Fever in Labour

The two numbers

NICE names them twice in its intrapartum guideline, once for the initial assessment and once for the hourly risk assessment during labour, in identical terms. Transfer to obstetric-led care is recommended for a "temperature of 38°C or above on a single reading, or 37.5°C or above on 2 consecutive readings 1 hour apart".

That is why your temperature is taken four-hourly as part of the standard observations in established labour, alongside blood pressure and respiratory rate, with an hourly pulse. A single slightly raised reading is a reason to repeat it in an hour, not a reason to panic.

NICE also points teams to its guidance on intrapartum antibiotics for neonatal infection at the same point in the text, which tells you what the concern is: not the fever itself, but infection reaching the baby.

What causes a fever in labour

Several things, and they are not equally serious.

Infection in the uterus or membranes. The concern that drives the guideline. It becomes more likely the longer the membranes have been broken. NICE treats rupture of membranes more than 24 hours before the onset of established labour as its own trigger for obstetric-led care, and asks that babies born after prolonged rupture at term be observed closely for the first 12 hours of life.

Infection elsewhere. A urine infection, a chest infection, or a viral illness you already had when labour started.

An epidural. A modest rise in temperature is a recognised association with epidural analgesia in labour. It is not an infection, but it is not distinguishable from one at the bedside, which is precisely the problem it creates.

Being too hot. A warm room, a birthing pool above a comfortable temperature, or heavy blankets. The NHS notes that water in a pool is kept at a comfortable temperature "but not above 37.5C, and your temperature will be monitored" — the monitoring exists because heat matters.

Dehydration and long labour. Both can nudge a temperature up.

Nobody at the bedside can reliably tell these apart in the moment. That is the honest reason a fever is treated cautiously rather than watched.

What changes when it happens

The realistic sequence, all of which follows from NICE's recommendations rather than local habit:

• The reading is repeated, and your pulse, blood pressure and respiratory rate are rechecked.
• If you are in a midwifery-led setting, transfer to obstetric-led care is discussed. NICE frames it as a discussion and asks teams to explain the reasons, address concerns and obtain informed consent.
• Continuous monitoring of the baby's heart rate is likely to be recommended, because maternal fever is one of the risk factors NICE's fetal monitoring guideline weighs.
• Bloods and a urine sample may be taken, and a source looked for.
• Antibiotics may be offered, and paracetamol to bring the temperature down.
• If you are in a pool, you will be asked to come out.

NICE's guideline on intrapartum care for women with existing medical conditions covers suspected sepsis in labour in more detail, including that a birthing pool should only be considered as analgesia after discussion with a senior midwife and senior obstetrician where sepsis is suspected but antibiotics are not yet warranted.

Why the baby is watched afterwards

A raised maternal temperature is one of the recognised risk factors for early-onset neonatal infection, which is why the plan continues after the birth. Babies in this situation are usually observed rather than treated, with antibiotics started if there is a specific concern.

NICE lists the newborn observations that matter in similar circumstances: respiratory rate, heart rate, grunting, recession, temperature, capillary refill, oxygen saturation and colour. A temperature of 38°C or above in the baby, or 37.5°C on two occasions 15 to 30 minutes apart, prompts assessment by a neonatologist.

Sepsis: the word nobody wants to say

Most fevers in labour are not sepsis. But sepsis in and around pregnancy is one of the situations where speed changes outcomes, which is why a temperature in labour is acted on at 38°C rather than watched. In hospital you already have staff and four-hourly observations around you, and the fever is being investigated before you have to argue for it.

The signs that matter most are the ones that appear alongside a temperature rather than the temperature itself: confusion or slurred speech, breathing very fast, skin that has turned pale or blotchy, or simply feeling suddenly and strangely unwell. The NHS publishes the full emergency list for adults, and it is worth reading before you go home rather than after, because once you are discharged you are the person who notices first.

In hospital, you already have staff and observations around you. The value of knowing these signs is for after you go home, when you are the one who notices first.

Afterwards

Fever does not stop at the birth. NICE's postnatal guideline asks midwives to assess for signs of infection at every contact, and lists "abdominal, pelvic or perineal pain, fever, shivering, or vaginal discharge with an unpleasant smell" among the symptoms that should prompt seeking medical advice without delay.

The HSE's guidance on when to get medical help after the birth carries the same list for women in Ireland. A temperature that appears on day three at home is not a continuation of labour — it is a new event, and it deserves the same phone call.

What to ask

What is my temperature, and is it one reading or two? What do you think is causing it? Are we treating it or watching it? Does this change what happens to my baby after the birth? If I am being moved, what exactly changes about my care once I get there?

A fever is one of the commonest reasons a birth plan changes mid-labour, and it is one of the easiest to understand once the numbers behind it are visible. Being told "your temperature is up" without the threshold attached is what makes it frightening.