Rapid weight gain (RWG) in infants and the mother’s prepregnancy overweight have a synergistic effect in increasing the odds that a child will develop overweight or obesity, new research suggests.
Findings were published online in Pediatrics.
Each factor has independently been associated with higher risk of childhood obesity but whether the two factors together exacerbate the risk has not been well studied, according to the authors led by Stephanie Gilley, MD, PhD, department of pediatrics, section of nutrition, University of Colorado at Denver, Aurora.
“Pediatric providers should monitor infants for RWG, especially in the context of maternal obesity, to reduce future risk of obesity,” the authors conclude.
Dr. Gilley’s team studied mother-infant dyads (n = 414) from the Healthy Start Study, an observational prebirth cohort. RWG was defined as a weight-for-age z score increase of at least 0.67 from birth to 3-7 months.
They found that RWG boosted the link between prepregnancy body mass index (ppBMI) and BMI z score, especially in female infants. Females exposed to both maternal obesity with RWG had an average BMI at the 94th percentile (1.50 increase in childhood BMI z score) “nearly at the cutoff for classification of obesity,” compared with those exposed to normal ppBMI with no RWG, who had an average childhood BMI at the 51st percentile.
“Currently, our nutrition recommendations as pediatricians are that all children are fed the same, essentially, after they’re born. We don’t have different growth parameters or different trajectories or targets for children who may have had different in utero exposures,” Dr. Gilley said.
Do some children need more monitoring for RWG?
Though we can’t necessarily draw conclusions from this one study, she says, the findings raise the question of whether children who were exposed in utero to obesity should be monitored for RWG more closely.
Lydia Shook, MD, Mass General Brigham maternal-fetal specialist and codirector of the Diabetes in Pregnancy Program at Massachusetts General Hospital in Boston, said she was struck by the finding in this study that with female infants, but not males, RWG significantly modified the association between ppBMI and early childhood BMI z scores.
“It’s an interesting finding and should be followed up with larger cohorts,” she said, noting that some previous studies have shown males are more vulnerable to maternal obesity and RWG.
“[Often] when we stratify by sex, you really need larger groups to be able to see the differences well,” Dr. Shook said.
She said she also found it interesting that when the researchers adjusted for breastfeeding status or caloric intake in childhood, the findings did not substantially change.
“That’s something that would warrant further investigation in an observational study or controlled trial,” Dr. Shook said.
Preventing rapid weight gain
The authors note that they did not consider possible interventions for preventing RGW in the study, although there are many, Dr. Gilley said.
Dr. Gilley also noted that a limitation of this study is that the population studied was primarily White.
Recent studies have shown the benefits of responsive parenting (RP) interventions, including a large study in 2022 geared toward Black families to teach better infant sleep practices as a way to prevent rapid weight gain.
That study, which tested the SAAF intervention, (Strong African American Families) found that “RP infants were nearly half as likely to experience upward crossing of two major weight-for-age percentile lines (14.1%), compared with control infants (24.2%); P = .09; odds ratio, 0.52; 95% confidence interval, 0.24-1.12.”
Along with sleep interventions, Dr. Gilley said, some researchers are studying the effects on RWG of better paternal engagement, or more involvement with the Women, Infants, and Children program, particularly with lower-income families.
Other studies have looked at breastfeeding vs. formula feeding – “but there have been mixed results there” – and responsive feeding practices, such as teaching families to recognize when a baby is full.
Dr. Gilley said she hopes this work will help broaden the thinking when it comes to infant weight gain.
“We spend a lot of time thinking about babies who are not growing fast enough and very little time thinking about babies who are growing too fast,” she said, “especially in those first 4-6 months of life.”
Dr. Gilley points to a study that illustrates that point. Pesch et al. concluded in a 2021 study based on interviews that pediatricians “are uncertain about the concept, definition, management, and long-term risks of rapid infant weight gain.”
Authors and Dr. Gilley declare no relevant financial relationships.