Increased caffeine consumption during pregnancy impacts growth of fetus: JAMA

Short height in early cildhood was linked to intrauterine exposure to rising quantities of caffeine and paraxanthine, says an article published in the Journal of American Medical Association.

The relationship between increased coffee intake during pregnancy and smaller babies' birth weights is uncertain, though. In order to assess the relationships between pregnant caffeine and paraxanthine measurements and child development in a current cohort with low caffeine use and a historical cohort with high caffeine consumption, Jessica Gleason and colleagues carried out this study.

The National Institute of Child Health and Human Development's Environmental Influences on Child Health Outcomes Cohort (ECHO-FGS; 10 sites, 2009–2013) was a prenatal cohort with one child measurement between the ages of 4 and 8 years (follow-up in 2017-2019). The Collaborative Perinatal Project (CPP) was an eight-year child follow-up study of a cohort of pregnant women from 12 sites between 1959 and 1965. (1960-1974). In 2021 and 2022, the present secondary analysis was completed. Caffeine concentrations and its main metabolite, paraxanthine, were measured in first-trimester plasma (ECHO-FGS) and serum (CPP) samples. For ECHO-FGS and CPP, quartiles and quintiles served as the cut thresholds for analysis. The primary outcomes included the evaluation of the child's z scores for body mass index, weight, and height, as well as the fat mass index, percentage and obesity risk measured once between the ages of 4 and 8 years in the ECHO-FGS. Child z scores and obesity risk were examined longitudinally until age 8 in a secondary analysis of the CPP cohort.

The key findings of this study were:

1. In the ECHO-FGS (median caffeine consumption 50 mg/d), 788 children (mean [SD] age, 6.8 [1.0] years; 411 boys [52.2%]) of women had lower height z scores, while changes in weight z scores were only seen in the third quartile.

2. 1622 children in the highest caffeine quintile group of mothers in the CPP had lower height z scores than their peers in the lowest group starting at age 4 years old, and the difference grew larger with each passing year of age.

3. At ages 5 to 8 years, children in the third vs. first caffeine quintile had somewhat lower weights.

4. For paraxanthine concentrations in both cohorts, the results were similar.

In conclusion, reductions in height and weight may or may not have clinical implications, but they were still noticeable even when caffeine intake was below the clinically advised threshold of less than 200 mg per day.

Reference:

Gleason, J. L., Sundaram, R., Mitro, S. D., Hinkle, S. N., Gilman, S. E., Zhang, C., Newman, R. B., Hunt, K. J., Skupski, D. W., Grobman, W. A., Kannan, K., & Grantz, K. L. (2022). Association of Maternal Caffeine Consumption During Pregnancy With Child Growth. In JAMA Network Open (Vol. 5, Issue 10, p. e2239609). American Medical Association (AMA). https://doi.org/10.1001/jamanetworkopen.2022.39609