Results of a study by Colombian investigators underscore the correlation between decreased brain volume on fetal magnetic resonance imaging (MRI) and ultrasound-detected microcephaly in Zika-exposed fetuses. The findings were presented at the 37th Annual Pregnancy Meeting of the Society for Maternal-Fetal Medicine, held in Las Vegas.
The goal of the prospective cohort study was to assess fetal brain findings and volumetric composition with MRI in fetuses with confirmed Zika virus from the current outbreak in Barranquilla, Colombia. Among 214 pregnant women with Zika exposure, 13 fetuses were found on ultrasound to have abnormal brain findings such as microcephaly, ventriculomegaly, callosal dysgenesis, calcifications, and cortical anomalies. Seven women who were Zika-positive received fetal MRI at 29±4.4 weeks and were gestational age matched to 7 healthy controls at 29.87±4.61 weeks.
Total brain volume in the Zika-infected fetuses differed significantly from that in controls (9422.42±2169.11 versus 20529.7±7049.95; P<0.001) as did total intracranial volume (16390.42±3690.41 versus 35593.42±12281.71; P<0.01. No significant difference was seen in ventricular volume, brainstem volume, or cerebellar volume. The ratio of cerebrospinal fluid to supratentorial brain parenchyma was higher in Zika-affected fetuses (1.36±0.20 versus 0.99±0.16; P<0.01), suggesting microcephaly.
Sanz-Cortes M, Zarutskie AJ, Yepez M, et al. Characterization of brain malformations and volume assessment in fetuses with Zika virus infection using MRI. Abstract 73. Presented Friday, January 27 at the 37th Annual Pregnancy Meeting of the Society for Maternal-Fetal Medicine in Las Vegas, Nevada.