Conference Coverage

Fetal MRI may change pregnancy management



CHARLOTTE, N.CFetal MRI and consultation with a neurologist make significant contributions to the fetal diagnosis of posterior fossa anomalies, according to research presented at the annual meeting of the Child Neurology Society. This imaging technique and neurologic consultation complement the information that prenatal ultrasound and obstetric consultations provide and may influence pregnancy management and infant neurologic care significantly.

The fetal diagnosis of posterior fossa abnormalities can be challenging. The prognosis can vary greatly, depending on the diagnosis. Sarah Mulkey, MD, PhD, director of the fetal and neonatal fellowship and a fetal and neonatal neurologist at Children’s National in Washington, and colleagues conducted an analysis to evaluate whether fetal MRI and neurology consultation produce alternative diagnoses for maternal-fetal dyads who are referred to a fetal neurology program because of concern for a fetal posterior fossa anomaly. The researchers also sought to determine how often the postnatal evaluation differed from the fetal diagnosis.

Dr. Mulkey and colleagues retrospectively analyzed cases referred to the Fetal Medicine Institute at Children’s National from January 2012 to June 2018. They included the referral diagnoses of Dandy-Walker continuum, cerebellar hypoplasia, vermis hypoplasia, Blake’s pouch cyst, mega cisterna magna, and other posterior fossa anomalies in their study.

The investigators identified 188 cases that had undergone fetal MRI and neurology consultation. The average gestational age at evaluation was 25 weeks, and the average maternal age was 30 years. Approximately 43% of referrals resulted from a concern regarding Dandy-Walker malformation, and 21% of referrals resulted from a suspicion of mega cisterna magna.

Fetal MRI and neurology consultation resulted in a change from the referral diagnosis or additional information about the fetus in 124 (66%) cases. For example, after imaging and consultation, 15% of referrals were diagnosed with Dandy-Walker malformation, as opposed to the 43% who were suspected of having it. Most referrals with a diagnosis of vermis hypoplasia had a better prognosis after fetal MRI. Fetal MRI and consultation also resulted in new diagnoses of Joubert syndrome and rhombencephalosynapsis. About 19% of referrals were considered normal. “A considerable number of these referrals ended up being for conditions that would have a good outcome,” said Dr. Mulkey.

In addition, the researchers obtained the postnatal diagnosis for 60 of 138 (43%) live-born infants. The fetal diagnosis of Dandy-Walker continuum was confirmed post natally in six of six (100%) cases. Of the 13 cases of fetally diagnosed vermis hypoplasia, 7 (54%) had stable findings, 3 (23%) normalized, and diagnosis changed in 3 (23%). Of the 17 fetally diagnosed Blake’s pouch cysts, 8 (47%) remained stable, 5 (29%) normalized, and diagnosis changed in 4 (24%). Four of nine (44%) cases of fetally diagnosed mega cisterna magna remained stable, two (22%) normalized, and diagnosis changed in three (33%). Overall, prognosis did not change after postnatal imaging.

“There is a high degree of correlation between fetal and postnatal diagnoses for Dandy-Walker continuum, cerebellar hypoplasia, cyst, and ‘other’ diagnoses,” said Dr. Mulkey. “Vermis hypoplasia and Blake’s pouch cyst diagnoses were less consistent.”

The investigators reported no disclosures.

SOURCE: Schlatterer S et al. CNS 2019, Abstract 158.

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