Does coffee cause miscarriage, pre-term birth and other pregnancy issues?

Pregnant? You no longer have to give up your cup of "joe," as confirmed by new research

 Cup of coffee (photo credit: INGIMAGE)
Cup of coffee
(photo credit: INGIMAGE)

A new study has found that coffee consumption during pregnancy does not correlate with miscarriage, stillbirth, birthweight, gestational age and pre-term birth.

Slow-roasted study

Researchers at the University of Queensland in Australia have confirmed that there is no increased risk of pregnancy using the Mendelian Randomization (MR) method. 

“When it comes to diet during pregnancy women are often advised to cut things out, but this study shows they can still enjoy coffee without worrying about increasing the risk of these pregnancy outcomes.”

Dr. Daniel Hwang

Mendelian Randomization is a technique for examining the causal relationship between a changeable exposure and illness in observational studies by employing measured variation in genes with known functions.

“Because we can’t ask women to drink prescribed amounts of coffee during their pregnancy, we used genetic analyses to mimic a randomized control trial,” said Dr. Daniel Hwang.

Researchers used 8 different genetic variants to see if drinking coffee is connected to certain birth outcomes.

The peer-reviewed paper published in the Oxford Academic study used genetic data to verify this evidence.

Researchers Dr. Gunn-Helen Moen, Dr. Daniel Hwang and Caroline Brito Nunes from UQ’s Institute for Molecular Bioscience were unable to confirm if coffee consumption affects any other factors in pregnancy.

As reported in the paper, Pregnancy-induced changes in the pharmacokinetics of caffeine and its metabolites, a female’s caffeine metabolism decreases and the active metabolite concentration increases during pregnancy, especially in the third trimester due to physiological changes. This means that reduced liver enzyme activity is the root cause. For context, 70% of women in the United States consume coffee, using it as their main source of caffeine.

Drink less coffee?

The World Health Organization affirmed that pregnant women should drink less than 300mg of caffeine, proportionate to 2-3 cups of coffee, according to Dr. Gunn-Helen Moen. This is because it is difficult to separate coffee from other components such as drug and alcohol usage, as they are not monitored separately.

“When it comes to diet during pregnancy women are often advised to cut things out, but this study shows they can still enjoy coffee without worrying about increasing the risk of these pregnancy outcomes,” Dr Hwang said.

The institute's department asserted that although it is acceptable for pregnant women to drink caffeine, they should not be encouraged to drink excessive amounts since the institute cannot confirm whether or not caffeine intake can affect other elements of fetal development. The Avon Longitudinal Study of Parents and Children [ALSPAC], used to comprehend how environmental and genetic factors may influence parents' and children's development and health, emphasizes this uncertainty.