The sentence that decides this page

The NHS puts both halves of the answer in one paragraph, and it is worth reading twice: "Pain just under the ribs is common in later pregnancy due to the growing baby and uterus pushing up under the ribs. But if this pain is bad or persistent, particularly on the right side, it can be a sign of pre-eclampsia."

So rib pain is genuinely ordinary. And the same location, with different qualities, is one of the symptoms that maternity services want to hear about immediately. The rest of this page is about telling them apart.

What ordinary rib pain feels like

The mechanical version arrives in the third trimester, when there is simply nowhere left for your uterus to expand except upwards. It typically:

Feels like pressure, aching or bruising along the lower edge of the ribcage rather than deep inside.
Is worse when you sit slumped, and eases when you stand up straight or stretch upwards.
Changes when the baby moves — a foot lodged under a rib is a recognisable and specific discomfort.
Is often on one side because of how the baby is lying, and can swap sides.
Eases in the last weeks if the baby's head engages and drops lower.
Comes and goes rather than sitting there constantly.

Heartburn can also be felt high and centrally and get described as rib pain, particularly at night after a big meal.

The version that needs a call

Pre-eclampsia rib pain is different in four ways: it is more severe, it does not let up, it is classically under the right ribs, and it usually brings company.

The NHS lists it among the symptoms that need an immediate call to your midwife, GP or labour ward, alongside:

A sudden increase in swelling in your face, hands or feet.
A very bad headache.
Problems with your vision, such as blurring or flashing lights.
Heartburn that does not go away when you take antacid medicine.
Feeling very unwell.
Feeling sick and being sick.

The HSE frames the same cluster from the headache end: contact your midwife, GP or obstetrician immediately if you have "a severe headache — especially with other symptoms including blurred vision, upper stomach pain, nausea or swelling". "Upper stomach pain" and "pain under the ribs" are the same symptom described from two directions.

ACOG lists pain in the upper right abdomen among the warning signs of preeclampsia, and RCOG's patient information includes severe pain just below the ribs in the symptoms that should prompt urgent contact.

Why right-sided matters

Because the liver sits under the right ribs, and pre-eclampsia can affect it. That is the whole reason the side is specified in national guidance. Left-sided rib ache after a long day at a desk is a different animal from right-sided pain that woke you up and has not shifted.

The one thing not to do

Do not take an antacid, feel no better, and conclude that it must be bad indigestion. The NHS specifically lists "heartburn that does not go away when you take antacid medicine" as a pre-eclampsia symptom. Heartburn that is not responding to treatment is on the call list, not off it.

Equally, do not wait for high blood pressure to make the decision for you. Pre-eclampsia usually starts after 20 weeks or just after the birth, and the NHS notes that in the early stages there are often no symptoms at all — which is why it is picked up on routine blood pressure and urine checks. Symptoms arriving before anyone has recorded a high reading is not reassurance.

Other things that cause rib pain

Musculoskeletal strain. The joints where ribs meet the breastbone and spine take load as posture changes. This is usually reproducible by pressing on the spot, and worse with certain movements.
Gallbladder problems, which also sit on the right under the ribs and are more common in pregnancy. Pain after fatty meals, sometimes going through to the back or shoulder blade, is worth reporting.
Referred pain from labour. The NHS's back pain advice lists "pain in one or more of your sides (under your ribs)" as a reason to contact your GP or midwife urgently — because flank pain can indicate a kidney infection.
Anything with breathlessness or chest pain attached. That combination belongs to the emergency list, not this one.

What helps ordinary rib pain

National guidance offers no rib-specific treatment, so what follows is general and low-risk rather than evidence-backed:

Sit upright with your lower back supported rather than slumping, which shortens the space your ribs have.
Stretch upwards — raising the arm on the painful side above your head can give the ribcage room.
Change position. Leaning forward over a birth ball or onto a table often relieves it within seconds.
Check your bra fits. Underwiring sitting on an already-compressed ribcage makes it worse.
Smaller meals, if heartburn is part of the picture.

If pain is stopping you sleeping or getting through the day, tell your midwife. There may be a referral to physiotherapy available, and it is a reasonable thing to ask for.

When to call someone

Your midwife, GP or labour ward immediately if rib pain is severe or persistent, especially on the right, or comes with headache, vision changes, sudden swelling, unrelieved heartburn, nausea and vomiting, or feeling generally very unwell (NHS).
Your GP or midwife urgently if rib or flank pain comes with fever, pain when you pee, or bleeding (NHS).
Your local emergency number — 999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand — if rib or chest pain comes with breathlessness, coughing up blood, or collapse.
Your maternity unit for rib pain you simply cannot place, at any hour. The HSE's advice applies: "Always trust your instincts."

The short version

A bump pushing your ribs upwards hurts, and that is most rib pain in the third trimester. The pain that does not fit — severe, constant, right-sided, or travelling with a headache, blurred vision, sudden swelling or unrelieved heartburn — is on the pre-eclampsia list and gets phoned in the same day.

Rib Pain in Pregnancy