Symphysis pubis dysfunction (SPD) is a condition where the joint at the front of your pelvis becomes overly loose and unstable, causing pain that can range from mild discomfort to severe difficulty walking. It occurs most often during pregnancy, when hormonal changes soften the ligaments holding the two pubic bones together. The joint normally has a gap of about 4 to 5 millimeters, but during pregnancy that gap can widen to 7 mm or more. When the separation exceeds 1 centimeter, it’s considered pathological and can lead to significant pain, instability, and trouble with everyday movements.
Why Pregnancy Makes the Joint Unstable
The pubic symphysis is a narrow, cartilage-filled joint connecting the left and right halves of your pelvis. It’s designed to be nearly rigid, but pregnancy changes that. A hormone called relaxin, produced mainly by the ovaries, works throughout pregnancy to loosen ligaments across the pelvis. This loosening is intentional: it allows the pelvis to widen slightly so a baby can pass through during delivery. Relaxin levels are highest during the first trimester and again near the end of pregnancy, which is when symptoms tend to peak.
The problem is that relaxin doesn’t target just one ligament. It breaks down the fibrous tissue that holds joints together by suppressing the proteins that build and maintain connective tissue, while ramping up enzymes that degrade it. In some women, this process goes too far. The ligaments around the pubic symphysis become so lax that the joint shifts with normal movement, producing pain and a grinding or clicking sensation. Adding the weight of a growing baby to an already unstable joint makes things worse, and the forces of labor can push the separation further still.
Relaxin levels typically drop about four weeks after delivery, which is why most cases of SPD begin to resolve on their own postpartum. But until those ligaments firm back up, the joint remains vulnerable.
Who Is Most at Risk
SPD can happen in any pregnancy, but certain factors make it more likely. Women who have had multiple pregnancies (multiparity), a history of back or pelvic injury, or joint hypermobility are at higher risk. Carrying a larger-than-average baby, having a high body weight, or delivering past your due date also increases the chance. Other documented risk factors include a family history of pelvic pain, a history of chronic low back pain, high stress levels, early onset of menstruation, and a lack of regular exercise before pregnancy.
If you had SPD in a previous pregnancy, it’s more likely to recur and may appear earlier in subsequent pregnancies.
What SPD Feels Like
The hallmark of SPD is a steady, deep pain centered at the front of the pelvis, right over the pubic bone. It commonly radiates into the lower abdomen, groin, inner thighs, perineum, and lower back. Some women describe it as a dull ache; others feel sharp, stabbing pain with certain movements. You might also notice a clicking or grinding sensation in the joint when you walk or shift positions.
Specific movements tend to make the pain noticeably worse:
- Walking, especially for longer distances
- Climbing stairs
- Standing on one leg, such as when getting dressed
- Getting in and out of a car
- Rising from a chair
- Spreading your legs apart, including rolling over in bed
- Twisting or turning your body
The pain often worsens as the day goes on and can be especially bad at night when you shift positions in bed. For some women, SPD is a mild annoyance. For others, it can become severe enough to require crutches or a wheelchair by the third trimester.
How SPD Is Diagnosed
Diagnosis is primarily based on your symptoms and a physical exam. Your provider will press on the pubic bone and surrounding areas to locate tenderness, and may ask you to perform specific movements to reproduce the pain. One common test involves standing on one leg for up to 30 seconds while the examiner watches whether your pelvis stays level or drops on the opposite side, which can indicate instability and muscle weakness around the hip and pelvis.
Imaging is not always necessary but can confirm the diagnosis and rule out other causes. On a standard X-ray or ultrasound, a pubic symphysis gap wider than 1 cm during pregnancy points to a pathological separation (called diastasis). If the gap exceeds 4 cm, which is rare, an MRI may be ordered to check for damage to the cartilage and surrounding ligaments. A residual separation greater than 2.5 cm after delivery is associated with chronic pain during movement and intercourse.
Managing Pain During Pregnancy
There is no way to reverse the hormonal loosening while you’re still pregnant, so management focuses on stabilizing the joint and avoiding movements that provoke pain. A pelvic support belt worn low across the hips can compress the joint and reduce shifting. Many women find this provides immediate, noticeable relief.
Physical therapy is the most effective treatment during pregnancy. A pelvic floor physiotherapist can teach you exercises that strengthen the muscles supporting the pelvis, particularly the deep stabilizers of the core and pelvic floor, without putting stress on the symphysis. They can also help you modify how you move through your day.
Small changes in daily habits make a real difference. When getting out of bed, roll onto your side and keep your knees together as you swing your legs over the edge, rather than twisting. Climb stairs one step at a time, leading with your stronger leg going up and your weaker leg going down. When getting into a car, sit down first and then swing both legs in together rather than stepping in one foot at a time. Avoid standing on one leg for any reason, and keep your knees together or close together when rolling over in bed. Sleeping with a pillow between your knees helps keep the pelvis aligned and reduces nighttime pain.
Ice applied to the pubic area can help after a particularly painful day. If your provider approves pain relief, that conversation is worth having early, since untreated pain can lead to compensatory movement patterns that create new problems in the hips and lower back.
Labor and Delivery With SPD
Having SPD does not mean you need a cesarean delivery, but it does require some planning. The key concern during labor is avoiding positions that force the legs wide apart, since this pulls directly on the already-unstable joint. Talk with your birth team beforehand about keeping leg spreading to a minimum during exams and delivery. Side-lying positions, hands-and-knees, and supported kneeling are generally more comfortable than lying on your back with legs in stirrups.
If you’re using an epidural, be especially careful. Numbness can mask pain signals from the joint, so you or your birth partner should watch that your legs aren’t spread wider than is comfortable for you when you’re not medicated. Some women find it helpful to measure their pain-free range of leg separation before labor and communicate that limit to their care team.
Recovery After Delivery
Most women see significant improvement within the first few weeks after giving birth, as relaxin levels drop and the ligaments begin to tighten again. The joint gap, which widens to about 7 mm by the end of pregnancy, gradually returns to its pre-pregnancy measurement. For many women, pain resolves fully within a few months.
Recovery is not always linear, though. Breastfeeding can maintain slightly elevated relaxin levels, and the physical demands of caring for a newborn (lifting, carrying, bending) can keep the joint irritated. Continuing pelvic floor physiotherapy postpartum helps rebuild the stability that was lost during pregnancy and speeds the return to normal activity.
In a small number of cases, SPD symptoms persist for six months or longer. A residual gap of more than 2.5 cm is associated with ongoing pain, particularly during movement and sexual activity. Women with persistent symptoms may benefit from more intensive rehabilitation, and in very rare, severe cases where the joint fails to stabilize, surgical intervention may be considered.
SPD Outside of Pregnancy
Though pregnancy is far and away the most common cause, SPD can also occur after pelvic trauma, such as a car accident or a fall. It occasionally develops in athletes who place repetitive stress on the pelvis, particularly runners and soccer players. The underlying mechanism is the same: the ligaments holding the pubic symphysis together are damaged or stretched beyond their ability to stabilize the joint. Treatment in non-pregnancy cases follows similar principles of stabilization, physical therapy, and activity modification, though the hormonal component is absent and recovery timelines may differ.