Caffeine content in newborn hair correlates with maternal dietary intake

Abstract

Purpose High-maternal caffeine intake during pregnancy may be harmful for perinatal outcomes and future child health, but the level of fetal cumulative exposure has been difficult to measure thus far. Here, we present maternal dietary caffeine intake during the last trimester and its correlation to caffeine content in newborn hair after birth. Methods Maternal third trimester diets and dietary caffeine intake were prospectively collected in Kuopio Birth Cohort (KuBiCo) using a 160-item food frequency questionnaire (n = 2840). Newborn hair was collected within 48 h after birth and analyzed by high-resolution mass spectrometry (HRMS) for caffeine (n = 316). Correlation between dietary caffeine intake and neonatal hair caffeine content was evaluated from 203 mother-child pairs. Results Mean dietary caffeine intake was 167 mg/days (95% CI 162-172 mg/days), of which coffee comprised 81%. Caffeine in the maternal diet and caffeine content in newborn hair correlated significantly (r = 0.50; p < 0.001). Older, multiparous, overweight women, and smokers had the highest caffeine levels in the maternal diet, as well as in their newborn babies' hair. Conclusion Caffeine exposure, estimated from newborn hair samples, reflects maternal third trimester dietary caffeine intake and introduces a new method to assess fetal cumulative caffeine exposure. Further studies to evaluate the effects of caffeine exposure on both perinatal and postnatal outcomes are warranted, since over 40% of pregnant women consume caffeine more than the current suggested recommendations (European Food Safety Association, EFSA recommendations).

Maternal caffeine consumption and pregnancy outcomes: a narrative review with implications for advice to mothers and mothers-to-be

“…Whereas many consume less or none, a sizeable proportion regularly consumes more. 15 In that regard, the dose-response estimates of caffeine-related harm reported by Greenwood et al 57 may be used to gauge the potential population impact assuming a uniform maximum 'safe' level of consumption by all pregnant women. Under those circumstances, the minimum impact, by any reckoning, would be of the order of tens of thousands of avoidable negative pregnancy outcomes per year in the USA alone.…”

“…Whereas many consume less or none, a sizeable proportion regularly consumes more. 15 In that regard, it is instructive to use the Greenwood et al 57 estimates of caffeine-related harm to compute the potential population impact assuming a uniform maximum 'safe' level of consumption by pregnant women. The computational steps are summarised in table 2, which shows that general consumption at the widely endorsed 'safe' limit of 200 mg per day would account for approximately 350 000 negative pregnancy outcomes per year in the USA (about one-quarter of the population total attributable to the four outcomes referred to in the table).…”

“…Notwithstanding the current broad consensus among health authorities, a recent study found that more than 40% of pregnant women in Finland reported consuming more than the widely promulgated recommended maximum of 200 mg caffeine per day. 15 This narrative review was undertaken for the dual purpose of (1) assessing current evidence concerning caffeine-related pregnancy outcomes, and (2) determining whether current health advice concerning maternal caffeine consumption is soundly based.…”

“… 18 19 The extent of diffusion of caffeine from maternal to fetal circulation is indicated by the presence of caffeine in fetal hair, with concentrations in the hair of newborns being found to correlate well with maternal caffeine consumption during the third trimester. 15 In adults, caffeine is metabolised principally by cytochrome P450 enzymes (mono-oxygenase and xanthine oxidase enzymes) in the liver. However, because the P450 enzyme system remains undeveloped until infancy, 20 21 the kidneys are the main route of excretion in newborns with more than 80% of the drug passing unchanged in urine compared with only 2–4% of unchanged caffeine in adults.…”

Drinks and Food Caffeine Consumption and Factors Associated With Higher Intakes. A Cohort Study In Pregnant Women

“…On the contrary, more than 40% of pregnant women in Finland reported consuming more than the recommended maximum of 200 mg of caffeine per day. [29] In this study and in the American one, coffee is the main source of caffeine, assuming over 60% of total consumption [30]. This also happens in Asian pregnant women.…”