Can't Keep Water Down in Pregnancy: What to Do

When it becomes serious

Being unable to keep water down in pregnancy is one of the clearest warning signs of hyperemesis gravidarum (HG) or another serious cause of vomiting. While ordinary morning sickness is unpleasant, vomiting so severely that you cannot stay hydrated is not something to "push through". The NHS recommends seeking help within 12-24 hours if you cannot keep fluids down.

What is happening in your body

When you cannot replace the fluids you are losing through vomiting, you become dehydrated. Your blood volume drops, your kidneys produce less urine, and electrolytes (sodium, potassium, chloride) become unbalanced. Your body also begins breaking down fat for energy, producing ketones - which show up in your urine and make nausea worse, creating a vicious cycle.

Signs you need help now

Go to your GP, maternity assessment unit, or call NHS 111 if you notice:

• You have not kept any fluid down for 12 hours or more
• Your urine is very dark or you have not passed any for 8 hours
• You feel dizzy, faint or weak when standing
• Your heart races or feels irregular
• You have a dry mouth, cracked lips or sunken eyes
• You feel confused, drowsy or unable to concentrate
• You have lost weight rapidly since your last appointment

If you have severe abdominal pain, are vomiting blood, or feel very unwell, go to A&E or call 999.

What treatment involves

At hospital or a maternity assessment unit you can expect:

1. Blood tests - checking electrolytes, kidney function and ketones
2. Urine test - looking for ketones
3. IV fluids - saline, often with added potassium, to rehydrate you
4. IV anti-sickness medication - cyclizine or ondansetron to break the vomiting cycle
5. Thiamine - if vomiting has lasted more than a week, to prevent rare neurological problems

Most women feel much better after fluids, though some need to stay overnight.

What to try at home - carefully

Before you reach the 12-hour mark, try:

• Tiny sips of water, oral rehydration salts, or flat lemonade - a sip every 5-10 minutes
• Ice cubes to suck, or frozen electrolyte lollies
• Cold drinks - these often smell less than hot food
• Small, dry snacks like crackers or plain toast
• Rest in a quiet, cool room away from food smells

If these measures do not work within a few hours, seek help. Waiting too long makes recovery harder.

Red-flag causes beyond HG

Sometimes vomiting in pregnancy has other causes that need urgent investigation:

• Urinary tract infection (common in pregnancy)
• Thyroid disorder - overactive thyroid can worsen vomiting
• Gallstones or liver conditions such as obstetric cholestasis
• Multiple pregnancy - twins or more raise hormone levels
• Molar pregnancy - rare but important to exclude

Your hospital team may arrange an ultrasound and further blood tests to rule these out.

After treatment

Once home:

• Continue any prescribed anti-sickness medication on schedule
• Reintroduce fluids and foods gradually
• Ask your midwife about community IV services - some NHS trusts offer outpatient hydration
• Request a follow-up appointment within a few days

You are not overreacting

Vomiting that stops you drinking is a medical concern, not a normal pregnancy symptom. Reaching out for IV fluids early can prevent days of suffering and serious complications. Ask for help - that is what maternity services are there for.