A clear links exists between expecting mothers who drink coffee and low birth weight, claims a new study. In addition to underweight births, coffee may also make pregnancy last longer, however, only by a couple of hours.
This new information comes from research studying the detailed records of close to 60,000 pregnancies over a ten year period in Norway. The study included information about how often the expectant mothers had food or beverages containing caffeine. This includes tea, coffee, chocolate sandwich spread and chocolate bars.
Comparing the results of this study with their newborn babies revealed a link between caffeine and birth weight, with 200mg to 300mg of daily caffeine intake increasing the odds for the baby being decidedly small for the length of the gestation by up to 62 percent.
A cup of instant coffee contains about 100mg of caffeine, while a mug of filtered coffee contains around 140mg of caffeine. However, some drinks that are sold in coffee shops locally contain as much as 300mg of caffeine per cup.
Pregnant women are generally advised to limit their caffeine intake to around 200mg each day.
Coffee, specifically, has been linked to increasing the duration of pregnancy. In fact, a daily cup of instant coffee has been found to lengthen the time that the baby stays in the womb up to eight hours. However, unlike some previously conducted studies, the research in this particular study did not make a direct link between caffeine and premature birth rate.
Researcher Dr Verena Sengpiel, of the Sahlgrenska University Hospital in Sweden, says caffeine may negatively affect the growth of unborn babies by slowing down the passage of vital nutrients from the mother to the baby via the placenta.
Writing in the journal BMC Medicine, she added that coffee might increase the length of pregnancy by interfering with the brain’s chemical signals around the onset of labor.
Follo Dr Euan Paul, of the British Coffee Association, said, “The UK Food Standards Agency carefully analyzed and thoroughly reviewed the effects of caffeine during pregnancy and currently recommends that pregnant women moderate consumption to an upper safe limit of 200mg / day - two to three cups of coffee. Switching to decaf during pregnancy is also an option for those who wish to continue drinking coffee.”
Annette Briley, a consultant midwife for the charity Tommy’s, said, “Being born small can lead to catch-up growth and this in turn can lead to obesity, diabetes and certain cancers in adult life. We welcome more research into this important area so that the associations found in this study can be further explored.”
In a study conducted by Glasgow University researchers in 2011, pregnant women were warned that they could unwittingly be putting the health of their unborn baby at risk by drinking coffee from high street cafes. The analysis of espresso from 20 coffee shops in the area found enormous variations between the amounts of caffeine each contained, the strongest having six times as much as the weakest espresso.