Children exposed to maternal COVID-19 during pregnancy showed lower birth weight, lower birth BMI, and accelerated postnatal weight gain, compared with those unexposed.
New research suggests Infants exposed in utero to maternal COVID-19 infection experienced lower birth weight and body mass index (BMI), but accelerated postnatal weight gain, compared with unexposed counterparts.1
The investigative team from Massachusetts General Hospital indicate the accelerated growth trajectory displayed by children exposed to maternal COVID-19 may be linked to adverse cardiometabolic outcomes, including obesity and cardiovascular disease (CVD), in later life.
“Our findings suggest that children exposed in utero to maternal COVID-19 have an altered growth pattern in early life that may increase their risk of obesity, diabetes, and cardiovascular disease over time,” said Lindsay T. Fourman, MD, Massachusetts General Hospital.2 “There is still a lot of research needed to understand the effects of COVID-19 on pregnant women and their children.”
The outbreak of COVID-19 and pregnant women making up 9% of reproductive-aged women with infection led to the emergence of a novel population of children with in utero exposure. However, there is little knowledge on the potential impact of maternal COVID-19 in pregnancy on the health of the offspring and in particular, their cardiometabolic disease risk.
The current study utilized the Mass General Brigham COVID-19 Perinatal Biorepository of mothers with and without prenatal COVID-19 and their offspring to examine the association of in utero COVID-19 exposure with weight, length, and BMI z-score trajectories over the first 12 months of life. The analysis focused on the subset of infants born to mothers who delivered prior to June 2021 to ensure that all babies would be ≥12 months of age at time of data collection.
Based on these criteria, a total of 149 babies with in utero exposure to maternal COVID-19 and 127 babies without known exposure born between March 2020 – May 2021 were analyzed. Investigators abstracted weight, length, and BMI from health records at 0, 2, 6, and 12 months and standardized based on growth charts from the World Health Organization. Due to the hypothesis that in utero exposure would be associated with accelerated growth over the first year of life, the prespecified primary endpoint was change in BMI z-score from birth to 12 months.
In linear mixed effects models, those born with prenatal COVID-19 exposure exhibited substantially different trajectories in weight and BMI z-scores over the first year of life compared with unexposed controls (P <.0001). There were no differences observed in length z-score trajectories by COVID-19 exposure status, according to the investigative team.
For the primary endpoint, results suggested infants with in utero COVID-19 exposure had a significantly greater cumulative gain in BMI z-score vs. unexposed controls from birth to 12 months (0.62 ± 1.44 vs −0.05 ± 1.50, P = .001). In an adjusted model, the change remained significantly higher in those born to mothers with prenatal COVID-19 (effect size, 0.53; 95% confidence interval [CI], 0.06 to 0.99).
The analysis additionally evaluated whether lower birth weight z-score may determine the link between in utero COVID-19 exposure and accelerated postnatal growth in infancy. A meditation analysis revealed birth weight z-score mediated a significant proportion of the relationship between COVID-19 exposure and postnatal growth (estimate ± SE, 32 ± 14%, P = .02).
Investigators suggest that the exaggerated growth pattern among infants with COVID-19 exposure may be a catch-up response to a prenatal growth deficit and the potential for an increased cardiometabolic disease risk supports the need for long-term monitoring.
“Our findings emphasize the importance of long-term follow-up of children exposed in utero to maternal COVID-19 infection, as well as widespread implementation of COVID-19 prevention strategies among pregnant individuals,” said Andrea G. Edlow, MD, Massachusetts General Hospital.2 “Larger studies with longer follow-up duration are needed to confirm these associations.”