25 August 2026 · Veronica Chi
Business & Product Director · Mum of two
How Much Water Do Pregnant Women Need?
The commonly cited figure is around 8 to 10 glasses a day — roughly 2 to 2.4 litres of total fluid — increasing in hot weather, with exercise, and while breastfeeding afterwards. It is a reasonable starting point and a poor stopping point, because requirements vary enormously with climate, activity and body size.
A better measure than counting
Urine colour. Pale straw means well hydrated. Dark yellow or amber means drink more. It is immediate, free, and adjusts automatically for a hot day or a long walk in a way that a fixed target cannot.
One caveat: prenatal vitamins containing B vitamins can turn urine bright yellow regardless of hydration. If you take them, judge by thirst, energy and how often you are going instead.
Why it matters more in pregnancy
- Blood volume increases by roughly 40 to 50 per cent, and that volume needs fluid.
- Amniotic fluid is produced continuously and is affected by maternal hydration.
- Kidneys are processing waste for two, at a higher filtration rate.
- Constipation is extremely common in pregnancy, and fluid plus fibre is the first-line answer.
- Urinary tract infections are more common, and being well hydrated reduces the risk. UTIs in pregnancy need prompt treatment because untreated they can trigger preterm labour.
- Dehydration can cause Braxton Hicks contractions, which is a frequent and avoidable reason for a trip to triage.
Signs of dehydration worth acting on
- Dark urine, or passing urine much less often than usual.
- Headache, dizziness or feeling faint.
- Dry mouth, cracked lips, unusually dry skin.
- Feeling unusually tired or foggy without another explanation.
- Braxton Hicks tightening that eases after you drink and rest.
- In heat: not sweating despite feeling hot, which is a serious sign and needs medical attention.
Drinking when everything makes you sick
First-trimester nausea makes water taste metallic for many women, and the advice to drink more is unhelpful when swallowing is the problem. Practical workarounds:
- Small sips constantly rather than a glass at a time. A large volume at once is the most likely to come back.
- Very cold water, or ice chips and ice lollies. Cold suppresses taste and is often tolerated when room-temperature water is not.
- Add lemon, mint or cucumber — the metallic taste is often the specific complaint, and flavour masks it.
- Sparkling water, which many find easier than still.
- Eat your fluid: watermelon, cucumber, soup, yoghurt. Food contributes a meaningful share of total intake.
- Use a straw, which reduces the amount you smell while drinking.
If you cannot keep fluids down at all for more than a day, are losing weight, or are passing very little urine, contact your midwife or doctor. Hyperemesis gravidarum is a medical condition rather than bad luck, and it is treatable.
What counts, and what to limit
- Water, milk, decaffeinated tea and coffee, and diluted squash all count. So does the water in food.
- Caffeine should stay under 200mg a day in pregnancy — roughly two mugs of instant coffee, or one filter coffee. Remember that tea, cola, energy drinks and chocolate contribute.
- No alcohol. There is no established safe amount.
- Herbal teas are not automatically safe in pregnancy; some are advised against. Check specific ones rather than assuming.
- Sports drinks are unnecessary unless you have been vomiting or exercising hard, in which case they are useful.
A note on swelling
Mild swelling of feet and ankles is normal in later pregnancy, and drinking less water does not help — it usually makes fluid retention worse. But sudden or severe swelling of the face, hands or feet, especially with headache, visual disturbance or pain below the ribs, needs urgent assessment, because those are signs of pre-eclampsia.
Questions parents ask
How much water should a pregnant woman drink a day?
Around 8 to 10 glasses, or 2 to 2.4 litres of total fluid, and more in hot weather or with exercise. Urine colour is a better guide than any fixed number — pale straw means well hydrated.
How can I drink more water when pregnancy nausea makes it taste metallic?
Small constant sips rather than glasses, very cold water or ice lollies, lemon or mint to mask the taste, sparkling water, and eating fluid-rich foods like watermelon, cucumber and soup. A straw reduces the smell while drinking.
Does drinking less water reduce pregnancy swelling?
No — it usually makes fluid retention worse. Mild ankle and foot swelling is normal later in pregnancy. Sudden or severe swelling of the face and hands, particularly with headache or visual changes, needs urgent assessment for pre-eclampsia.
How much caffeine is safe in pregnancy?
Under 200mg a day, roughly two mugs of instant coffee or one filter coffee. Tea, cola, energy drinks and chocolate all contribute to the total, which is easy to overlook.
Sources
This guide is general information, written to help you understand a topic and ask better questions — it is not medical advice and does not replace your own doctor, midwife or paediatrician. Anything that worries you about your baby belongs with them.