Moderate Caffeine Intake During Pregnancy May Lower Gestational Diabetes Risk

During pregnancy, insulin resistance increases and caffeine metabolism decreases, affecting maternal cardiometabolic health and conditions like gestational diabetes.

In the United States, over 80% of women of reproductive age consume coffee daily. Even though most women decrease their caffeine consumption after becoming pregnant, many continue to consume caffeine throughout pregnancy. According to the American College of Obstetricians and Gynecologists (ACOG), pregnant women should limit their caffeine consumption to less than 200 mg/d out of caution because of potential associations with pregnancy loss and fetal growth restriction at higher intakes. The data on associations with maternal cardiometabolic outcomes in pregnancy remains limited.

Outside of pregnancy, caffeine intake is associated with both acute and chronic cardiometabolic changes. For those who are nonhabitual consumers, caffeine intake acutely raises blood pressure. However, among the habitual caffeine consumers, the consumption was associated with lower hypertension risk in prospective cohort studies. Although the long-term effects are limited, experimental studies demonstrated that acute caffeine intake reduces insulin sensitivity. Furthermore, an inverse association between habitual coffee intake and type 2 diabetes was observed through observational studies. Because insulin resistance increases and caffeine metabolism decreases during pregnancy, there was a need to study caffeine with maternal cardiometabolic health.

Previous studies on caffeine (or coffee) and gestational diabetes mellitus, hypertension, and preeclampsia were null except for an inverse association between moderate intakes and preeclampsia. To reduce confounding, a lack of multiple assessments across pregnancy, objective measures, and limited lifestyle measures limited these studies.

Stefanie N. Hinkle and her colleagues conducted a cohort study aiming to examine prospective associations between caffeine exposure in early- and mid-pregnancy and maternal cardiometabolic health, including gestational diabetes mellitus, preeclampsia, and gestational hypertension, as well as cardiometabolic biomarkers and blood pressure. The study revealed that moderate coffee intake in the second trimester was associated with a lower risk for gestational diabetes mellitus (GDM), lower glucose levels at GDM screening, and a more favorable cardiometabolic profile compared with no consumption. However, another intake of caffeine was not associated with gestational hypertension or preeclampsia.

The study’s goal was to determine whether the intake of beverages containing caffeine, plasma caffeine, and paraxanthine are associated with cardiometabolic complications in pregnancy, such as gestational diabetes, preeclampsia, and gestational hypertension. The data included in the study came from a longitudinal pregnancy cohort study from the National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons (2009-2013). The secondary analysis of 2,802 pregnant women without primary chronic conditions enrolled at 12 United States clinical sites was completed in 2021. The final caffeinated beverage analyses included 2,583 women, and 2,529 women in the analyses for plasma caffeine consumption. In addition, the analyses included 319 women for caffeine consumption and fasting cardiometabolic profiles.

The study results showed that at 10 to 13 weeks, 1,073 women reported consuming no caffeine, 1,317 reported consuming one mg/d to 100 mg/d, 173 reported consuming 101 mg/d to 200 mg/d, and 20 reported a consumption higher than 200 mg/d. At 16 to 22 weeks, caffeine intake was associated with lower GDM risk, lower glucose concentrations, lower C-reactive protein, lower C-peptide concentrations, and favorable lipid profiles. In addition, the total plasma caffeine and paraxanthine at 10 to 13 weeks were inversely associated with glucose. There were no associations observed with preeclampsia or gestational hypertension.

Hinkle and her co-researchers concluded that “In this cohort study, second trimester caffeinated beverage intake within current recommendations was associated with lower gestational diabetes mellitus risk, but not preeclampsia or gestational hypertension.”

Practice Pearls:

• Over 80% of adult women in the United States consume caffeine daily.
• The ACOG states that pregnant women should limit their caffeine consumption to less than 200 mg/d.
• The study conducted by Hinkle and colleagues revealed that moderate caffeine intake in the second trimester was associated with a lower risk for gestational diabetes mellitus.

Hinkle, S, et al. Assessment of Caffeine Consumption and Maternal Cardiometabolic Pregnancy Complications. JAMA Network. Retrieved November 20, 2021, from https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2785784#:~:text=Findings%20In%20this%20cohort%20study,cardiometabolic%20profile%20compared%20with%20no

Kevin Suarez, PharmD. Candidate, Creighton University, School of Pharmacy and Health Professions