Background: Prenatal ultrasound is the standard modality to screen for fetal craniofacial malformations, but can be limited by sonographer experience, oligohydramnios, and maternal obesity. Fetal magnetic resonance imaging (MRI) can be used as an adjunct to ultrasound, but there is a paucity of literature on its performance. The objective of this study was to examine the accuracy of fetal MRI for prenatal diagnosis of craniofacial abnormalities in an at-risk patient population and to determine if accuracy is maintained before and after 24 weeks gestational age (GA).
Methods: This was a retrospective review of a single-center fetal MRI database including cases from March 2011 to November 2018. All cases were referred for MRI due to a suspected orofacial cleft or micrognathia upon screening ultrasound. Magnetic resonance imaging was performed and interpreted by dedicated fetal MRI radiologists. Prenatal findings were correlated with postnatal anatomy.
Results: Sixty-one cases were identified. Ten were lost to follow-up and 9 underwent termination of pregnancy. Among the remaining 42 cases, MRI possessed a sensitivity of 91.7% and negative predictive value (NPV) of 90% for prenatal diagnosis of cleft palate. When performed at early GA, fetal MRI (n = 20) demonstrated sensitivity and NPV of 100% for cleft palate diagnosis. For cleft lip, MRI had 93.1% sensitivity and 86.7% NPV without significant decrease in accuracy at early GA. For micrognathia, MRI demonstrated 100% sensitivity and NPV overall, as well as at early and late gestational ages.
Conclusions: Fetal MRI is an accurate method for prenatal diagnosis of cleft palate, cleft lip, and micrognathia. Furthermore, it remains highly accurate even when performed before 24 weeks GA. We advocate the use of fetal MRI as an adjunct imaging modality to standard ultrasound for the evaluation of suspected fetal craniofacial anomalies to provide complete and accurate counseling to prospective parents and facilitate the planning of appropriate postnatal care.