Featured Research

from universities, journals, and other organizations

Caffeine is linked to miscarriage risk, new study shows

Date:
January 22, 2008
Source:
Kaiser Permanente Division of Research
Summary:
A new study offers the strongest evidence to date linking caffeine consumption during pregnancy to miscarriage because it's the first study to thoroughly control for pregnancy-related caffeine aversion. The study of 1,063 pregnant women found that women who consumed 200 mg or more of caffeine per day doubled their miscarriage risk.

High doses of daily caffeine during pregnancy -- whether from coffee, tea, caffeinated soda or hot chocolate -- cause an increased risk of miscarriage, according a new study by the Kaiser Permanente Division of Research. The study controlled, for the first time, pregnancy-related symptoms of nausea, vomiting and caffeine aversion that tended to interfere with the determination of caffeine's true effect on miscarriage risk.

While previous research showed a link between caffeine consumption and miscarriage, this is the first study to thoroughly control for morning sickness, which typically causes many women to avoid caffeine, explained De-Kun Li, MD, Ph.D., an investigator with the Kaiser Permanente Division of Research and lead investigator of the study. "This study strengthens the association between caffeine and miscarriage risk because it removes speculation that the association was due to reduced caffeine intake by healthy pregnant women," Li said.

To address that speculation, the study, which looked at 1,063 pregnant Kaiser Permanente members in San Francisco from October 1996 through October 1998, examined the caffeine effect among women who never changed their pattern of caffeine consumption during their pregnancy.

Women who consumed 200 mg or more of caffeine per day (two or more cups of regular coffee or five 12-ounce cans of caffeinated soda) had twice the miscarriage risk as women who consumed no caffeine, said Li. Women who consumed less than 200 mg of caffeine daily had more than 40 percent increased risk of miscarriage.

The increased risk of miscarriage appeared to be due to the caffeine itself, rather than other possible chemicals in coffee because caffeine intake from non-coffee sources such as caffeinated soda, tea and hot chocolate showed a similar increased risk of miscarriage.

"The main message for pregnant women from these findings is that they probably should consider stopping caffeine consumption during pregnancy because this research provides clearer and stronger evidence that high doses of caffeine intake during pregnancy can increase the risk of miscarriage," said Li.

The reasons that caffeine can harm a fetus have been suspected for some time. Caffeine crosses through the placenta to the fetus, but can be difficult for the fetus to metabolize because of the under-developed metabolic system. Caffeine also may influence cell development and decrease placental blood flow, which may lead to an adverse effect on fetal development.

Women in the study were asked about their intake of caffeinated beverages as well as the type of their drinks, timing of initial drink, the frequency and amount of intake, and whether they changed consumption patterns since becoming pregnant. Sources of caffeine included coffee, tea, caffeinated soda and hot chocolate.

Researchers estimated the amount of caffeine intake in various types of beverages using the following conversion: For every 150 milliliters of beverage, 100 milligrams for caffeinated coffee, 2 milligrams for decaffeinated coffee, 39 milligrams for caffeinated tea, 15 milligrams for caffeinated soda, and 2 milligrams for hot chocolate. Information on other potential risk factors for miscarriage -- including maternal age, race, education, household income marital status, smoking, alcohol consumption, hot tub use, exposure to magnetic fields during pregnancy, and symptoms related to pregnancy such as nausea and vomited -- also were collected during the in-person interview and controlled during analyses. Pregnancy outcomes up to 20 weeks of gestation were determined for all participants.

Overall, 172 of women in the study (16.18 percent) miscarried. Whereas 264 women (25 percent) reported no consumption of any caffeine containing beverages during pregnancy, 635 women (60 percent) reported 0-200 mg of caffeine intake per day, and 164 women (15 percent) had 200 mg or more of daily caffeine consumption.

Critics had maintained that the association was not so much a high dose of caffeine intake that increased the risk of miscarriage, but that women with a healthy pregnancy are more likely (than those about to miscarry), to reduce their caffeine intake due to nausea, vomiting, and aversion to caffeine," Li said. "Therefore, the critics claimed that the observed association was a result of reduction of caffeine intake by healthy pregnant women."

So what's a fatigued mom-to-be supposed to do for her daily energy jolt?

"If you definitely need caffeine to get you going, try keeping it to one cup or less a day. Avoiding it may be even better. Consider switching to decaffeinated coffee and other decaffeinated beverages during your pregnancy," said Tracy Flanagan, MD, Director of Women's Health, Kaiser Permanente Northern California. "Learn to perk up instead with natural energy boosts like a brisk walk, yoga stretches, snacking on dried fruits and nuts."

The research appears in the current online issue of American Journal of Obstetrics and Gynecology.

Co-authors on the study included Xiaoping Weng, Ph.D. and Roxana Odouli, MSPH, also with the Kaiser Permanente Division of Research. The Study was supported in part by the California Public Health Foundation.


Story Source:

The above story is based on materials provided by Kaiser Permanente Division of Research. Note: Materials may be edited for content and length.


Journal Reference:

  1. Xiaoping Weng, Roxana Odouli, De-Kun Li. Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study. American Journal of Obstetrics & Gynecology, 2008; 198 (3): 279.e1-279.e8 DOI: 10.1016/j.ajog.2007.10.803

Cite This Page:

Kaiser Permanente Division of Research. "Caffeine is linked to miscarriage risk, new study shows." ScienceDaily. ScienceDaily, 22 January 2008. <www.sciencedaily.com/releases/2008/01/080121080402.htm>.
Kaiser Permanente Division of Research. (2008, January 22). Caffeine is linked to miscarriage risk, new study shows. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2008/01/080121080402.htm
Kaiser Permanente Division of Research. "Caffeine is linked to miscarriage risk, new study shows." ScienceDaily. www.sciencedaily.com/releases/2008/01/080121080402.htm (accessed April 23, 2014).

Share This



More Health & Medicine News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Big Pharma Braces for M&A Wave

Big Pharma Braces for M&A Wave

Reuters - Business Video Online (Apr. 22, 2014) Big pharma on the move as Novartis boss, Joe Jimenez, tells Reuters about plans to transform his company via an asset exchange with GSK, and Astra Zeneca shares surge on speculation that Pfizer is looking for a takeover. Joanna Partridge reports. Video provided by Reuters
Powered by NewsLook.com
Study Says Most Crime Not Linked To Mental Illness

Study Says Most Crime Not Linked To Mental Illness

Newsy (Apr. 22, 2014) A new study finds most crimes committed by people with mental illness are not caused by symptoms of their illness or disorder. Video provided by Newsy
Powered by NewsLook.com
Hagel Gets Preview of New High-Tech Projects

Hagel Gets Preview of New High-Tech Projects

AP (Apr. 22, 2014) Defense Secretary Chuck Hagel is given hands-on demonstrations Tuesday of some of the newest research from DARPA _ the military's Defense Advanced Research Projects Agency program. (April 22) Video provided by AP
Powered by NewsLook.com
How Smaller Plates And Cutlery Could Make You Feel Fuller

How Smaller Plates And Cutlery Could Make You Feel Fuller

Newsy (Apr. 22, 2014) NBC's "Today" conducted an experiment to see if changing the size of plates and utensils affects the amount individuals eat. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins