Certain Gestational Weight Gain Patterns Linked to More Growth in Female Offspring

Dramatic gestational weight gain led to unique growth patterns in female offspring at ages 5 to 14 years, an observational study suggested.

Of four pregnancy weight gain patterns identified among 337 mother-child pairs, the one that had the greatest effect on offspring growth was one in which mothers rapidly gained weight during the first 10 weeks of pregnancy, then plateaued with slower weight gain, and then resumed moderate weight gain for the last few weeks of pregnancy, reported Elizabeth M. Widen, PhD, RD, of the University of Texas at Austin, and colleagues in the journal Obesity.

Girls born to mothers who followed this pregnancy weight gain pattern tended to have the highest BMI z scores, waist circumferences, and body fat percentages from ages 5 to 14. Of note, boys exposed to this weight pattern in utero didn’t follow this heightened growth pattern.

“We wanted to understand whether different weight change patterns during pregnancy impacted the child’s growth over time or the child’s potential to develop excess fat tissue,” Widen explained in a statement. “For boys, we didn’t really see that much of a difference in their patterns of weight and body size over time. But for girls, we saw some striking differences. This tells us there are differences between the sexes in this area of child growth.”

Children exposed to the virtually opposite pregnancy weight pattern — mothers who lost weight during the first 10 weeks of pregnancy, then moderately gained in the second trimester, capped with a rapid weight gain at weeks 30 through 40 — tended to have the lowest BMI z scores, waist circumferences, and body fat percentages.

“This study shows us that there may be sex differences in child body composition based on what they are exposed to in utero,” Widen added. “But, really, we believe there is only a small portion of pregnancy weight gain that can be consciously changed — specifically among fat tissue — since much of the weight change is necessary to support the pregnancy.”

“It is possible that these findings are just the start of research that can help us further understand risk factors for childhood obesity and may help us develop more individualized weight gain guidelines that support pregnant people,” she said.

Widen’s group drew upon data from the Columbia Center for Children’s Environmental Health Mothers and Newborns Study. Dominican and Black mothers ages 18 to 35 who did not have diabetes at baseline were included. Gestational weight gain patterns were obtained through medical records, and offspring growth patterns were collected regularly at a maximum of seven follow-up visits.

The four categories of pregnancy weight gain trajectories with their corresponding average weekly weight gains during each of the three trimesters were:

• Rapid, slow, moderate: 1.92 lb/week, 0.62 lb/week, 1.03 lb/week
• Loss, moderate, rapid: -0.37, 1.02, 1.91
• Always slow: 0.63, 0.87, 0.72
• Slow, moderate, moderate: 0.27, 1.17, 1.37

By far the most common trajectory that women followed was the “slow, moderate, moderate” trajectory (44.4% of women). The second most popular trajectory was “always slow” (32%), followed by “rapid, slow, moderate” (13.8%), and “loss, moderate, rapid” (9.8%).

Of note, mothers with pre-pregnancy obesity were far more likely to follow the “rapid, slow, moderate” pregnancy weight gain trajectory.

“This mother-child dyad joint model offers a new approach to characterizing how body composition develops over time by allowing postnatal body composition changes to drive groupings of prenatal weight to understand the drivers of growth and adiposity development,” the researchers explained. “We developed this mother-child dyad modeling approach to gain more insight into how prenatal and postnatal body compositions are interrelated.”

Some limitations to the study included a lack of data on lifestyle factors, like prenatal and postnatal diet and exercise, and no data on pubertal timing in offspring.