Why hip pain becomes more common as pregnancy progresses
Nicola Tik
Hip pain is one of the more common experiences of the second and third trimesters, and it often catches people off guard. Understanding what is driving it can help you make sense of what your body is going through and what is likely to help.
From early pregnancy, the hormone relaxin works to loosen the ligaments across the pelvis and hips in preparation for birth. This is a necessary and normal process, but it does mean the joints in and around the hip have less of their usual passive stability. The muscles surrounding the hip, particularly the hip flexors at the front and the gluteal muscles at the side and back, take on more of the job of keeping the joint stable and controlled during movement.
At the same time, your growing bump shifts your centre of gravity forward. Your hips respond by adjusting the way they carry load, and this new demand on muscles that are already working harder than usual is one of the main reasons hip pain becomes more noticeable as pregnancy progresses.
Your hip flexors are the muscles that run from your lower spine and pelvis to the top of your thigh. They play a central role in how you walk, sit, and move between positions. During pregnancy, as the pelvis tilts forward in response to the growing bump, the hip flexors are held in a slightly shortened position for much of the day. Over time, this contributes to tension and discomfort at the front of the hip, which can sometimes radiate into the groin or upper thigh.
Prolonged sitting compounds this further. When you sit for long periods, the hip flexors remain shortened and the gluteal muscles, which help balance the load across the hip, are less active. This imbalance can make hip discomfort more pronounced, particularly when you stand up or start moving after a period of rest.
Hip pain during pregnancy is closely connected to what is happening in the pelvis more broadly. The sacroiliac joints, where the pelvis meets the base of the spine, are particularly affected by ligament loosening and increased load. Pain in this area is often felt deep in the buttock or at the side of the hip, and it can be difficult to distinguish from hip joint pain itself.
This is distinct from the lower back pain that comes from postural load on the lumbar spine, though the two can occur together. The key difference is where the discomfort is felt and what tends to aggravate it. Sacroiliac and pelvic girdle discomfort is often most noticeable during weight-bearing activities, turning over in bed, or moving from sitting to standing.
In the earlier months, hip discomfort tends to be mild and intermittent. By the third trimester, when the postural shift is most pronounced and the load through the hips and pelvis is at its greatest, symptoms often feel more persistent. Understanding what is driving this helps frame it as something to manage thoughtfully rather than push through.