Description/Background
MRI not only contributes to diagnosis, but it also serves as an important guide to treatment, delivery planning and counseling. However, sonography is the screening modality of choice in the fetus. The advantage of MRI over ultrasound is its ability to image deep soft tissue structures without relying on the skill of the operator or limitations of patient body habitus.

Fetal MRI should be performed only for a valid medical reason and only after careful consideration of sonographic findings or family history of an abnormality for which screening with MRI might be beneficial. Before 18 weeks gestational age, a fetal MRI may not provide additional diagnostic information due to the small size of the fetus and fetal movement when compared with sonography. The need for early diagnosis should be balanced against the advantages of improved resolution later in pregnancy, with the choice dependent on the anomalies to be assessed.

According to the American College of Obstetricians and Gynecologists’ Committee on Obstetric Practice, the preponderance of animal studies demonstrates no risk of teratogenesis to the fetus, and tissue heating from MRI scanners is negligible near the uterus.⁴ Furthermore, in human studies of patients undergoing MRI, there has been no acoustic injuries to the fetus during prenatal MRI.4 At this time there is no documentation of deleterious effects of MRI at 1.5T and 3T on the developing fetus.²
 

Policy 
Fetal MRI is considered MEDICALLY NECESSARY for the following indications:  

• To better define or confirm a known or suspected abnormality of the fetus after ultrasound has been performed during the second trimester or when fetal surgery is planned, and/or to make a decision about therapy, delivery or to advise the family about prognosis.

Safety guidelines and possible contraindications:
There are no documented fetal indications for the use of MRI contrast, but there may be rare instances where contrast is considered potentially helpful in assessing the pregnant patient’s anatomy or pathology.

The decision to administer contrast must be made on a case-by-case basis by the covering level 2 MR personnel-designated attending radiologist who will assess the risk-benefit ratio for that particular patient. The decision to administer a gadolinium-based MR contrast agent to pregnant patients should be accompanied by a well-documented and thoughtful risk-benefit analysis.

All other uses of this technology are investigational and/or unproven and therefore considered NOT MEDICALLY NECESSARY. 

References 

1. American College of Obstetricians and Gynecologists (ACOG). Guidelines for Diagnostic Imaging During Pregnancy and Lactation. ACOG Committee Opinion. 2017 Oct; 723. https://www.acog.org/Clinical-Guidance-and-Publications/Committee-Opinions/Committee-on-Obstetric-Practice/Guidelines-for-Diagnostic-Imaging-During-Pregnancy-and-Lactation.
2. American College of Radiology (ACR) and Society for Pediatric Radiology (SPR). ACR-SPR Practice Parameter for the Safe and Optimal Performance of Fetal Magnetic Resonance Imaging (MRI). https://www.acr.org/-/media/ACR/Files/Practice-Parameters/MR-Fetal.pdf. Revised 2020. Accessed August 19, 2021.
3. Perrone A, Savelli S, Maggi C, et al. Magnetic resonance imaging versus ultrasonography in fetal pathology. Radiol Med. 2008; 113:225-41. http://www.ncbi.nlm.nih.gov/pubmed/18386124.
4. Prayer D, Malinger G, Brugger PC, et al. ISUOG Practice guidelines: Performance of fetal magnetic resonance imaging. Ultrasound Obstet Gynecol. 2017 May; 49(5):671-80.
5. Saleem SN. Fetal MRI: An approach to practice: A review. J Adv Res. 2014; 5:507-523. http://www.ncbi.nlm.nih.gov/pubmed/25685519.
6. Society for Pediatric Radiology (SPR). Fetal MRI – General Information. Revised 2021. Accessed August 19, 2021. http://www.pedrad.org/Specialties/Fetal-Imaging/Fetal-MRI-General-Information.
7. Tocchio S, Kline-Fath B, Kanal E, et al. MRI evaluation and safety in the developing brain. Semin Perinatol. 2015; 39:73-104. http://www.seminperinat.com/article/S0146-0005(15)00003-8/fulltext?mobileUi=0.  

Coding Section 

Procedure and diagnosis codes on Medical Policy documents are included only as a general reference tool for each policy. They may not be all-inclusive. 

This medical policy was developed through consideration of peer-reviewed medical literature generally recognized by the relevant medical community, U.S. FDA approval status, nationally accepted standards of medical practice and accepted standards of medical practice in this community, Blue Cross Blue Shield Association technology assessment program (TEC) and other non-affiliated technology evaluation centers, reference to federal regulations, other plan medical policies, and accredited national guidelines.

"Current Procedural Terminology © American Medical Association. All Rights Reserved" 

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