Study shows bad mix between caffeine and pregnancy

Published 12:00 am Friday, January 25, 2008

Pregnant? Like coffee?

A new study released Monday on the American Journal of Obstetrics’ website has found that too much caffeine consumption during pregnancy increases the risk of miscarriage by twofold.

The Kaiser Permanente Division of Research, located in California, performed the study on over 1,000 pregnant women and monitored their caffeine consumption during pregnancy.

It found that for women who consumed more than 200 mg of caffeine a day (about 10 ounces of regular coffee – barely more than a small cup), they were twice as likely to miscarry compared to women who consumed no caffeine.

Even women who consumed some caffeine – but less than 200 mg – miscarried at a rate 40 percent higher than those who abstained completely.

However, that number wasn’t considered statistically significant.

Doctors and scientists have long since suspected that caffeine was potentially harmful during pregnancy, but conflicting studies and unclear results have cast doubt over the years.

Nevertheless, most doctors have for decades recommended that a pregnant woman at least cut back her caffeine consumption during pregnancy to no more than a few cups of coffee a day.

Now, the recommended amount will likely be cut almost in half.

The Roanoke-Chowan News-Herald spoke with an area obstetrician/gynecologist and a certified nurse midwife regarding the newest study.

Dr. Robert Cooke and Lynn Miles, both operating out of Women’s Care in Ahoskie, care for many of the area’s pregnant women.

Cooke says his recommendation to patients will not change by much.

&uot;I’ve always told women to limit caffeine to one serving a day, which is eight ounces (one cup) of coffee,&uot; he said.

He continued, &uot;There have been lots of studies in the past regarding caffeine; the problem is none were well-controlled, but all along we’ve suspected problems with caffeine.&uot;

The American College of Obstetricians and Gynecologists and the March of Dimes have both historically recommended that women limit caffeine to one or two cups of coffee a day.

However, the March of Dimes has already announced that it will soon begin recommending women to cut caffeine out of their diet completely – which includes coffee, tea, soft drinks and chocolate.

Though the new study claimed better controls than previous studies on caffeine, Cooke warns that it was still not perfectly controlled and as such the results might not be entirely accurate.

&uot;There are still problems with this new study. It didn’t study the causes of miscarriage like genetic abnormalities,&uot; he noted.

To do that and study the tissue of each miscarried fetus would have been very expensive, Cooke said.

&uot;However,&uot; he continued, &uot;there have been a lot of studies done on this and none of them had good results, therefore it is still best to reduce caffeine intake during pregnancy.&uot;

Caffeine is known to have the ability to cross through the placenta to the fetus and it may also be difficult for the fetus to process because of its under-developed metabolic system.

It is also thought to decrease placental blood flow, which may cause problems with fetal development.

The average eight-ounce cup of coffee contains 120 mg of caffeine. A glass of iced tea (eight ounces) has about 50, depending on the brew strength.

Caffeinated soft drinks average 35 mg per eight-ounce serving, but can go as high as 55, so a 20-ounce bottle would contain 87.5 mg, or up to 137.5 mg.

A Hershey’s chocolate bar has about 10 mg of caffeine.

For more information on caffeine and pregnancy, discuss your concerns with your doctor at your next prenatal visit.