Movement Assessment Predicts Neurodevelopmental Outcomes in Infants with Prenatal Zika Exposure

Prenatal Zika virus infection is well known to cause microcephaly and neurological complications, including movement disorders. Researchers in Brazil assessed motor behaviors using general movement assessment (GMA), conducted using video recordings, in 111 infants aged 3 to 5 months post-term (mean, 14 weeks) whose mothers had a febrile infection with a rash during pregnancy at the time of the Zika virus epidemic. Thirty-five of these infants had microcephaly from congenital Zika. In 56 infants without microcephaly whose mothers had confirmed Zika virus infection, researchers also assessed neurodevelopment (Bayley-III score) at 12 months. Results were compared with 333 matched healthy controls. Results were as follows:

• Fidgety movements (global GMA measure) were normal in all 333 control infants, in none of the infants with microcephaly, and in 64 of 76 infants (84%) without microcephaly (3 had abnormally exaggerated fidgety movements and 9 had no fidgety movements).

• Abnormal fidgety movements were more common when maternal infection occurred in the first trimester.

• Abnormal or no fidgety movements were observed in 16% of infants with prenatal exposure to Zika infection. This rate was similar regardless of whether mothers tested positive (n=56) or negative (n=20) for Zika.

• Most Zika-exposed infants (82%) had normal Bayley-III scores at 12 months. None of those with normal Bayley scores had abnormal fidgety movements at 14 weeks. Seven of the 10 with abnormal Bayley-III scores at 12 months had abnormal fidgety movements at 14 weeks.

• The GMA at 14 weeks had sensitivity of 70%, specificity of 96%, and overall accuracy of 91% for predicting normal neurodevelopment at 12 months.