How much caffeine intake is safe during pregnancy? Answer is not as simple as it seems

Pregnant women and those who are trying to conceive should not consume coffee or other caffeinated products at all to prevent birth defects and other poor outcomes, according to a recent literature review. Some experts, however, disagree and told CNN that 200 milligrams of caffeine per day is safe.

The American College of Obstetricians and Gynaecologists (ACOG) and the National Health Service (NHS) recommend pregnant women to restrict their caffeine intake to 200 milligrams (mg) a day (~ 2 mugs of instant coffee) to avoid risk of miscarriage and health problems in child. However, a new study finds that there is no safe level of maternal caffeine consumption.

Professor James from Reykjavik University conducted a review of studies related to maternal caffeine intake and pregnancy outcomes and found that:

• Maternal caffeine consumption is associated with increased risk for
  • Miscarriage 
    • Risk increases by 7%-14% for each increment of 100 mg caffeine consumed per day during pregnancy and 19% for each 150 mg increment
  • Stillbirth 
    • Increased risk of stillbirth per 100 mg caffeine per day by 9%-19%
  • Low-birth weight and/or small for gestational age 
    • “every additional 100 mg per day of maternal caffeine was associated with an increased risk for LBW of 7% in one of two meta-analyses and 13% in the second.”
  • Childhood acute leukemia
  • Childhood overweight and obesity

• Maternal caffeine consumption was not found to be linked with risk of preterm birth

According to the author, “current advice such as that issued by ACOG, the DGAC,EFSA and the NHS is not consistent with the level of threat indicated by biological plausibility of harm and extensive empirical evidence of actual harm. Accordingly, current health recommendations concerning caffeine consumption during pregnancy are in need of radical revision. Specifically, the cumulative scientific evidence supports pregnant women and women contemplating pregnancy being advised to avoid caffeine.”

Some experts, however, do not support the findings of the research and told CNN that 200 milligrams of caffeine per day is still a safe level. Experts questioned the reliability of results of new review study for several reasons:

• The results are based on self-reported consumption data, which could be inaccurate
• The study was observational and hence we can not establish causal inference
• Experts agree that high caffeine intake by pregnant women is risky but believe “pregnant women do not need to cut caffeine out entirely because these risks are extremely small”

More investigation through randomized controlled trials would help to understand exactly how much caffeine consumption during pregnancy is safe.