By the third trimester the uterus has run out of room. It presses the ribs from below. The rib cage itself spreads. A kick lands on the same sore spot, over and over. That is the ordinary version. It is miserable, and it is common. It is not the low groin jab of round ligament pain, and it is not the whole belly going tight.
What rib pain in pregnancy feels like
Most people describe a sore, bruised ache just under the ribs, on one side or both. It can be sharp for a second when the baby stretches, then settle into a dull pain. Sitting makes it worse, because the belly folds up into the ribs. Standing, or leaning forward over a chair, often gives a little space.
A tight bra, a long car ride, and lying flat all press the same spot. The pain should not stop you breathing. If every breath stabs, that is not “just the baby.”
Right rib or left rib
The right side gets mentioned more. The uterus often tilts that way, and the liver sits under the right ribs, so there is less give. A kick under the right ribs is a very usual complaint in the last two months.
Left rib pain happens too. The baby’s position decides it. Left-sided pain that is only an ache, and that changes when the baby moves, is still the same problem. Do not ignore left-sided pain that comes with chest pressure, a racing heart, or breath you cannot catch. That needs a same-day call, not a stretch.
How to sleep with rib pain
Flat on your back is the worst position late in pregnancy, for the ribs and for everything else. Lie on your side, with a pillow between the knees and another under the belly so the weight is not hanging on the lower ribs. Some people do better half-sitting, propped on two pillows, so the uterus drops forward instead of up.
If the right side is the sore one, try the left for a while. If the left is sore, try the right. Turn slowly. A sudden roll is what sets off a round ligament jab in the groin, which is a separate pain lower down.
What eases it in the day
Loosen the bra, or switch to a softer band that does not sit on the sore rib. Every hour, stand and lift both arms overhead for a few breaths. That opens the cage. A warm shower on the back is fine. A very hot bath is not. Short walks hurt less than a long sit.
Do not take ibuprofen, or any painkiller, unless your own doctor or midwife has said it is safe in your trimester. A support belt worn high can make rib pain worse. Belts are for the low pelvis, not for this.
If the whole belly goes hard and then soft, that is a tightening, not a rib bruise. How those feel, and when they are labour, is in what Braxton Hicks feel like.
When it is not just the baby
| Usual rib pain | Get it checked | |
|---|---|---|
| Feel | Ache under the ribs, worse sitting | Stabbing pain, or pain on every breath |
| What changes it | Standing, stretching, the baby shifting | Comes after fatty meals, with vomiting |
| With it | Kicks. You can still talk and walk | Headache, spots in your vision, sudden swelling |
| Breathing | Tight, but air still goes in | You cannot catch your breath |
Right-sided pain under the ribs, plus a bad headache or swelling in the face and hands, can be a blood-pressure problem. Pain under the right ribs after greasy food, with nausea, can be the gallbladder. Both are common enough in pregnancy that guessing is a bad plan.
When to call a doctor
- Pain with headache, vision changes, or sudden swelling
- Pain that stops you taking a full breath, or chest pain
- Fever, vomiting, or pain that follows meals
- Regular tightenings with the rib pain, if you are under 37 weeks
- The baby moving less than usual
Bottom line: Rib pain in pregnancy is usually the uterus crowding the ribs, worse when you sit, easier on your side at night. Pain with headache, vomiting, or breath you cannot catch is not a stretch-it-out problem.
This article is for information only. It is not medical advice. If rib pain is severe, or it comes with headache, swelling, fever, or trouble breathing, call your doctor, midwife, or emergency care.
