Researchers from the Nationwide Children’s Hospital looked at data collected in America between 1959 and 1974, which measured the caffeine intake of 2,200 women during their pregnancies.
The children born had IQ and behavioural assessments when they were four and seven years old.
The researchers found there was no evidence that a mother's caffeine consumption had any effect on the children.
Drinking a "moderate" amount of caffeine is unlikely to impact children, researchers suggest
The results of the study were published on 18 November in the American Journal of Epidemiology.
Dr. Mark Klebanoff, study author, said: "These results provide at least some reassurance that caffeine, at the amounts that most people would be drinking, is not likely to have an important impact on the development of their children."
During the study, the research team studied blood samples from the women. Caffeine levels were checked during two points in the pregnancy, which were then compared to the resulting child's IQ levels and behaviour.
The samples were initially acquired to screen the mothers for infections while pregnant, but were archived for future research, such as this study.
Dr. Mark Klebanoff added: "Taken as a whole, we consider our results to be reassuring for pregnant women who consume moderate amounts of caffeine or the equivalent to one or two cups of coffee per day."
The NHS suggests women should limit the amount of caffeine they consume during pregnancy.
They advise: "You don’t need to cut caffeine out completely, but you should limit how much you have to no more than 200mg a day.
"High levels of caffeine during pregnancy can result in babies having a low birth weight, which can increase the risk of health problems in later life. Too much caffeine can also cause a miscarriage."
Dr Clare Thompson said the UK does not have clear guidelines about caffeine consumption in pregnancy.
She told HuffPost UK Parents: "The UK NICE guidance suggests that 300 mg of caffeine per day is the upper limit of what would be acceptable for a pregnant woman to consume on a daily basis, although there is no clear and confounding data to support or refute these claims.
"The RCOG had recommended that pregnant women should aim to eliminate caffeine altogether in the first trimester, after which women are advised not to consume more than 200mg of caffeine per day.
"Sensible advice would be to restrict maternal consumption to 200 mg per day or less before conception and throughout pregnancy."
Experts have warned that caffeine's overall impact on foetal growth and development is still largely undetermined, according to Tech Times.