More than one cup of coffee or tea per day may be too much for pregnant women according to a new study, which suggests consuming caffeine at any point during pregnancy is linked to low birth weight.
Researchers from the Universities of Leicester and Leeds have confirmed that any amount of caffeine, be it from coffee, pop, chocolate or some types of prescription drugs, is linked with slower fetal growth.
The study found that, compared to women who consumed less than 100 milligrams of caffeine per day, the risk of having a low-birth weight baby increased by:
- 20 per cent for a caffeine intake between 100 and 199 mg/day.
- 50 per cent for a caffeine intake between 200 and 299 mg/day.
- 40 per cent for a caffeine intake over 300 mg/day.
The researchers also found that ingesting more than 100 mg of caffeine per day during the first trimester was linked to a 34 gram to 59 gram reduction in birth weight.
Consuming 100 mg per day during the second trimester corresponded with a 24 gram to 74 gram reduction in birth weight and the same consumption during the third trimester was linked to a 66 gram to 89 gram birth-weight reduction.
A cup of coffee generally contains about 100 mg of caffeine.
"We suggest that sensible advice for women contemplating pregnancy is to reduce their caffeine intake from all sources before conception," the authors concluded. "Once pregnancy is confirmed, they should make every effort to stop or markedly reduce caffeine consumption."
The findings were published Monday on bmj.com.
According to the study, previous research has linked caffeine intake greater than 300 mg/day to low birth weight.
Babies born at a low birth weight are at greater risk for a myriad of health problems, including diabetes, heart disease, compromised immune function and cognitive difficulties.
For their study, the researchers measured the caffeine intake and tested the caffeine metabolism of more than 2,600 women.
The average caffeine intake among the subjects was about 159 mg/day, which is lower than the previous British Food Standards Agency recommended limit of 300 mg/day for pregnant women.
In the wake of the study, the FSA has lowered its recommended limit to 200 mg per day.
The researchers pointed out that scientists do not yet know if the caffeine or one of its by-products is responsible for the increased risk to a fetus.
