A few years ago, I met a mom who delivered a baby girl with severe IUGR. She had traveled to southern Florida for a wedding during her first trimester of pregnancy. Given her baby’s growth restriction and the travel history, there was concern that she may have contracted Zika virus and transmitted it to her daughter in utero. She was understandably anxious and sad.
The Zika epidemic in Brazil, the Americas, and beyond in 2015-2016 posed a major threat to pregnant women and their unborn children. Pregnant women were advised to avoid travel to areas with risk of Zika, and pregnant women living in these areas needed to take sufficient precautions to avoid becoming infected.
Although the circulation of Zika virus has decreased significantly since the outbreak in 2015-2016, it continues to remain a threat in the future, as mosquitoes that transmit Zika populate many areas across the globe, and there is still no vaccine. While it had been established that babies infected with Zika virus in utero are at increased risk for IUGR and microcephaly, many questions about the virus and its effects remained unanswered.
A 2019 study published in JAMA Network Open sought to determine if there is an association between General Movement Assessment (GMA) results and later neurodevelopment in infants prenatally exposed to Zika. The GMA is an observational assessment used to classify motor function in the early weeks of life, and results have been shown to be predictive of later developmental outcome. The presence of fidgety movements on the GMA predicts a normal neurodevelopmental outcome, while an absence of fidgety movements predicts adverse outcome. Researchers also generated a Motor Optimality Score based on overall quality of motor repertoire.
The study enrolled 444 infants, 111 who were exposed to maternal illness with rash, and 333 without exposure. Participants were evaluated using the GMA at 9-20 weeks post term age, and the Bayley Scales of Infant and Toddler Development III at 12 months of age. Of the infants with prenatal exposure, 35 developed microcephaly. None of these 35 infants demonstrated fidgety movements on the GMA. In contrast, all 333 healthy controls did demonstrate fidgety movements. The children who developed microcephaly did not participate in developmental testing at 12 months because they all had spastic cerebral palsy, and were unable to maintain antigravity head and trunk postures in prone and sitting, and could not independently roll. Zika exposed infants who did not develop microcephaly still scored lower on the Motor Optimality Score than neurotypical controls, and 15.8% had abnormal fidgety movements. At 12 months, 82% of these children were considered healthy.
This study demonstrates that the GMA is a valuable assessment in evaluating infants congenitally exposed to Zika virus. Importantly, this study revealed that while many children exposed to Zika without microcephaly are developing normally at 12 months of age, a percentage of them do present with delays. Therefore, the study authors recommend routine use of the GMA for infants exposed to Zika in order to facilitate timely referrals to therapy. Neonatal therapists can play a major part in maximizing developmental outcome for infants exposed to Zika prenatally, and timely evaluation is key.
Einspieler, C., Utsch, F., Brasil, P., Aizawa, C., Peyton, C., Hasue, R., et al. (2019). Association of infants exposed to prenatal zika virus infection with their clinical, neurologic, and developmental status evaluated via the general movement assessment tool. Jama Network Open, 2(1):e187235
Abstract and link to full text article available at: https://jamanetwork.com/journals/jamanetworkopen/article-abstract/2720922