Pelvic Girdle Pain in the Third Trimester: What Physiotherapy Can Do

Pelvic girdle pain is the most common musculoskeletal complaint of pregnancy, and it is most common in the third trimester when the load is highest and the connective tissue most relaxed. Most people are told it is normal and to wait for delivery. That advice is not wrong about the normal part. It is incomplete about the waiting part.

This article explains what pelvic girdle pain in the third trimester is, why it tends to peak in the final weeks, and what physiotherapy actually does about it.

What pelvic girdle pain is

Pelvic girdle pain (PGP) is a term that covers pain in and around the joints of the pelvis during or after pregnancy. The pelvis has three joints: the two sacroiliac joints at the back, where the pelvis meets the sacrum, and the symphysis pubis at the front. PGP can involve one or all three, in different combinations.

Symphysis pubis dysfunction (SPD) is the name for the front-pain pattern: sharp or aching pain at the pubic bone, typically worse with stairs, rolling over in bed, dressing, or any activity that requires one leg to bear weight while the other lifts. Sacroiliac joint pain presents at the back of the pelvis, one or both sides, sometimes travelling into the buttock or upper thigh.

Both are PGP. The assessment sorts out which pattern is present and which treatment emphasis fits.

Population studies put the prevalence of PGP in pregnancy somewhere between 45 and 86 percent, depending on how strictly the condition is defined. A systematic review in the European Spine Journal found that about 20 percent of pregnant people develop significant, activity-limiting PGP. It is not rare, and it is not a minor complaint.

Why it gets worse in the third trimester

Three things come together in the third trimester that make pelvic girdle pain more likely and more severe.

First, the weight distribution shifts. The uterus and baby are heaviest in the final eight to ten weeks, and all of that sits directly over the pelvic joints. More load means more force through joints that are already under stress.

Second, relaxin continues to peak. Relaxin is the hormone that loosens pelvic ligaments to allow the pelvis to expand for delivery. It does not target only the pelvis: it circulates systemically and affects all the connective tissue in the body. Looser ligaments mean the joints rely more heavily on muscle control for stability. When those muscles are fatigued or weak, the joints become symptomatic.

Third, the gait changes. A wider stance, a waddling walk, more single-leg loading as balance shifts: all of these place asymmetrical demands on pelvic joints that are already working harder than usual.

The result is that someone who was managing fine at 24 weeks can find themselves limited at 30 and struggling at 35.

What the assessment looks for

The physiotherapy assessment for third-trimester PGP has a specific structure. The clinician asks about the location, timing, and triggers of the pain. Tasks that load one leg at a time, walking up stairs, standing from a chair, getting in and out of a car, are particularly informative because they reveal whether the sacroiliac joints or the symphysis pubis are driving the picture.

The posterior pelvic pain provocation test (P4 test) is a reliable clinical test for sacroiliac joint involvement. The active straight leg raise test identifies how well the pelvis is loaded through the abdominal and pelvic muscles. Neither test requires the pregnant person to lie face down.

The assessment also includes a brief movement screen and a look at what daily activities are currently most affected. This shapes the management priorities for the session.

What physiotherapy does

Treatment for third-trimester PGP is not passive. The goal is to change what is driving the pain, not just manage it.

Load management comes first. This means identifying which specific tasks are most provocative and adjusting how they are done. Sitting to stand from a lower chair, sitting to dress rather than standing, reducing stair trips, and using a support surface for single-leg tasks: these changes reduce the daily load on symptomatic joints without requiring the person to stop living their life.

Targeted strengthening addresses the muscle control problem. The hip abductors and external rotators, the deep hip flexors, and the pelvic floor all contribute to how well the pelvis is stabilised during single-leg tasks. Weakness in any of these groups is common in the third trimester, partly from reduced activity and partly from the changed movement patterns that pain creates. The exercise program is specifically designed for the trimester, the symptom pattern, and whatever capacity is currently available.

Manual therapy has a role when the joints are mechanically restricted or when soft tissue tension is a significant driver. Sacroiliac joint mobilisation and soft tissue work to the gluteal and hip external rotator muscles can provide meaningful pain relief in specific presentations. The manual therapy used during pregnancy is adapted to avoid sustained positions that create pressure on the vena cava.

Support belts are useful in a subset of presentations, particularly when pain is severe during walking or weight-bearing. A belt worn across the sacroiliac joints or the symphysis pubis region can offload the joints during peak load periods. The physiotherapist can fit and trial the belt at the session, assess whether it helps, and advise on how and when to use it. Not every case needs one, and wearing one without knowing whether it is useful is a reasonable thing to establish in clinic rather than guessing.

Pelvic floor coordination becomes part of the picture when the pelvic floor is contributing to the load pattern. The pelvic floor works alongside the deep abdominal and hip muscles to stabilise the pelvis. Where there is PGP, there is often a disruption in how those muscles coordinate. Pelvic floor training in this context is less about strength and more about the timing and control of the contraction.

What physiotherapy cannot change

Relaxin is a hormone, not a mechanical problem. Physiotherapy cannot reduce relaxin levels or make the ligaments tighter. What it can do is build the muscle support around joints that are currently under-stabilised. The analogy is tightening the muscles around a loose joint: you are not fixing the loose joint, you are making the muscles work harder to compensate for it.

Similarly, the weight of the baby and uterus cannot be reduced. Load management strategies change how that weight is transferred through the joints, but the load itself is not going anywhere until delivery.

Pain that is completely provoked by hormonal changes and has no mechanical component may improve less with physiotherapy than presentations that have a meaningful muscular or loading driver.

Does this resolve after delivery?

For most people, pelvic girdle pain improves significantly in the weeks after delivery, as relaxin levels fall and the load reduces. For some it persists into the postpartum period, particularly if the delivery involved prolonged pushing, an instrumental delivery, or if the muscle control gaps were not addressed before delivery.

The risk factor for persistent postpartum PGP is significant pre-delivery pain combined with no rehabilitation during pregnancy. Getting started before delivery is not just about comfort in the third trimester. It is also about the position you are starting from when recovery begins.

When to book

A reasonable time to book is when PGP begins to affect daily activity. Waiting until delivery is not a management plan. Physio for PGP can start at any point in pregnancy, including the third trimester.

If you have already had PGP in a previous pregnancy, an early assessment in the current pregnancy allows a programme to be established before the third-trimester peak. If this is a first pregnancy and symptoms started recently, start now.

Pelvic health physiotherapy is available at all five of our Metro Vancouver studios: Lougheed, Coquitlam, Richmond, New Westminster, and North Burnaby.

Frequently asked questions

Is pelvic girdle pain the same as sciatica?

No. Sciatica refers to pain from irritation of the sciatic nerve, usually involving the lower back and travelling down the leg to the foot. PGP is joint and muscle pain in and around the pelvis, not nerve pain. They can coexist, and the assessment differentiates them.

Will a support belt fix pelvic girdle pain?

A support belt can reduce pain during weight-bearing activities for some people. It does not address the muscle control gaps that are contributing to the problem, so it works better as a short-term aid alongside physiotherapy than as a standalone solution.

Can I keep exercising with pelvic girdle pain?

Often yes, with modifications. The principle is to avoid single-leg loading when it is significantly provocative. Pool walking, seated cycling, and specific strengthening exercises are often well-tolerated. A physiotherapist can advise on which activities to continue and which to modify for your specific presentation.

Is PGP worse in subsequent pregnancies?

Research does suggest that a history of PGP in a previous pregnancy is a risk factor for it occurring earlier or more severely in the next one. This makes early assessment and prevention work useful if you are in a second or later pregnancy.

What is the difference between PGP and normal pregnancy discomfort?

Normal discomfort is general, dull, and not specifically provoked by single-leg loading tasks. PGP tends to be sharp, has a specific location, and is clearly provoked by particular movements. The distinction is worth establishing with a physiotherapist, because the management is different.

This article is general information, not personal medical advice. A physiotherapist can assess whether the patterns described apply to your specific situation.

Sources

• European Spine Journal: Pelvic Girdle Pain and Low Back Pain in Pregnancy
• CHCPBC: College of Health and Care Professionals of BC
• Birth-prep physiotherapy in BC: what happens in a third-trimester pelvic floor session
• Prenatal physiotherapy: what it is and when to start