High Temperature in Pregnancy

Call now if

This section is first because a temperature in pregnancy is not a symptom to sit with overnight.

Contact your GP, midwife or hospital maternity unit if your temperature is above 37.5C, even if you have no other flu or cold symptoms. That is Tommy's instruction, published for pregnancy specifically, and it repeats the sentence twice on the same page.

Call 999 and say you suspect sepsis if you have any of the signs Tommy's lists: fast breathing, slurred speech, seeming confused, clammy, blotchy or mottled skin that can look bluish on some skin tones, a rash that does not fade when you press a glass on it, not having a wee all day, or feeling very drowsy.

The HSE names a fever in the third trimester — "a temperature of 38 degrees Celsius or higher" — among the reasons to contact your GP, maternity unit or hospital, because it could be a sign of infection.

Why there are two numbers

The NHS defines a high temperature in adults generally as 38C or above, and lists the signs as feeling hotter than usual, shivering (chills), or a thermometer reading of 38C or more.

Tommy's uses 37.5C for pregnancy and explains the gap directly: "A high temperature is 38C or above. But even 37.5C could be a sign of a hidden infection. Some infections can make you really unwell, or harm your unborn baby, so it is important to get checked out."

The lower threshold is not a different fact; it is a lower bar for asking, because the consequences of a missed infection in pregnancy are worse. Use 37.5C.

A temperature is a symptom, not a diagnosis

Tommy's puts it this way: "A high temperature is a symptom of an underlying issue, rather than an illness." The common signs that come with it are chills (shivers and feeling cold), sweating, a headache, fatigue and muscle aches.

The point of the phone call is not to treat the number. It is to find what is driving it. Tommy's names the usual candidates: a cold, flu, COVID-19 or a urinary tract infection, and rarely something more serious such as sepsis.

Urine infection

UTIs are common in pregnancy and are the cause that most often hides behind a temperature with no obvious cough or cold. Tommy's notes that they are easy to diagnose from a wee sample, that your midwife will offer to test your wee at each appointment, and that your midwife, GP or a sexual health clinic can test at any time if you have symptoms. Treatment is a course of antibiotics.

The NHS lists pregnancy as a reason to ask for an urgent GP appointment with UTI symptoms rather than trying self-care, and names a very high temperature, or feeling hot, cold or shivery, among the signs that an infection may have reached a kidney.

Flu

Tommy's is specific here: "A sudden high temperature may be a sign of flu. Pregnancy puts you in the 'at risk' category from flu. That means you are more likely to get very ill with flu than other people are." It advises talking to your GP, midwife or maternity unit as soon as possible if you think you have flu, even if you have had the flu jab, because antiviral treatment is time-limited.

Sepsis

Sepsis is the reason the advice on temperature in pregnancy is more insistent than it is for anyone else. Tommy's describes it as the immune system attacking healthy tissue in response to an infection, notes that it is serious and needs treating quickly, and gives it a name in this context: maternal sepsis, meaning sepsis affecting someone during pregnancy or up to six weeks after birth.

It also flags the counter-intuitive part: "A high or very low temperature can also be a sign of something called sepsis." A temperature that has dropped below normal is not reassurance.

What to do while you are waiting to be seen

• Take your temperature properly. A thermometer costs very little at a pharmacy or supermarket and removes all the guesswork from this page.
• Drink plenty of water. Tommy's names this alongside paracetamol.
• Paracetamol. Tommy's says it is safe to take in pregnancy and can help bring your temperature down. Follow the packet and ask your midwife or pharmacist if you are unsure. Do not combine it with cold and flu remedies that also contain paracetamol.
• Avoid ibuprofen and decongestants. Tommy's names both among painkillers and remedies you should not take while pregnant, and decongestants are exactly what people reach for when a temperature comes with a blocked nose.

Tommy's adds the sentence that keeps this in perspective: "Depending on why you have a fever, paracetamol may not cure the reason for your temperature." Bringing the number down makes you feel better. It does not treat what caused it.

What happens when you ring

Which number to ring depends on how many weeks you are. The NHS sets it out as: your GP surgery or an early pregnancy unit in the first 12 weeks; your midwife or an early pregnancy unit from 12 to 19 weeks; your midwife or maternity unit from 20 weeks. Always call 999 for anything you think is life-threatening, at any stage, and NHS 111 if you are unsure or services are closed.

Expect to be asked about your temperature, any pain on peeing, any cough or cold symptoms, your baby's movements, and whether you feel shivery. Expect a urine sample. None of this is an overreaction; a temperature in pregnancy is one of the few symptoms where the guidance from every body says the same thing, which is to ask early.