Lower early motor scores after antenatal COVID-19 exposure
Infants exposed to maternal COVID-19 during pregnancy scored lower on early neuromotor testing than matched prepandemic controls in a longitudinal cohort that followed children in Los Angeles and Rio de Janeiro. The signal appeared on the Motor Optimality Score Revised assessment performed at 3 to 5 months post-term age, where exposed infants had a median score of 23 compared with 25 among controls. Those medians sit close together on paper, yet in early neurodevelopment even modest shifts can matter because spontaneous movement quality reflects the integrity of emerging motor circuits, posture, and the infant’s capacity to organize complex behavior.
The cohort enrolled 239 infants in total. Investigators included 124 exposed cases and 115 controls, and GMA videos were actually assessed in 115 cases and 115 controls. Twenty-five percent of the infants were preterm, a detail that is clinically important because prematurity can blur developmental interpretation and raise the baseline risk of altered motor repertoire. Cases were matched with prepandemic neurotypical unexposed controls from the Graz University Database by gestational age, gender, and post-term age, creating a comparison that was designed to isolate antenatal infection from the usual noise of neonatal heterogeneity.
Antenatal infection does not automatically translate into injury, but it creates a biologically plausible pathway for altered early neurodevelopment. Maternal SARS-CoV-2 infection can trigger systemic inflammation, placental stress, and transient disturbances in the intrauterine environment, all of which may influence fetal brain development during a period when cortical-subcortical motor networks are still assembling. In that setting, the general movement assessment is not a trivial screening exercise. It is a bedside window into the architecture of the developing nervous system.
What the cohort measured and why it matters
The study was built around two linked time points. General movement assessment videos were collected between 3 and 5 months post-term age, and clinical assessments with developmental milestone evaluation followed at 6 to 8 months of age. The primary motor readout was the MOS-R, a structured scoring system that captures the quality and complexity of infant movement. The second endpoint focused on the presence of developmental delay later in infancy, extending the inquiry beyond a single snapshot and into whether early motor differences might correspond to broader developmental vulnerability.
The exposed infants were recruited from hospital-based settings in the United States and Brazil between March 2020 and December 2021, a period when maternal infection patterns, hospital visitor restrictions, and perinatal care delivery were all changing under pandemic pressure. Those real-world conditions matter because they can affect both enrollment and infant follow-up, but they also make the cohort clinically recognizable. These were not idealized laboratory conditions; they were the circumstances in which pediatricians and neonatologists actually cared for children born during the pandemic.
The median MOS-R of 23 in exposed infants, compared with 25 in controls, points toward a shift in movement quality rather than a dramatic collapse in function. In early infancy, that distinction is meaningful. Subtle changes in repertoire complexity may reflect altered motor adaptability, reduced fluency, or less varied spontaneous movement, which can be the earliest sign of downstream developmental differences. The observation also fits the rationale behind using general movements in the first place: before formal milestones or school-age testing, movement patterns often reveal whether the nervous system is maturing in a typical way.
Interpreting the motor signal without overreading it
A lower median score does not establish causation, and it does not mean every exposed infant had impairment. The comparison also depends on who was assessed, how illness severity varied across pregnancies, and whether maternal infection coincided with fever, hospitalization, hypoxia, or other complications that could modify fetal exposure. Still, the finding is hard to ignore because it emerged in a matched cohort and used a validated neurological method rather than a loose developmental impression.
The use of prepandemic controls from a database also gives the study a practical advantage. It reduces the possibility that pandemic-era stressors alone explain the result. At the same time, it raises an obvious clinical question: whether the difference reflects the viral illness itself, the inflammatory response it produced, or the broader perinatal context surrounding infection. For neonatologists and developmental pediatricians, those mechanisms are not academic. They guide follow-up intensity, early intervention referral, and parental counseling.
One sentence captures the bedside relevance: early neuromotor differences can be visible before routine milestone screening would detect them.
The abstract also makes clear that the investigators set out to evaluate developmental milestones at 6 to 8 months, but the scraped record provides only the motor-score result in the early infancy window. Without the full endpoint data, the safest interpretation is narrow. Maternal COVID-19 during pregnancy was associated with lower early neuromotor repertoire scores in this cohort, and the finding justifies close developmental surveillance in exposed infants, especially those born preterm or with other perinatal risk factors.
Why pediatric follow-up still matters
The practical consequence is straightforward: infants with antenatal exposure to COVID-19 should not be dismissed as routine if early motor quality looks off. The general movement exam offers a low-burden way to detect subtle neurological deviation before more obvious delays emerge. In a pandemic cohort spanning two countries and more than two years of enrollment, that kind of signal deserves attention precisely because it appears before the child reaches the age when delays become easier to label but harder to reverse.
Even so, the study remains centered on an early neurodevelopmental marker rather than a hard functional endpoint. The clinical value lies in what happens next. Children with lower MOS-R scores may need closer longitudinal surveillance, repeat developmental screening, and a lower threshold for referral if milestone acquisition slows. The data support vigilance, not panic, and they leave open the more important question of whether these early differences persist, improve, or disappear as children mature beyond infancy.