Exposure to moderate to high caffeine levels while in the womb is potentially associated with an increased risk of excess infant growth and weight gain in early childhood, suggests a large observational study published in the online journal BMJ Open.
Researchers drew data from just under 51,000 mother and infant pairs participating in the Norwegian study between 2002 and 2008. At 22 weeks of pregnancy, the mums-to-be were asked to quantify their food and drink intake from among 255 items, including caffeine.
This study supports current advice to limit caffeine intake to no more than 200mg a day when pregnant. A cup of tea has around 50mg caffeine and an espresso shot around 110mg.
BMJ, April 2018