Moderate Caffeine Intake in Pregnancy Tied to Reduced Cardiometabolic Risk

By Lisa Rapaport

November 09, 2021

(Reuters Health) - Pregnant women with low to moderate caffeine consumption may have a lower risk of gestational diabetes, lower glucose levels and a better cardiometabolic risk profile than their counterparts who avoid caffeine entirely, a new study suggests.

Researchers examined data on 2,802 pregnant women without any major comorbidities who were part of the National Institute of Child Health and Human Development Fetal Growth Studies-Singletons from 2009 to 2013. Daily total caffeine intake at 10 to 13 weeks and at 16 to 22 weeks of pregnancy was calculated based on self-reported consumption of coffee, tea, soda and energy drinks; women also provided blood samples to measure caffeine and paraxanthine at 10 to 13 weeks gestation.

Earlier in pregnancy, at 10 to 13 weeks gestation, there were 1,073 women (41.5%) who reported no caffeine consumption. A total of 1,317 women (51.0%) reported intake of 1mg to 100mg daily, while 173 women (6.7%) said they consumed 101mg to 200 mg per day, the maximum amount recommended during pregnancy. Another 20 women (0.8%) had more than 200mg daily.

Later in pregnancy, at 16 to 22 weeks gestation, there were 599 women (23.6%) who said they didn't consume any caffeinated beverages; 1734 (68.3%) who said they had 1 mg/d to 100 mg/d, 186 (7.3%) who said their intake was 101 mg/d to 200 mg/d; and 20 (0.8%) reported consuming more than 200 mg/d caffeinated beverages.

Low caffeine consumption of 1mg to 100mg daily was associated with a lower risk of gestational diabetes earlier in pregnancy (relative risk 0.71) and later in pregnancy (RR 0.53).

Moderate caffeine consumption of 101mg to 200mg daily was also associated with a lower risk of gestational diabetes later in pregnancy (RR 0.54). Higher caffeine consumption, however, was associated with an increased risk of gestational diabetes earlier in pregnancy (RR 1.87).

The results, published in JAMA Network Open, are in line with the current guidelines from the American College of Obstetricians and Gynecologists (ACOG) that pregnant women limit their caffeine consumption to less than 200 mg per day, said lead study author Stefanie Hinkle, an assistant professor in the Department of Biostatistics, Epidemiology and Informatics at the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.

"These findings are consistent with studies that have found that caffeine in itself has been associated with improved energy balance and decreased fat mass, which may explain the observed findings," Hinkle said by email.

However, it's possible that the results might have been influenced by other components of coffee and tea such as phytochemicals that may impact inflammation and insulin resistance, leading to a lower risk for gestational diabetes, Hinkle said.

"Additional research is needed to fully understand the mechanisms of the findings observed in this study," Hinkle said.

One limitation of the study is that it was too small to assess any differences in outcomes based on what type of caffeinated beverage women consumed or how it was prepared. Researchers also lacked data on the exact timing of any gestational diabetes diagnoses.

While clinicians and patients should be reassured by the study results that current guidelines around pregnancy and caffeine are sensible, the results shouldn't encourage women to start drinking caffeinated beverages for the first time during pregnancy, Hinkle said.

"It would not be prudent for women who are non-drinkers to initiate caffeinated beverage consumption for the purpose of lowering GDM risk and improving glucose metabolism," Hinkle said. "However, these findings may provide some reassurance to women who already are consuming low to moderate levels of caffeine that such consumption likely will not increase their risk for gestational diabetes."

SOURCE: JAMA Network Open, online November 8, 2021.