bilardo CM, et al. ISUOG Interim Guidance on ultrasound for Zika virus infection in pregnancy: information for healthcare professionals. Ultrasound Obstet Gynecol. 2016; 47(4):530-532.
15. Society for Maternal-Fetal Medicine (SMFM) Publications Committee. Ultrasound screening for fetal microcephaly following Zika virus exposure. Am J Obstet Gynecol. 2016; 214(6):B2-B4.
16. United States Department of Veterans Affairs / Department of Defense (VA/ DoD). Management of Pregnancy. 2023. Available at: https://www.healthquality.va.gov/guidelines/WH/up/VA-DoD-CPG-Pregnancy-Full-CPG_508.pdf. Accessed on October 24, 2024.
17. Whitworth M, Bricker L, Mullan C. Ultrasound for fetal assessment in early pregnancy. Cochrane Database Syst Rev. 2015; 2015(7):CD007058.

1. American College of Obstetricians and Gynecologists (ACOG). Routine Tests During Pregnancy. FAQ 133, April 2024. Available at: https://www.acog.org/Patients/FAQs/Routine-Tests-During-Pregnancy. Accessed on October 24, 2024.
2. Centers for Disease Control and Prevention (CDC). Birth Defects Homepage: Diagnosis. Updated: May 16, 2024. Available at: https://www.cdc.gov/birth-defects/screening/diagnosis.html.  Accessed on October 24, 2024.
3. Centers for Disease Control and Prevention (CDC). Zika Virus. Updated May 31, 2024. Available at: https://www.cdc.gov/zika/prevention/index.html. Accessed on October 24, 2024.
4. U.S. National Library of Medicine. MedlinePlus. Prenatal ultrasound-series. Reviewed March 31, 2024. Available at: https://medlineplus.gov/ency/presentations/100197_1.htm. Accessed on October 24, 2024.

Maternal Ultrasound
Obstetric
Prenatal
Sonography