Three problems, one description

"My hip hurts" covers at least three separate things in pregnancy, and they have different triggers, different treatments and different levels of urgency. Sorting out which one you have is most of the work.

Deep in the front, over the pubic bone or into the groin

This is pregnancy-related pelvic girdle pain. The NHS describes it as pain felt "over the pubic bone at the front in the centre, roughly level with your hips", "across 1 or both sides of your lower back", "in the area between your vagina and anus (perineum)" and "spreading to your thighs". Some people "feel or hear a clicking or grinding in the pelvic area".

The triggers are the giveaway. The NHS lists pain that is worse when walking, going up or down stairs, standing on one leg — for example while getting dressed — turning over in bed, and moving your legs apart, such as getting out of a car. If your pain is provoked by exactly those movements, this is what you have.

It is common. The NHS estimates pelvic girdle pain "affects up to 1 in 5 pregnant women to some degree", and states plainly that it "is not harmful to your baby". The HSE describes the same condition, and the NHS points readers to RCOG's patient information on pelvic girdle pain for a fuller account of assessment and treatment.

Sharp, brief, low down on one side when you move suddenly

The NHS lists ligament pain among the harmless causes of stomach pain in pregnancy, describing it as pain that "can feel like a sharp cramp on one side of your lower tummy" as the ligaments stretch to support your growing bump. It fires when you stand up quickly, roll over, cough or sneeze, and it is over in seconds.

The distinguishing feature is duration. Ligament pain is a stab. Pelvic girdle pain is an ache that builds through a day of walking.

The outside of one hip, worst at night in bed

Soreness on the bony point of the hip you have been lying on, worse after a night on that side and eased by changing position or adding a pillow, is soft tissue taking load rather than a joint problem. There is no national guidance naming it, and none needed — it responds to how you set your bed up.

What to do about pelvic girdle pain

This is the one with a pathway, which is why it is worth naming to your midwife rather than describing vaguely as hip pain.

NICE's antenatal care guideline is short and specific: "For women with pregnancy-related pelvic girdle pain, consider referral to physiotherapy services for exercise advice and/or a non-rigid lumbopelvic belt."

The NHS adds what that physiotherapy involves: exercises to strengthen the pelvic floor, stomach, back and hip muscles, and equipment if needed, such as crutches or pelvic support belts. It also makes a point about timing: "Getting diagnosed as early as possible can help keep pain to a minimum and avoid long-term discomfort."

It is equally honest about the ceiling: "These problems tend not to get completely better until the baby is born, but treatment from an experienced practitioner can improve the symptoms during pregnancy." Physiotherapy manages this condition; it does not cure it before birth.

Day-to-day measures from NHS guidance

Keep active, but avoid the things that make it worse.
Wear supportive shoes.
Put equal weight on each leg when standing.
Sit down to get dressed and undressed.
Put a pillow between your legs in bed.
Keep your knees together getting in and out of the car.
Avoid sitting or standing for long periods, going up and down stairs too often, and lifting heavy objects.

The NHS also notes something people rarely think to ask about: a physiotherapist "should be able to provide advice on coping with the emotional impact of living with chronic pain". If the pain is causing you real distress, that is a reason to tell your GP or midwife, not to tough it out.

What it means for birth

The NHS states that "most women with PGP can have a vaginal birth", and suggests writing it into your birth plan so everyone supporting you knows. Thinking in advance about which positions are comfortable, and how far apart your legs can go without pain, is more useful than deciding in the moment. Being in water can take weight off the joints and make moving easier.

The version that is not musculoskeletal

One-sided pain in the groin, thigh or calf that comes with swelling, warmth or redness is not a joint problem. The HSE lists the symptoms of deep vein thrombosis as "pain, swelling or tenderness in 1 leg — usually in your calf area", "warm or red skin over the affected area", "a heavy ache in the affected area" and "pain in your calf that gets worse when you bend your foot up towards your knee", and notes "they usually only happen in 1 leg".

Clots can also form in the pelvic veins, where pain in the groin, buttock or lower tummy on one side may be the only symptom. Pregnancy raises the risk, and the risk continues for six weeks after birth. If one-sided groin or leg pain is new, constant, and not tied to a movement, phone rather than stretch.

When to call someone

Your midwife or GP if pelvic pain makes it hard to move around, hurts getting out of a car or turning over in bed, or is painful on stairs — the NHS lists these as the signs of pelvic girdle pain, and they warrant a physiotherapy referral.
Your midwife, GP or maternity unit urgently if one leg has pain, swelling, tenderness, warmth or redness, or a heavy ache (HSE).
Your local emergency number — 999 in the UK and Ireland, 911 in the US and Canada, 000 in Australia, 111 in New Zealand — if leg or groin pain comes with chest pain, sudden breathlessness, pain on breathing in, or coughing up blood.
Your maternity unit if hip or groin pain comes with fever, bleeding, fluid loss, regular tightenings, or pain when you pee.
Your GP or midwife if pain is causing you considerable distress. The NHS says explicitly that you may need additional treatment.

The short version

Groin and pubic pain provoked by walking, stairs, turning in bed and parting your legs is pelvic girdle pain, and NICE says to consider referral to physiotherapy for exercise advice and a non-rigid belt. Brief stabs when you move suddenly are ligament pain. Soreness on the outside of the hip is usually your mattress. One-sided pain with swelling is a different question entirely.

Hip and Groin Pain in Pregnancy