Colombia infants exposed to Zika in the womb were found to have both cognitive and motor development delays in the first year and a half of life even if their head circumference was normal at the time of birth.
The study, published in the JAMA Pediatrics journal, involved 70 babies born between August 2016 and November 2017 along the Colombia Caribbean coast. This was an area of South America that saw numerous cases and prompted the World Health Organization to declare a world health emergency.
Mosquitos carry the Zika virus, which can affect pregnant mothers and their unborn babies. In babies, it can lead to disabilities and defects known as congenital Zika syndrome. This syndrome leads to decreased brain tissue, severe microcephaly, clubfoot, eye damage, etc.
While 90 to 95 percent of babies whose mothers were infected with Zika while pregnant have no known birth defects, but it’s not known if this affects their brain development.
Children’s National Hospital Fetal and Neonatal Neurologist Sarah Mulkey said nobody was really concerned about these sets of babies. However, these normal-looking babies are not progressing as they should for their development timelines such as crawling, walking and peekaboo.
The study involved several groups of pregnant women who tested positive for Zika and then chose babies who had no congenital disabilities.
The babies were then assessed two times until 18 months of age using two popular tools:
- Alberta Infant Motor Scale
- Warner Initial Developmental Evaluation of Adaptive and Functional Skills
The majority of babies were subjected to a postnatal cranial ultrasound scan, with 30 percent showing elusive brain abnormalities such as tiny cysts. It was only in less than five percent of the population, which isn’t considered too much of an issue.
In the questionnaire, the researchers discovered babies actually fared worse than average.
Mulkey said the most significant difference was in the mobility scores, which involves finding out the babies’ abilities to roll over, crawl, sit up, walk, climb stairs, etc.
She said there were some notable differences in their cognitive and social scores as well, which determines their ability to play peekaboo or roll a ball.
In the observational motor skills assessments, babies who had minute brain abnormalities did worse than babies who had no defects.
Mulky said the combination of these delays means there is a need for long-term evaluations, a need to do specialized testing to discover if babies with mothers with the Zika virus actually have brain abnormalities not readily apparent.
The report shows the babies look normal at birth but are experiencing notable differences in their growth. Therefore, it’s not known how the Zika virus will affect that at age five or eight in their life because no child has reached these ages yet.
The team wonders if the children’s development is going to worsen or if they will eventually catch up – something they are pondering for the next part of the study.