Caffeine is a stimulant in coffee, tea, chocolate and some soft drinks, and it’s an integral part of nearly every culture. Caffeine and fertility aren’t a great mix as the ‘pick-me-up’ or energy boost is stimulating in a similar way to drugs like cocaine, but on a lower level! With a regular intake, people can develop dependence as they “need” to reach a normal level of stimulation, or they feel flat and lethargic without it.
Tea, chocolate and coffee have many health benefits, so they’re definitely not “bad”, but caffeine has some unwanted effects as far as fertility is concerned. Most information on caffeine and fertility is from studies using coffee, and there’s little data on how sources of caffeine vary effects. However, tea and coffee have different properties and affect the body in very different ways.
The American Congress of Obstetricians and Gynaecologists i advises up to 200 mg of caffeine a day is safe for pregnant women. There’s always debate around research, and it’s known coffee can significantly:
- Reduce the chances of getting pregnant
- Increase the risk of miscarriage
- Increase the risk of “stillbirth”
Likelihood of pregnancy
- Women are twice as likely to get pregnant each cycle when they drink less than one cup of coffee a day compared to moderate coffee drinkers
- Increasing coffee intake reduces a women’s chance of conceiving ii
- Having over 500 mg of caffeine a day makes it take (on average) over 9½ months longer to get pregnant iii
Risk of miscarriage
- Between 150 and 300 mg of caffeine, a day is linked to a three-fold increase in miscarriage risk
- Over 300 mg of caffeine, a day is linked to a sixteen-fold increase in the risk of miscarriage iv
- Genetic abnormalities cause most miscarriages but are less common when women who over 500 mg of caffeine a day, suggesting high caffeine intake encourages a higher proportion of “healthy foetus” miscarriages v
- Women who have over 375 mg of caffeine a day are over twice as likely to have spontaneous miscarriages as women who have less than 200 mg of caffeine a day vi
Risk of still-birth
- Women drinking 4-7 cups of coffee a day during pregnancy have a nearly 80% increased chance of still-birth
- Women who drink over 8 cups of coffee a day have nearly a 300% increased chance of still-birth vii
The amount of caffeine in foods and drinks varies, but a general guide to caffeine content is: viii
|Milk chocolate bar||9|
|Dark chocolate bar||20|
|Anacin (2 tabs)||64|
|Starbucks Hot Chocolate||25|
|McDonald’s coffee (16oz)||133|
|Maxwell House Ground Coffee (12oz)||100-160|
|Starbucks Espresso (2oz)||150|
|Starbucks Venti coffee (20 oz)||415|
|Zantrex-3 weight loss supplement (2 caps)||300|
|Monster Energy Drink (16oz)||160|
|Bang Energy Drink (16oz)||357|
Tea and coffee
Foods and drinks vary in terms of their temperature (mint or ginger), energetic properties and actions. Although all the substances above contain caffeine, coffee affects us differently from tea or chocolate. The nature of coffee is very warming and stimulating (which is fine in small amounts), but too much stimulation both hides and encourages exhaustion. When this goes on for a long time, it can cause an imbalance in the body, and like alcohol, coffee has a greater impact as we age.
- Affects the heart and can cause insomnia, jitteriness and palpitations
- The Heart controls the blood and circulation in eastern medicine traditions, and coffee “enters” and affects the function of an important channel that passes through the womb and regulates the cycle x
The overall effect of coffee increases a sense of agitation and encourages “heat in the blood” which increases the chances of abnormal bleeding compared to tea or chocolate. The US National Institutes of Health’s view is:
“[Too] much caffeine can make you restless, anxious, and irritable. It may also keep you from sleeping well and cause headaches, abnormal heart rhythms, or other problems. Some people are more sensitive to the effects of caffeine than others. They should limit their use of caffeine. So should pregnant and nursing women” xi
Tea is quite different to coffee as it’s cooling, and while it’s a diuretic, it doesn’t directly affect the heart or the blood and is generally seen as calming.
iiWilcox, A., Weinberg, C. et al. (1988). ‘Caffeinated beverages and decreased fertility.’ Lancet 2(8626-8627): 1453-1456.
iiiBolúmar F, Olsen J, Rebagliato M, Bisanti L: European Study Group on Infertility and Subfecundity. ‘Caffeine intake and delayed conception: A european multicenter study on infertility and subfecundity’. Am J Epidemiol 1997, 145:324–334.
iv Stefanidou EM, Caramellino L, Patriarca A, Menato G: ‘Maternal caffeine consumption and sine causa recurrent miscarriage’. Eur J Obstet Gynecol Reprod Biol 2011, 158:220–224.
vCnattingius S, Signorello LB, et al: Caffeine intake and the risk of first-trimester spontaneous abortion. N Engl J Med 2000, 343:1839–1845.
viRasch V: ‘Cigarette, alcohol, and caffeine consumption: Risk factors for spontaneous abortion.’ Acta Obstet Gynecol Scand 2003, 82:182–188.
viiWisborg K, Kesmodel U, Bech BH, Hedegaard M, Henriksen TB: Maternal consumption of coffee during pregnancy and stillbirth and infant death in first year of life: Prospective study. BMJ 2003, 326:420.
viii Adapted from http://www.cspinet.org/new/cafchart.htm
ix‘ Clinical handbook of Internal Medicine. Vol.1’ Maclean and Lyttleton, 1998, University of Western Sydney Press
x ‘Helping ourselves: A guide to traditional Chinese food energetics’. Daverick Leggett, 1994, Meridian Press
xi“Caffeine”. MedlinePlus: U.S. National Library of Medicine. Retrieved 27 October 2012.