Water Intake During Pregnancy: How Much Should You Drink?

Pregnancy transforms virtually every system in your body, and your hydration needs are no exception. The American College of Obstetricians and Gynecologists recommends that pregnant women drink at least 8 to 12 cups (2.3 to 3 litres) of water per day, but the reality is more nuanced than a single number. Your trimester, body weight, activity level, climate, and whether you are experiencing morning sickness all influence how much water you actually need.

This comprehensive guide covers everything expectant mothers need to know about hydration during pregnancy, from the science behind increased water needs to practical strategies for hitting your daily target even when water makes you nauseous.

Why Pregnancy Dramatically Increases Your Water Needs

During pregnancy, your body undergoes remarkable changes that significantly increase its demand for water. Understanding why you need more fluids helps motivate the effort to drink consistently.

Blood Volume Expansion

One of the most dramatic changes during pregnancy is the expansion of blood volume. By the third trimester, your blood volume increases by approximately 45-50%, which translates to about 1.5 extra litres of blood circulating through your body. This expanded blood supply delivers oxygen and nutrients to the developing baby through the placenta. Manufacturing this additional blood requires a substantial increase in fluid intake.

Amniotic Fluid Production

The amniotic fluid that surrounds and protects your baby is primarily composed of water. By week 36 of pregnancy, there is approximately 800-1000 ml of amniotic fluid in the uterus. This fluid is continuously produced and recycled, requiring a steady supply of water from the mother's intake.

Increased Metabolic Rate

Pregnancy increases your basal metabolic rate by 15-20%, meaning your body burns more energy at rest. This elevated metabolism produces more metabolic waste products that need to be flushed out through urine, requiring more water. It also generates more heat, leading to increased perspiration even in comfortable temperatures.

Supporting Fetal Development

Water is essential for the formation of the placenta and the delivery of nutrients to the fetus. It also supports the production of breast tissue and the preparation of the body for lactation. Every cell your baby develops requires water as a building block.

How Much Water to Drink Each Trimester

Water needs evolve as your pregnancy progresses. Here is a trimester-by-trimester breakdown.

First Trimester (Weeks 1-12)

Recommended intake: 2.0-2.5 litres per day

During the first trimester, your blood volume has not yet expanded significantly, so your water needs are only moderately higher than pre-pregnancy levels. However, this is often the most challenging trimester for hydration due to morning sickness.

Nausea and vomiting can make it difficult to keep fluids down. If you are struggling with morning sickness, try these strategies:

• Sip small amounts frequently rather than drinking large glasses at once
• Try ice chips or frozen fruit (watermelon, grapes) if liquid water triggers nausea
• Drink between meals rather than with meals
• Ginger tea can settle the stomach while providing hydration
• Keep a water bottle by your bed and sip before getting up in the morning
• Try sparkling water or water with lemon if still water is unappealing

If vomiting is severe and you cannot keep any fluids down for more than 12 hours, contact your healthcare provider. Severe dehydration in the first trimester can require intravenous fluids.

Second Trimester (Weeks 13-26)

Recommended intake: 2.5-3.0 litres per day

The second trimester is often called the "golden trimester" because morning sickness typically subsides while energy levels improve. This makes it the ideal time to establish strong hydration habits that will carry you through the third trimester and beyond.

During the second trimester, your blood volume is expanding rapidly and amniotic fluid production is increasing. You may notice increased thirst, which is your body's natural signal to drink more. Listen to it.

This is also when many women begin experiencing leg cramps, especially at night. While not exclusively caused by dehydration, inadequate fluid intake (along with electrolyte imbalances) is a major contributing factor. Ensuring adequate water intake, along with sufficient magnesium and potassium, can significantly reduce cramping. For more on how hydration affects muscle function, see our guide on hydration for runners.

Third Trimester (Weeks 27-40)

Recommended intake: 2.5-3.5 litres per day

The third trimester brings the highest hydration demands. Your blood volume peaks, amniotic fluid is at its maximum, and the baby is growing rapidly. Many women also experience increased swelling (edema) in the hands, feet, and ankles during this period.

Counterintuitively, drinking more water actually helps reduce swelling. Edema is partly caused by your body retaining water when it senses dehydration. By staying well-hydrated, you signal to your body that it does not need to hold onto excess fluid.

Frequent bathroom trips are unavoidable in the third trimester as the baby presses on the bladder. Do not reduce your water intake to avoid trips to the bathroom. Instead, front-load your intake earlier in the day and reduce slightly in the 2-3 hours before bedtime to minimise nighttime disruptions.

How Dehydration Affects Your Baby

Dehydration during pregnancy is not just uncomfortable for the mother — it can have direct consequences for the developing baby.

Reduced Amniotic Fluid (Oligohydramnios)

Chronic dehydration can lead to low amniotic fluid levels, a condition called oligohydramnios. Amniotic fluid is critical for fetal lung development, cushioning against physical impact, maintaining a stable temperature, and allowing the baby to move and develop muscles. Low amniotic fluid is associated with birth complications and may require medical intervention.

Neural Tube Defects

Adequate hydration supports the proper formation of the neural tube during the critical early weeks of pregnancy. While folic acid is the primary preventive measure, dehydration can impair the absorption of vitamins and nutrients necessary for healthy fetal neural development.

Preterm Labour

Severe dehydration is a known trigger for preterm contractions. When the body is dehydrated, it produces higher levels of oxytocin, the hormone that stimulates uterine contractions. In fact, one of the first things healthcare providers do when a pregnant woman presents with premature contractions is administer intravenous fluids, which often stops the contractions entirely.

Reduced Breast Milk Production

Dehydration in late pregnancy and the postpartum period can impair breast milk production. Establishing good hydration habits during pregnancy sets the foundation for successful breastfeeding.

The Best Fluids to Drink During Pregnancy

Not all fluids are created equal when you are expecting. Here is a guide to the best and worst options.

Best Choices

• Water — The gold standard. Clean, calorie-free, and exactly what your body needs most.
• Coconut water — Natural source of electrolytes (potassium, magnesium) that can help with hydration and leg cramps. Choose unsweetened varieties.
• Herbal teas — Ginger tea helps with nausea, peppermint tea aids digestion, and rooibos tea is caffeine-free and antioxidant-rich. Avoid herbal teas containing liquorice root, sage, or parsley in large amounts.
• Milk — Provides hydration along with calcium and protein essential for fetal bone development.
• Fruit-infused water — Adding berries, citrus, cucumber, or mint to water makes it more appealing and can help if plain water triggers nausea.
• Broth and soup — Excellent for hydration and nutrition, especially during the first trimester when solid foods may be difficult to tolerate.

Drinks to Limit

• Coffee and caffeinated tea — The current recommendation is to limit caffeine to 200 mg per day (about one 350 ml cup of coffee). Caffeine crosses the placenta and the fetus cannot metabolise it efficiently.
• Fruit juice — High in natural sugars and calories. If you drink juice, dilute it 50/50 with water.
• Sugary drinks and sodas — Provide hydration but also excessive sugar that can contribute to gestational diabetes and excessive weight gain.

Drinks to Avoid

• Alcohol — No amount of alcohol is considered safe during pregnancy. It crosses the placenta and can cause fetal alcohol spectrum disorders.
• Energy drinks — Often contain excessive caffeine, taurine, and other stimulants that are not safe for pregnant women.
• Unpasteurised juices — May contain harmful bacteria (Listeria, E. coli) that pose serious risks during pregnancy.

Practical Hydration Tips for Pregnant Women

Use a Tracking Tool

Pregnancy brain is real. Between prenatal appointments, nursery preparation, and the physical demands of growing a baby, remembering to drink water can easily fall through the cracks. A tracking tool like WaterPing provides a visual reminder of your progress throughout the day. Set your goal to your trimester-specific target and log each drink with a single tap. The progress ring fills up as you drink, giving you a satisfying visual confirmation that you are on track.

Front-Load Your Intake

Drink the majority of your water earlier in the day. Aim to consume 60-70% of your daily target before 3pm. This reduces the frequency of nighttime bathroom trips while ensuring you still hit your goal. A good schedule might look like:

• 7am: 500 ml upon waking
• 10am: 400 ml
• 12pm: 400 ml with lunch
• 3pm: 400 ml
• 5pm: 300 ml with dinner
• 7pm: 200 ml (tapering off before bed)

Carry a Marked Water Bottle

A 1-litre bottle with time markers creates a visual pace for your drinking. Many pregnancy-specific water bottles include motivational messages at each marker. Filling and emptying this bottle 2-3 times per day ensures you meet your target.

Eat Hydrating Foods

Water-rich foods contribute approximately 20% of your daily fluid intake. Incorporate these into your pregnancy diet:

• Watermelon (92% water) — also a good source of vitamin C and lycopene
• Cucumber (96% water) — low-calorie snack that pairs well with hummus
• Strawberries (91% water) — rich in folate, which is crucial during pregnancy
• Oranges (87% water) — excellent source of vitamin C and folate
• Yoghurt (85% water) — provides calcium and probiotics

Set Reminders

Use your phone or a tool like WaterPing to send reminders every 1-2 hours during the day. Consistent small amounts are better than trying to catch up with large volumes at the end of the day.

Hydration During Labour and Postpartum

During Labour

Staying hydrated during labour is crucial for maintaining energy and supporting uterine function. Many hospitals allow clear fluids during early labour, including water, ice chips, and clear juice. Discuss your hospital's policy with your birth team in advance. If you are planning a natural birth, having a supportive partner who offers sips of water between contractions can make a significant difference.

Postpartum and Breastfeeding

After delivery, your hydration needs remain elevated, especially if you are breastfeeding. Breast milk is approximately 87% water, and producing it requires an additional 500-700 ml of fluid per day on top of your normal baseline. Most lactation consultants recommend that breastfeeding mothers drink at least 3-3.5 litres per day.

A helpful habit is to drink a glass of water every time you breastfeed or pump. Since newborns feed 8-12 times per day, this simple habit can contribute 2-3 litres toward your daily goal.

Frequently Asked Questions

Can dehydration cause miscarriage?

Severe dehydration can contribute to complications that increase miscarriage risk, including reduced blood flow to the uterus and electrolyte imbalances. However, it is important to note that most miscarriages are caused by chromosomal abnormalities and are not related to hydration. That said, staying well-hydrated supports a healthy pregnancy and reduces the risk of many preventable complications.

I cannot keep water down due to morning sickness. What should I do?

Try very small, frequent sips rather than full glasses. Ice chips, frozen fruit, and popsicles can be easier to tolerate. Ginger tea, lemon water, and sparkling water may be less likely to trigger nausea than plain still water. If you cannot keep any fluids down for more than 12 hours, or if you notice dark urine, dizziness, or a rapid heartbeat, contact your healthcare provider immediately. You may have hyperemesis gravidarum, which sometimes requires intravenous fluids.

Is sparkling water safe during pregnancy?

Yes. Sparkling water (plain carbonated water without added sweeteners) is perfectly safe during pregnancy and counts fully toward your daily hydration goal. Some women find the carbonation helps settle their stomach during episodes of nausea. Avoid sparkling waters that contain added sugars, artificial sweeteners, or excessive sodium.

How do I know if I am dehydrated during pregnancy?

The easiest indicator is urine colour. Aim for pale yellow or straw-coloured urine. Dark yellow or amber urine indicates you need to drink more. Other signs include dry mouth, headache, fatigue, dizziness, reduced urine output (fewer than 4 bathroom visits per day), and dry skin. If you experience any of these symptoms alongside rapid heartbeat or fainting, seek medical attention.

Should I drink more water if I have gestational diabetes?

Yes. Women with gestational diabetes are at higher risk of dehydration because elevated blood sugar levels cause the kidneys to excrete more water. Aim for the upper end of the recommended range (3-3.5 litres per day) and monitor your urine colour closely. Proper hydration also helps with blood sugar regulation, creating a positive cycle.

Your Hydration Plan Starts Now

Staying hydrated during pregnancy is one of the simplest and most impactful things you can do for both your health and your baby's development. The key is consistency — drinking small amounts throughout the day rather than trying to catch up in large bursts.

WaterPing makes pregnancy hydration effortless. Set your trimester-specific daily goal, log every drink with one tap, and watch your progress ring fill up throughout the day. The free tier includes unlimited logging and reminders, so you never have to wonder whether you have had enough water. No download, no account — just open it in your browser and start hydrating for two.

Try WaterPing free today and give your baby the hydration foundation they deserve.