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Most doctors advise pregnant women to limit the amount of coffee and caffeinated beverages they drink. Our understanding of the way that caffeine affects pregnancy and the development of the baby — both before and after birth — is expanding dramatically.
Here’s what the latest research says about drinking coffee during pregnancy, and why earlier research may have been mistaken.
Coffee contains caffeine, which crosses the placenta. Doctors worry because that means if you drink coffee when you’re pregnant, your baby gets a dose of caffeine. They’re not sure about the effects of caffeine on the development of the brain and other organs. From the 1980s through the early years of this century, research suggested that caffeine during pregnancy might cause miscarriage, premature labor and developmental problems for the baby. Starting around 2004, researchers started taking a closer look at earlier studies and concluded that nearly all of them had significant flaws in the way they collected data, the size of the study or the way they correlated the data. For example, many of the earlier studies didn’t take into account whether or not the mother smoked tobacco during pregnancy. We know that many of the women who drink coffee also smoke, and cigarette smoking has definitely been correlated with miscarriage, low birth weight and premature births. Here’s a look at what the latest research says about drinking coffee and the effects of caffeine on the developing fetus and your pregnancy.
The answer: Older research suggested a connection between caffeine consumption during pregnancy and increased risk of miscarriage, fetal abnormalities and behavioral problems in children after birth. Most research since 2000 has found no evidence that consuming 300 mg of caffeine a day increases the risks of miscarriage or harms the developing fetus. However, most doctors advise that pregnant women consume no more than 300 mg of caffeine daily.
Since the 1980s, doctors have advised pregnant women to abstain from drinking coffee because it might cause miscarriage. A 2004 review of 15 studies found that all of them had significant flaws. However, since that time, several studies have suggested that mothers who consume more than 200 mg of caffeine daily had a higher risk of miscarriage during the early months. Other studies have shown little connection between coffee consumption of less than 300 mg daily and miscarriage.
Source: Maternal caffeine consumption during pregnancy and the risk of miscarriage: a prospective cohort study http://www.ncbi.nlm.nih.gov/pubmed/18221932
Does caffeine cause premature births?
The most recent studies — some as recent as 2013 — contest the long-held belief that caffeine might cause preterm labor and birth. In fact, a number of studies conducted throughout the world have found that maternal consumption of caffeine during the second half of pregnancy has no effect on the length of the pregnancy.
Does caffeine cause low birth weights?
The jury is out on whether maternal caffeine intake affects the birth weight of their babies. Some studies suggest that there is a very small but statistically significant difference in the weight of babies born to mothers who consume coffee, as opposed to caffeine in other forms. However, scientists expect effects to be “dose-dependent” — that is, the more of a substance you consume, the stronger the correlation should be. Most of these studies found that the differences in birth weight were not dose-dependent. Additionally, a 2013 study in Denmark found that there was no difference in length of pregnancy or birth weight between women who drank three cups of caffeinated coffee daily and women who drank three cups of decaffeinated coffee daily during the second half of their pregnancy. They concluded that reducing caffeine intake in the second half of pregnancy does not affect the birth weight of the baby.
Source: Effect of reducing caffeine intake on birth weight and length of gestation: randomised controlled trial http://www.ncbi.nlm.nih.gov/pubmed/17259189
Can my baby be born addicted to caffeine?
The short answer appears to be yes. In 1988, a group of doctors published an article about 8 newborns who appeared to go through caffeine withdrawal immediately after birth. All of their mothers were heavy users of caffeine, and most of the infants had caffeine either in their blood or in their urine. Doctors know that caffeine crosses the placenta, so when you drink coffee, your baby also gets a dose of caffeine. Doctors also know that babies have limited ability to metabolize caffeine before 6 months of age. Since then, there have been a number of other reports in medical journals of babies going through what appear to be caffeine withdrawal symptoms shortly after birth. The good news is that none of them seem to have suffered long-term effects, and all of them resolved without medical intervention.
Does caffeine cause birth defects?
The 2011 National Birth Defects Prevention Study found small but statistically significant risk for total caffeine intake and specific types of caffeinated beverages — but not coffee specifically — for several birth defects. They did not, however, find the dose-response patterns expected, and concluded that there is no convince evidence of an association between maternal caffeine intake and the birth defects included. Likewise, another study found a small but statistically significant increase of limb abnormalities in babies born to mothers who consume caffeine, but again, no dose-response patterns that would suggest caffeine causes those abnormalities.
Perhaps the most concerning reports to date come from a 2012 study published in the Clinical Experiments in Reproductive Medicine. Scientists fed caffeine to lab rats in their drinking water, and followed the offspring from birth through adulthood. They found that high maternal caffeine seemed to impair reproductive development of male rats. An earlier study (2011, Journal of Reproductive Infertility) found that high caffeine consumption during pregnancy and lactation significantly affects the ovarian development of female offspring in rats.
How much caffeine is safe during pregnancy?
The American College of Obstetricians and Gynecologists changed their guidelines regarding caffeine in 2010, stating that moderate caffeine consumption — about 200 mg daily — is safe during pregnancy. European and Australian medical authorities have issued similar guidelines. It’s important to remember, however, that caffeine is found in many different foods, beverages and medicines, not just in coffee.
How much coffee can I drink when I’m pregnant?
Despite the new guidelines, many doctors still suggest that you switch to decaffeinated coffee during pregnancy to be on the safe side. If you must drink caffeinated coffee, you should limit your intake to about 200 mg of caffeine a day. Check out this chart Caffeine in Coffee Drinks and Other Sources and this one how much coffee is too much for more information on the amount of caffeine you might be consuming daily.