Call your maternity unit immediately if

This comes first, before any reassurance, because painful movements and reduced movements get muddled and only one of them is urgent.

The NHS puts it in an urgent-advice box. Call your midwife or maternity unit immediately if:

your baby is moving less than usual
you cannot feel your baby moving any more
there is a change to your baby's usual pattern of movements

And the instruction people most often override: "Do not wait until the next day — call immediately, even if it's the middle of the night."

Tommy's adds the weakening version, which is easy to talk yourself out of: contact your maternity unit immediately if you think your baby is moving less, "their movements feel weaker" or they have stopped moving. It also says something worth remembering on a night when you cannot articulate what is wrong: "You should also contact your maternity unit if you just feel something is wrong, even if you can't explain exactly why you think that."

The NHS is explicit about one thing not to do: "Do not use a home doppler (heartbeat listening kit) to try to check the baby's heartbeat yourself. This is not a reliable way to check your baby's health. Even if you hear a heartbeat, this does not mean your baby is well." RCOG says the same.

Why it matters this much

Tommy's publishes the figure that explains the urgency: "In around half of stillbirths, the mother or birthing person noticed reduced fetal movements." It is careful with what that means — "Reduced fetal movements do not cause stillbirth but it is one of the signs that something is wrong" — and equally careful to add that noticing reduced movements does not mean an outcome is inevitable.

Now the reassurance: strong movements are not a warning

Tommy's addresses this directly: "Researchers have looked at what happens in a pregnancy after a mum or birthing person felt their baby moving more than usual but did not feel them move less or stop moving. These studies found that there was no link between feeling your baby moving more and having an unwell baby or a stillbirth."

It attaches one condition: "If your baby moves a lot and then stops moving at all, you should contact your maternity unit to get checked."

So a baby who is battering you is not a baby in distress. A baby whose pattern changes — in either direction, and particularly downwards — is a reason to ring.

Why kicks start to hurt

RCOG explains the trajectory: "The number of movements tends to increase until 32 weeks of pregnancy and then stay about the same, although the type of movement may change as you get nearer to your due date."

Several things change at once in the third trimester, and together they explain the pain:

The baby is bigger and stronger. The same kick has more force behind it.
There is less fluid to absorb it. Movements become less cushioned and more direct.
The movements themselves change. RCOG notes that the type of movement changes near term — less free kicking, more rolling, stretching and pushing, which produces sustained pressure rather than a jab.
Position. A foot lodged under a rib or a head pressing into the pelvis produces pain in a specific, recognisable spot.

RCOG describes what movements feel like generally as "a kick, flutter, swish or roll", and adds a detail that helps interpret quiet spells: "During both day and night, your baby has sleep periods that mostly last between 20 and 40 minutes, and are rarely longer than 90 minutes. Your baby will usually not move during these sleep periods." It also notes that "usually, afternoon and evening periods are times of peak activity."

Where it hurts, and why

Under the ribs. Classically a foot, classically on one side, and often relieved when the baby shifts. Rib pain that is severe, persistent and particularly on the right is a different symptom and belongs on the pre-eclampsia list.
Low in the pelvis and cervix. Sharp, brief and startling, more common once the head is engaged.
The bladder. Sudden pressure with an urgent need to pee.
The bowel and back passage. Uncomfortable pressure that people are often embarrassed to describe.

What helps

Nothing changes what your baby does, but the pain is partly about your position rather than theirs.

Change position. Leaning forward, on all fours, or standing up often gives a trapped limb somewhere else to go.
Sit upright rather than slumped. Slouching reduces the space under your ribs and makes a lodged foot worse.
Support the bump with a pillow when lying on your side, and one between the knees.
Stretch upwards. Raising your arms above your head opens the ribcage and often relieves rib pressure within seconds.

What not to do is try to make your baby move in order to check on them. Tommy's is direct: "No, you should not try to make your baby move. If you think your baby is moving less, their movements are less strong than usual or they have stopped moving, contact your midwife or maternity unit immediately." Cold drinks, sugary snacks and prodding the bump are not tests, and using them delays the call.

What counting does and does not involve

Both the NHS and RCOG have moved away from counting. RCOG: "There is not enough evidence to recommend the routine use of a movement chart. It is more important for you to be aware of your baby's individual pattern of movements throughout your pregnancy." The NHS: "There's no set number of movements you should feel each day — every baby is different. You do not need to count the number of kicks or movements you feel each day."

What replaces it is pattern recognition. Knowing when your baby is usually active, and what usual feels like, is what makes a change noticeable.

What happens if you ring

RCOG sets out the response by stage. Over 28 weeks, you will have a full antenatal check-up including your baby's heartbeat, and heart rate monitoring usually for at least 20 minutes. A scan may be arranged if your uterus measures smaller than expected, if there are risk factors, or if monitoring is normal but you still feel movements are reduced — normally performed within 24 hours.

It also says the thing people need to hear before dialling: "Most women who experience one episode of reduction in their baby's movements have a straightforward pregnancy and go on to have a healthy baby." And if it happens again: "You should never hesitate to contact your midwife or local maternity unit for advice, no matter how many times this happens."

Baby's Kicks Hurt in Late Pregnancy