Caffeine and pregnancy: what's safe?

Do I have to give up caffeine now that I'm pregnant?

You don't have to give up caffeine, but you may want to cut down.

If you have too much caffeine your baby could have a lower birth weight than he should (CARE 2008). A low birth weight increases the risk of your baby having some health problems when he's born and in the future. There is also a possibility that high levels of caffeine could cause miscarriage (FSA n.d. b). One study suggested that even low levels of caffeine could be linked to miscarriage (Weng et al 2008).

Guidelines issued by the Food Standards Agency recommend that pregnant women have no more than 200mg of caffeine a day (FSA n.d. a). This is equivalent to two mugs of instant coffee or four cups of tea or five cans of cola per day (FSA n.d. a).

What exactly does caffeine do to my body?

Caffeine is a stimulant; it increases your heart rate and metabolism, which in turn affects your developing baby (OTIS 2006). But while unremitting stress isn't healthy, brief bouts of fetal stress, such as that your baby would feel after you drink a cup of coffee, shouldn't cause him any harm. It's akin to your dashing to the bus, another situation that briefly boosts your heart rate and metabolism.

Anyone who drinks coffee regularly knows that it can be addictive and that large amounts can also cause insomnia, nervousness, and headaches (Chawla et al 2006). It's also a diuretic, which causes your body to lose water and other fluids, all of which you need to maintain a healthy pregnancy.

Tea and coffee can also hamper your body's ability to absorb iron if you drink it with a meal or within half an hour of a meal (FSA n.d. b).

Which foods and beverages contain caffeine?

Caffeine can be found in coffee, tea, colas, and chocolate. Some over-the-counter drugs, including headache and cold tablets, stay-awake medications, and allergy remedies also contain caffeine. Always seek your pharmacist's advice before you buy over-the counter remedies, and don't forget to mention that you are pregnant.

Even the amount of caffeine in coffee and tea can vary widely depending on whether the coffee grounds or tea leaves are brewed or instant, weak or strong. Colas and other drinks vary in caffeine content, too. See the list below for average caffeine amounts in some common foods and beverages (FSA n.d. b). You might be surprised how easily you can get a large dose of caffeine.
• 1 mug of instant coffee = 100mg
• 1 cup of instant coffee = 75mg
• 1 cup of brewed coffee = 100mg
• 1 cup of tea = 50mg
• 1 can of cola = 40mg
• 1 can of "energy" drink = 80mg
• 1 x 50g bar of plain chocolate = up to 50mg
• 1 x 50g bar of milk chocolate = up to 25mg

I'd like to kick the caffeine habit - just to be safe. Any tips?

You may find your taste buds do the cutting back for you. Many women find their fondness for a cup of coffee evaporates during the first trimester when their sense of taste changes and nausea can strike.

Otherwise, to reduce the caffeine in homemade hot beverages, brew them for a shorter time. If you love a soothing cup of Earl Grey, steeping your tea bag for just one minute instead of five reduces the caffeine by as much as half. Many tea companies now offer decaffeinated black or green teas.

Although herb teas often have no caffeine, make sure you read the ingredients list. You'll want to avoid large amounts of caffeine as well as certain herbs and additives that may not be safe during pregnancy. (Read more on the safety of herbs in pregnancy.)

If you're a devoted coffee or cola fan, caffeine withdrawal isn't easy. To minimise symptoms, which include headaches, fatigue, weakness and drowsiness, ease off gradually (Chawla et al 2006). Cut back by half a cup of the beverage each day. You can also try switching from freshly brewed to instant coffee.

If coffee fills an emotional need, such as your private coffee break, or it's an early morning ritual or the perfect end to a meal, you could switch to a cup of decaffeinated coffee or tea. If you're hankering for an ice-cold cola, reach for the caffeine-free version at least some of the time or, better yet, try a glass of mineral water with a dash of lime cordial.