Safe Drinking Water During Pregnancy: What to Drink

Safe Drinking Water During Pregnancy: What to Drink, What to Avoid and Why It Matters starts with one simple rule: drink water that has been tested and treated for both germs and chemical contaminants. In Bangladesh, this may mean using certified RO+UV water, especially where arsenic, lead, nitrate or fluoride is a concern.

Pregnancy is not a reason to panic about every glass of water. It is a reason to know your source, understand its risks and choose treatment that matches those risks. If you are unsure about your water quality, ask your obstetrician or a qualified water-testing service for advice.

Why Safe Drinking Water During Pregnancy Matters

Pregnancy changes how the body handles fluids and some contaminants. Blood volume rises by about 50% during pregnancy, while the placenta allows many dissolved substances to reach the developing baby.
 Arsenic, lead, nitrates and certain organic pollutants can cross the placenta.

The foetal liver and kidneys are still developing, so the baby has less ability to process and remove harmful substances. This is why contaminated water can affect more than the mother. 
Exposure may influence brain development, organ formation, birth weight and other pregnancy outcomes.

Waterborne infections also matter. Pregnancy involves immune changes that help support the pregnancy but can increase vulnerability to some infections. Severe illness from contaminated water may lead to dehydration, hospitalisation or complications for the mother and baby.

“There is no safe level of lead exposure.” — World Health Organization, Lead poisoning and health

How Much Water Do You Need During Pregnancy?

A common general guide is about 2.5 to 3 litres of total fluid per day during pregnancy. This includes water and fluid from drinks and foods, not only plain water. The National Academies has commonly cited an increase of about 300 millilitres of water per day during pregnancy, but individual needs vary.

Hot weather, sweating, vomiting, diarrhoea, exercise and breastfeeding after birth can increase fluid needs. In Bangladesh, the hot season from March to June may make dehydration more likely. Drink regularly rather than waiting until you feel very thirsty, and speak with a clinician if you cannot keep fluids down or have signs of dehydration.

Use these practical steps to choose and protect safe drinking water during pregnancy:

1. Identify your water source. Note whether you use municipal water, a tube well, groundwater, bottled water or a private treatment system.
2. Test for local risks. Check for arsenic, lead, nitrate, fluoride and disease-causing microorganisms, especially if you use groundwater or live in an area affected by flooding.
3. Match treatment to the contaminant. Boiling or UV can reduce germs, but they do not remove arsenic, lead, nitrate or fluoride. Use a certified filter or RO system designed for the specific chemical risk.
4. Drink regularly. Aim for roughly 2.5–3 litres of total daily fluids from drinks and foods, adjusting for heat, exercise, vomiting or diarrhoea according to your clinician’s advice.
5. Choose beverages carefully. Prefer tested water and limit sugary drinks, excessive caffeine and unverified herbal remedies during pregnancy.
6. Prevent recontamination. Store treated water in a clean, covered container and use clean cups or utensils rather than dipping hands into the supply.
7. Ask for medical guidance when needed. Tell your antenatal provider about a confirmed contaminant, unsafe water source, severe vomiting or signs of dehydration.

Safe Drinking Water During Pregnancy: Contaminants to Watch

Arsenic and pregnancy health

Arsenic is a major concern in parts of Bangladesh, particularly where households depend on groundwater. Research in arsenic-affected districts has linked higher prenatal exposure with miscarriage, stillbirth, lower birth weight, impaired cognitive development in childhood and a higher risk of preeclampsia.

Risk depends on the concentration, how often you drink the water and how long exposure continues. A pregnant woman drinking unfiltered groundwater may take in more arsenic each day simply because pregnancy increases her fluid needs.

What to do: Test the source water for arsenic. If testing confirms contamination, use a treatment system independently certified for arsenic removal. Reverse osmosis can help, but do not assume every low-cost purifier removes arsenic; check its performance data and maintain it on schedule.

“In pregnancy, every glass of water is a quiet investment in two lives.”

Lead and irreversible neurological harm

Lead can cross the placenta and harm the developing nervous system. During pregnancy, lead stored in a mother’s bones may return to the bloodstream as the body supplies calcium for foetal bone development. 
This can expose the baby even when the mother has no current industrial exposure.

Possible sources include old plumbing, lead solder in joints and some imported brass fittings. Older buildings in urban areas, including parts of Dhaka, may need extra care. There is no established safe level of lead exposure for a developing foetus.

What to do: Test specifically for lead if you live in an older building or suspect old plumbing. RO systems may remove a high percentage of lead, but performance depends on the device, installation and maintenance. Use only a system with reliable test results.

Nitrates from wells and agricultural runoff

Nitrate can enter groundwater through fertiliser runoff, sewage and animal waste. The clearest danger is methemoglobinemia, sometimes called blue baby syndrome, in infants under 6 months. 
Some studies have also associated high prenatal nitrate exposure with neural tube defects and other birth complications.

Water containing more than 50 mg/L of nitrate is a concern under the threshold used in the original guidance. Boiling does not remove nitrate and may concentrate it as water evaporates.

What to do: Test well water near farms or heavily fertilised land. Choose a treatment method proven to reduce nitrate, such as a properly maintained RO system or another certified option.

Fluoride and high-fluoride areas

Fluoride is useful for dental health at appropriate levels, but long-term exposure above the World Health Organization guideline of 1.5 mg/L can cause dental or skeletal fluorosis. Some research suggests that high exposure during pregnancy may affect foetal neurological development.

Arsenic is more widespread in many Bangladeshi water sources, but natural fluoride can be elevated in certain geological areas, including parts of Rajshahi and Rangpur divisions. Testing is the best way to decide whether fluoride treatment is needed.

Waterborne infections

Untreated water may contain bacteria, viruses or parasites. E. coli and similar bacteria can cause severe diarrhoea and dehydration. Listeria is uncommon in drinking water but can cause miscarriage, premature birth or serious newborn illness. Toxoplasma can also spread through contaminated water and may damage a baby’s brain or eyes.

Boiling is effective against most infectious organisms when done correctly. UV treatment can also control microbes, but only when the water is clear and the system receives proper maintenance. Neither boiling nor UV removes arsenic, lead, nitrate or fluoride.

What to Drink and What to Avoid During Pregnancy

Best option: tested RO+UV water when needed

RO+UV treatment can address two different risk groups: RO may reduce dissolved contaminants such as arsenic, lead, nitrate and fluoride, while UV helps control microorganisms. This combination is useful when testing shows both chemical and microbial risks.

• Use treated water for drinking, tea, ice and all food preparation.
• Use it for washing ingredients that will be eaten raw and for cooking rice, vegetables and soup.
• Check that the purifier is certified for the contaminants found in your water.
• Replace filters and membranes according to the manufacturer’s schedule.
• Test treated water periodically instead of relying only on taste, smell or a TDS meter.

A mineraliser may add calcium and magnesium after RO treatment, but it should not replace a balanced prenatal diet or medical advice. A TDS reading alone cannot confirm that water is free from arsenic, lead or germs.

Boiled water as an interim option

Boiling is a useful emergency or short-term measure when microbial contamination is the main concern. It does not remove arsenic, lead, nitrate or fluoride. In an arsenic-affected area, boiled water is therefore not a complete substitute for a treatment method designed to remove arsenic.

Drinks and water sources to avoid

• Untreated tap water or unfiltered well water when its quality is unknown.
• Water from a source that has not been tested after flooding or changes in colour, smell or taste.
• Bottled water from an unknown supplier or with no clear quality information.
• UV-only treatment where dissolved chemical contamination is possible.
• Unpasteurised drinks or ice made from unsafe water.

For caffeine, herbal drinks and packaged beverages, follow your clinician’s advice. They do not replace safe water, and some drinks may contain more caffeine or sugar than expected.

A Practical Safe Water Plan for Expectant Mothers

1. Identify the source. Record whether your household uses a municipal supply, tube well, private well, bottled water or a shared source.
2. Test before choosing treatment. In high-risk areas, request testing for arsenic, lead, nitrate, fluoride and microbial contamination. A treatment system cannot be selected properly without knowing the problem.
3. Match the treatment. Use certified arsenic or nitrate removal for those contaminants, and boiling, UV or other verified disinfection for microbial risk. RO+UV may be appropriate when both types of risk are present.
4. Protect the treated water. Store it in a clean, covered container and avoid dipping unwashed cups or hands into it. Recontamination can happen after treatment.
5. Tell your healthcare provider. Mention groundwater use, a history of flooding or a confirmed contaminant result at your antenatal visit.

After birth, continue using safe water for formula preparation and baby food. Infants are especially vulnerable to contaminated water, and formula preparation requires careful attention to both water quality and hygiene.

FAQ: Safe Drinking Water During Pregnancy

Is boiled water safe during pregnancy?

Boiled water is generally useful for reducing germs, provided it is boiled correctly and stored safely. It is not enough where arsenic, lead, nitrate or fluoride is present because boiling does not remove those chemicals.

Can pregnant women drink bottled water?

Yes, if the product comes from a trustworthy supplier and meets local safety standards. Bottled water is not automatically safer than treated tap water, and a bottle does not prove that every batch has been tested for arsenic or other contaminants.

Does a UV purifier remove arsenic?

No. UV treatment targets microorganisms, not dissolved chemicals. If arsenic, lead, nitrate or fluoride is a concern, you need a treatment method specifically tested for that contaminant, often alongside disinfection.

What is the safest water for making baby formula?

Use water from a tested, properly maintained and suitable treatment system. Follow the formula manufacturer’s mixing instructions and your paediatrician’s advice. Safe storage and clean bottles matter as much as the water source.