Multiple Gestations

Variant: 1   Known or suspected multiple gestations. Monochorionic or dichorionic. First trimester. Initial imaging.
Procedure Appropriateness Category
US pregnant uterus transabdominal Usually Appropriate
US pregnant uterus transvaginal Usually Appropriate
US assessment for TTTS Usually Not Appropriate
US cervix transvaginal Usually Not Appropriate
US duplex Doppler fetal middle cerebral artery Usually Not Appropriate
US duplex Doppler fetal umbilical artery Usually Not Appropriate
US echocardiography fetal Usually Not Appropriate
US pregnant uterus biophysical profile Usually Not Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate
MRI fetal without IV contrast Usually Not Appropriate
Variant: 2   Multiple gestations. Monochorionic or dichorionic. First trimester. First trimester ultrasound performed. Next imaging study.
Procedure Appropriateness Category
US pregnant uterus transabdominal Usually Appropriate
US pregnant uterus transvaginal Usually Appropriate
US cervix transvaginal May Be Appropriate
US echocardiography fetal May Be Appropriate
US assessment for TTTS Usually Not Appropriate
US duplex Doppler fetal middle cerebral artery Usually Not Appropriate
US duplex Doppler fetal umbilical artery Usually Not Appropriate
US pregnant uterus biophysical profile Usually Not Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate
MRI fetal without IV contrast Usually Not Appropriate
Variant: 3   Multiple gestations. Dichorionic twins or multichorionic higher order multiples. Second trimester anatomy examination. Follow-up imaging.
Procedure Appropriateness Category
US cervix transvaginal Usually Appropriate
US echocardiography fetal Usually Appropriate
US pregnant uterus transabdominal Usually Appropriate
US duplex Doppler fetal umbilical artery May Be Appropriate
US pregnant uterus transvaginal May Be Appropriate
US assessment for TTTS Usually Not Appropriate
US duplex Doppler fetal middle cerebral artery Usually Not Appropriate
US pregnant uterus biophysical profile Usually Not Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate
MRI fetal without IV contrast Usually Not Appropriate
Variant: 4   Multiple gestations. Monochorionic twins. Second trimester anatomy examination. Follow-up imaging.
Procedure Appropriateness Category
US assessment for TTTS Usually Appropriate
US cervix transvaginal Usually Appropriate
US duplex Doppler fetal umbilical artery Usually Appropriate
US echocardiography fetal Usually Appropriate
US pregnant uterus transabdominal Usually Appropriate
US duplex Doppler fetal middle cerebral artery May Be Appropriate
US pregnant uterus transvaginal May Be Appropriate
MRI fetal without IV contrast May Be Appropriate
US pregnant uterus biophysical profile Usually Not Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate
Variant: 5   Multiple gestations. Dichorionic twins or multichorionic higher order multiples. Growth and antepartum surveillance.
Procedure Appropriateness Category
US pregnant uterus transabdominal Usually Appropriate
US cervix transvaginal May Be Appropriate
US duplex Doppler fetal middle cerebral artery May Be Appropriate
US duplex Doppler fetal umbilical artery May Be Appropriate
US echocardiography fetal May Be Appropriate
US pregnant uterus biophysical profile May Be Appropriate
US pregnant uterus transvaginal May Be Appropriate
US assessment for TTTS Usually Not Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate
MRI fetal without IV contrast Usually Not Appropriate
Variant: 6   Multiple gestations. Monochorionic twins. Growth and antepartum surveillance.
Procedure Appropriateness Category
US assessment for TTTS Usually Appropriate
US duplex Doppler fetal middle cerebral artery Usually Appropriate
US duplex Doppler fetal umbilical artery Usually Appropriate
US pregnant uterus transabdominal Usually Appropriate
US cervix transvaginal May Be Appropriate
US echocardiography fetal May Be Appropriate
US pregnant uterus biophysical profile May Be Appropriate
US pregnant uterus transvaginal May Be Appropriate
MRI fetal without IV contrast May Be Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate
Variant: 7   Multiple gestations. Dichorionic or multichorionic higher order multiples or monochorionic gestations. Known abnormality or discordance between fetuses (fluid, size, weight). Growth and antepartum surveillance.
Procedure Appropriateness Category
US duplex Doppler fetal middle cerebral artery Usually Appropriate
US duplex Doppler fetal umbilical artery Usually Appropriate
US pregnant uterus biophysical profile Usually Appropriate
US pregnant uterus transabdominal Usually Appropriate
US assessment for TTTS May Be Appropriate
US cervix transvaginal May Be Appropriate
US echocardiography fetal May Be Appropriate
US pregnant uterus transvaginal May Be Appropriate
MRI fetal without IV contrast May Be Appropriate
MRI fetal without and with IV contrast Usually Not Appropriate

The evidence table, literature search, and appendix for this topic are available at https://acsearch.acr.org/list. The appendix includes the strength of evidence assessment and the final rating round tabulations for each recommendation.

For additional information on the Appropriateness Criteria methodology and other supporting documents, please visit https://www.acr.org/Clinical-Resources/Clinical-Tools-and-Reference/Appropriateness-Criteria.

Appropriateness Category Name

Appropriateness Rating

Appropriateness Category Definition

Usually Appropriate

7, 8, or 9

The imaging procedure or treatment is indicated in the specified clinical scenarios at a favorable risk-benefit ratio for patients.

May Be Appropriate

4, 5, or 6

The imaging procedure or treatment may be indicated in the specified clinical scenarios as an alternative to imaging procedures or treatments with a more favorable risk-benefit ratio, or the risk-benefit ratio for patients is equivocal.

May Be Appropriate (Disagreement)

5

The individual ratings are too dispersed from the panel median. The different label provides transparency regarding the panel’s recommendation. “May be appropriate” is the rating category and a rating of 5 is assigned.

Usually Not Appropriate

1, 2, or 3

The imaging procedure or treatment is unlikely to be indicated in the specified clinical scenarios, or the risk-benefit ratio for patients is likely to be unfavorable.

Potential adverse health effects associated with radiation exposure are an important factor to consider when selecting the appropriate imaging procedure. Because there is a wide range of radiation exposures associated with different diagnostic procedures, a relative radiation level (RRL) indication has been included for each imaging examination. The RRLs are based on effective dose, which is a radiation dose quantity that is used to estimate population total radiation risk associated with an imaging procedure. Patients in the pediatric age group are at inherently higher risk from exposure, because of both organ sensitivity and longer life expectancy (relevant to the long latency that appears to accompany radiation exposure). For these reasons, the RRL dose estimate ranges for pediatric examinations are lower as compared with those specified for adults (see Table below). Additional information regarding radiation dose assessment for imaging examinations can be found in the ACR Appropriateness Criteria® Radiation Dose Assessment Introduction document.

Relative Radiation Level Designations

Relative Radiation Level*

Adult Effective Dose Estimate Range

Pediatric Effective Dose Estimate Range

O

0 mSv

 0 mSv

☢

<0.1 mSv

<0.03 mSv

☢☢

0.1-1 mSv

0.03-0.3 mSv

☢☢☢

1-10 mSv

0.3-3 mSv

☢☢☢☢

10-30 mSv

3-10 mSv

☢☢☢☢☢

30-100 mSv

10-30 mSv

*RRL assignments for some of the examinations cannot be made, because the actual patient doses in these procedures vary as a function of a number of factors (e.g., region of the body exposed to ionizing radiation, the imaging guidance that is used). The RRLs for these examinations are designated as “Varies.”
























































































The ACR Committee on Appropriateness Criteria and its expert panels have developed criteria for determining appropriate imaging examinations for diagnosis and treatment of specified medical condition(s). These criteria are intended to guide radiologists, radiation oncologists and referring physicians in making decisions regarding radiologic imaging and treatment. Generally, the complexity and severity of a patient’s clinical condition should dictate the selection of appropriate imaging procedures or treatments. Only those examinations generally used for evaluation of the patient’s condition are ranked.  Other imaging studies necessary to evaluate other co-existent diseases or other medical consequences of this condition are not considered in this document.  The availability of equipment or personnel may influence the selection of appropriate imaging procedures or treatments. Imaging techniques classified as investigational by the FDA have not been considered in developing these criteria; however, study of new equipment and applications should be encouraged.  The ultimate decision regarding the appropriateness of any specific radiologic examination or treatment must be made by the referring physician and radiologist in light of all the circumstances presented in an individual examination