Fluids in pregnancy

Fluids: Essential for life

A huge proportion of the human body is made up of water. It keeps our complex systems working properly, while helping us absorb nutrients and flush out toxins.

During pregnancy, the increased demands on your body mean you need more water than usual to meet these increased requirements and avoid dehydration.

Water and your pregnant body

Some of the most crucial support systems for your baby involve a significant amount of water. For a start, your blood volume that supplies their oxygen, for instance, increases by 50%. The amniotic fluid, which provides nourishment and cushioning for your baby while supporting their growth, is also made up of mostly water.

Getting sufficient fluids each day will help to maintain these life-sustaining systems, while stopping you becoming dehydrated.

In combination with a diet rich in fibre, fluids can help reduce your likelihood of constipation, and the piles (haemorrhoids) that sometimes come along with it.

When you can’t keep water down

If you’re having trouble keeping fluids down due to morning sickness or a stomach upset, try to take small sips regularly rather than large gulps. Even small amounts add up and can lower your risk of becoming dehydrated; so start by taking small sips and gradually increase the amount if you can.

You may also find that drinking fluids at room temperature, rather than ice cold, helps. Some mums find that soups and broths can be kept down, while others stay hydrated with milk or sugar-free squash. It’s a case of trial and error, but any fluid is better than no fluid at all.

In prolonged cases, let your GP or midwife know. They may prescribe something to ease your sickness or, in extreme cases, admit you to hospital to receive fluids through an IV drip.

When you start breastfeeding, how much more fluid will you need each day?

What and how much to drink when pregnant

Although your need for water increases during pregnancy, there is no single recommended amount because every person is different. Various factors including body weight and activity level affect how much you will need per day. 

The European Food Safety Authority (EFSA) advises that non-pregnant women need around 2 litres of water a day, which is equivalent to ten 200ml glasses. However, this also includes water from all fluids and foods. During pregnancy, EFSA estimate that you will need at least this amount and around an extra 300ml to avoid dehydration. 

Suitable drinks for pregnancy include water, whether straight from the tap (if safe in your area), or bottled (either carbonated or still), milk, fruit juices and sugar free squash. Juice can be high in sugar, but providing it’s pure fruit, one 150ml glass can also count as part of your daily 5-a-day fruit and vegetable intake. Soup also counts, and can provide a good serving of beneficial nutrients too.

Try to avoid drinks that are fizzy or high in sugar. With little nutritional value, it’s best to avoid them or try a healthier alternative^.

You should also limit your intake of caffeinated varieties of tea and coffee. Caffeine can act as a diuretic, increasing your need to urinate, and can also affect your baby. Because of this, it’s on the list of foods to limit or avoid in pregnancy, and it’s recommended that you have no more than 200mg per day.

Preparing to drink for two

As you start looking ahead to breastfeeding, you can consider the extra fluid intake you need during pregnancy to be good practice for the even bigger demands of making breast milk.

Research shows that while breastfeeding, your need increases even more to keep your own body hydrated and to provide the water required to produce a good supply of milk. EFSA advise to drink around 700ml extra per day when you are breastfeeding – equivalent to 3-4 glasses^.

Many mums find that as soon as they sit down to breastfeed, they feel thirsty. This helpful response can make it easier to stay hydrated with enough fluids to support you both. Keep a big glass of water within reach when feeding your baby, day or night.