Where Is Your Pelvis Located on a Female?

The female pelvis is a basin-shaped bony structure located at the very base of the trunk, roughly between your navel and the tops of your thighs. It sits below the lumbar spine and above the legs, forming the transition zone where your torso meets your lower body. If you place your hands on the bony ridges you can feel at your hips and then imagine those bones curving inward and meeting at the front just above your pubic area, you are tracing the outer edges of the pelvis. But the pelvis is far more than bone: it houses a complex arrangement of organs, muscles, and nerves that differ meaningfully from the male pelvis in both shape and function.

The Bones That Make Up the Pelvis

The bony pelvis is a ring. It is formed by three fused bones on each side, known collectively as the hip bone: the ilium (the wide, flaring bone you feel at your hip), the ischium (the bone you sit on), and the pubis (the bone at the front of the pelvis). These three bones fuse together during adolescence into a single structure on each side. At the front, the left and right pubic bones meet at a joint called the pubic symphysis. At the back, each hip bone connects to the sacrum, a triangular bone at the base of the spine, forming the sacroiliac joints. Hanging below the sacrum is the coccyx, or tailbone. Together, this ring of bone creates a bowl that protects the organs inside and transmits the weight of the upper body down through the legs.

When people say “pelvis,” they sometimes mean only the bones. Other times they mean the entire region, including everything inside the bony ring. In medicine, “pelvic” typically refers to the whole cavity and its contents. For most practical purposes, when a doctor asks where your pelvic pain is, they are asking about the area enclosed by or near this bony ring, from roughly the level of your belly button down to your perineum.

What Is Inside the Female Pelvis

The space enclosed by the pelvic bones is called the pelvic cavity. In women, this cavity contains the bladder (at the front), the uterus and cervix (in the middle), the vagina (below the uterus), and the rectum (at the back). The ovaries and fallopian tubes also sit within the pelvic cavity, tucked on either side of the uterus. These organs are packed closely together, which is why problems in one organ can sometimes cause symptoms that feel like they originate in another.

A modeling study using MRI-based 3D reconstruction illustrated just how tightly these structures relate to each other, mapping four major cavity spaces: the uterine cavity surrounded by the muscular wall, the upper vaginal canal partly enclosed by the cervix, the bladder with its open urethral end, and the rectal cavity. The resulting model showed how these organs sit in an assembly where each structure’s position directly affects its neighbors.¹ That adjacency explains a lot about why, for example, a growing uterus during pregnancy presses on the bladder, or why severe constipation can cause a sensation of pressure in the vaginal area.

The Pelvic Floor and Its Role

The bottom of the pelvic cavity is not open. A sheet of muscles and connective tissue called the pelvic floor stretches across the base of the pelvis like a hammock, supporting the organs above it. These muscles serve two main purposes: they act as a floor that holds up the abdominal and pelvic organs, and they function as a constricting mechanism around the urethral, anal, and vaginal openings to maintain continence.²

Not all pelvic floor muscles do the same job. Research into the architecture of these muscles has shown that individual muscles within the pelvic floor have different designs suited to different tasks. Some have short fibers that make them good at stabilization, holding things steady. Others have longer fibers built for larger movements and excursion.³ This specialization matters practically: when someone does pelvic floor exercises, they are training a group of muscles that each contribute something different to the overall function of support and control.

The pelvic floor also supports the urethra. The “hammock hypothesis” in urology describes how the tissue underneath the urethra acts like a supportive platform: when abdominal pressure increases (during a cough or sneeze, for instance), a well-supported urethra gets compressed against this firm backing and stays closed.⁴ When that support weakens, stress urinary incontinence can result.

The Nerve Network You Cannot See

Running through the pelvis is a network of autonomic nerves that controls bladder function, bowel function, and sexual sensation. In female cadaver studies, the superior hypogastric plexus was found embedded in connective tissue in the presacral space (the area just in front of the sacrum), sitting just below the peritoneum, the membrane that lines the abdominal cavity. Below that, each side has a hypogastric nerve that descends to form a larger collection of nerve fibers called the inferior hypogastric plexus, which receives contributions from the sacral spinal nerves.⁵

These nerves are described in relation to surgical landmarks like the sacral promontory, the ureters, and the uterine blood vessels because surgeons operating in the pelvis need to know exactly where they are to avoid damaging them.⁶ Injury to these nerve pathways during hysterectomy, colorectal surgery, or other pelvic procedures can lead to bladder dysfunction, bowel problems, or changes in sexual function. The density and complexity of this nerve network is one reason pelvic surgery requires such precise anatomical knowledge.

How the Female Pelvis Differs from the Male

The female pelvis is wider and shallower than the male pelvis, with a broader pelvic inlet (the opening at the top of the pelvic cavity) and a wider subpubic angle (the angle formed where the two pubic bones meet at the front). These differences exist primarily because the female pelvis must accommodate childbirth. The pelvic outlet is also larger in women. If you compared a female and male pelvis side by side, the female one would look more like a wide, shallow bowl, while the male one would appear taller and narrower, more like a funnel.

Interestingly, some pelvic measurements do not differ between the sexes. A CT-based study comparing pelvic parameters in healthy men and women found no significant difference in pelvic incidence, anatomical pelvic tilt, or anatomical sacral slope between men and women.⁷ These parameters describe how the pelvis is oriented relative to the spine and the hip joints rather than how wide or deep the pelvis is. So the differences that matter most for obstetric purposes are about width and shape, not about spinal alignment.

This sexual dimorphism is not fully present from birth. Research on pelvic development has shown that the bony pelvis becomes distinctly different between the sexes around puberty, with female-typical widening occurring in response to hormonal changes. The pelvis continues to change subtly into adulthood.⁸

Not All Female Pelvises Have the Same Shape

Even among women, pelvis shape varies considerably. The classic classification system, developed by Caldwell and Moloy, divides female pelvises into four types based on the shape of the pelvic inlet: gynecoid (round), android (heart-shaped, more typical of males), anthropoid (oval, longer front to back), and platypelloid (flat, wider side to side). The gynecoid shape is considered the most favorable for vaginal delivery because it provides the most room for the baby’s head to pass through.

How common each type is depends on the population studied, but the gynecoid shape is consistently the most frequent. One CT-based survey found that about 52% of pelvises were gynecoid, 20% platypelloid, 15% anthropoid, and 13% android.⁹ Another study using 3D CT in multiparous women reported the gynecoid type at roughly 50%, consistent with long-standing estimates from obstetric textbooks.¹⁰ The practical takeaway is that nearly half of women have a pelvis that does not match the textbook “ideal” shape, and most still deliver vaginally without complications. Pelvic shape is one factor among many, including the size of the baby and the flexibility of the pelvic joints during labor.

What Happens to the Pelvis During Pregnancy

Pregnancy transforms the pelvis temporarily. Hormones, primarily estrogen, progesterone, and relaxin, increase the laxity of the joints and ligaments throughout the body, and the pelvic joints are particularly affected. This increased flexibility allows the pubic symphysis and sacroiliac joints to loosen and widen, creating more room for the baby to pass through during delivery.¹¹

This loosening is functional, but it comes with side effects. Pregnancy-related pelvic girdle pain is a musculoskeletal condition that causes persistent pain at the front or back of the pelvic ring, sometimes radiating across the hip joint and into the thigh. Symptoms can begin as early as the first trimester, during labor, or even in the postpartum period.¹² Many women experience this as a deep ache at the front of the pelvis (over the pubic symphysis), at the back near the sacroiliac joints, or both. It can make walking, rolling over in bed, or climbing stairs painful. The condition is common enough that it has its own diagnostic criteria and treatment protocols, yet it is still underrecognized. Many women are told that pelvic pain during pregnancy is “just normal,” which delays appropriate management.

Chronic Pelvic Pain Outside of Pregnancy

Pain in the pelvic region is not exclusive to pregnancy. Chronic pelvic pain, defined as pain in the pelvic girdle region lasting over six months, can arise from the gynecologic, urologic, gastrointestinal, or musculoskeletal systems.¹³ This is one of the most challenging pain syndromes to diagnose precisely because so many structures are packed into such a small space. Pain originating from a uterine condition like endometriosis, from the bladder in interstitial cystitis, from the bowel in irritable bowel syndrome, or from the muscles and joints of the pelvic floor can all feel remarkably similar.

When the cause turns out to be musculoskeletal, clinicians try to narrow down whether the primary pain generator is in the lumbosacral area, the coccyx, the sacroiliac joint, the pelvic floor muscles, the groin, or the lower abdominal region. Where you feel pelvic pain can give clues about the source, but referral patterns (where pain travels away from its origin) make this tricky. Pain from the sacroiliac joint, for instance, can refer into the buttock, groin, or down the leg, mimicking sciatica. Pelvic floor muscle spasm can cause deep, aching pain that patients sometimes describe as feeling like it is in the vagina, the rectum, or both at once.

How the Pelvis Changes with Age

The pelvis does not stay the same throughout a woman’s life. An MRI study of 120 asymptomatic women aged 15 to 74 found progressive age-related changes in several pelvic parameters. The pubic symphysis inclination angle increased with age, reaching an average of about 52 degrees in women aged 65 to 74, compared with roughly 41 degrees in the youngest group. The space in front of the bladder expanded significantly in women over 45 compared with younger women. The gap between the rectum, vagina, and the levator muscles also widened in the oldest group.¹⁴ These changes suggest a gradual loosening and widening of the pelvic structures with age, which helps explain why pelvic organ prolapse becomes more common in older women.

Pelvic organ prolapse, where one or more of the pelvic organs descend from their normal position, is one of the most common age-related conditions affecting the female pelvis. It has been studied for a possible link to osteoporosis, since both conditions involve changes in collagen and connective tissue. One study of 554 postmenopausal women found that lumbar spine bone density appeared to correlate inversely with prolapse severity. However, after adjusting for age, time since menopause, weight, and vaginal delivery history, the association disappeared.¹⁵ In other words, both conditions increase with age, but one does not seem to directly cause the other once you account for shared risk factors.

Why the Female Pelvis Is Shaped the Way It Is

The shape of the female pelvis has been the subject of evolutionary debate for decades. The traditional explanation, proposed by Washburn in 1960 and known as the “obstetrical dilemma,” suggested that the human pelvis is a compromise between the demands of walking upright (which favors a narrow pelvis) and the demands of giving birth to large-brained babies (which favors a wide one). However, more recent biomechanical research has undercut this idea. Studies of walking efficiency suggest that pelvic width does not substantially affect how efficiently a person walks.¹⁶

So if a wider pelvis would not actually make walking harder, why hasn’t evolution simply produced wider birth canals? One alternative explanation focuses on pelvic floor stability: a larger birth canal would increase the risk of pelvic organ prolapse and incontinence.¹⁷ Another factor is that a narrower pelvis provides better support for the weight of the internal organs and the fetus during the long human gestation period. The trade-off, in this newer view, is not between walking and birth but between giving birth easily and keeping everything supported during the months of pregnancy that precede it.¹⁶ The science here is still evolving, but the shift away from the classic walking-versus-birth story is significant because it changes how researchers think about obstructed labor and why human childbirth is so difficult compared with other mammals.

How Doctors Visualize the Pelvis

When clinicians need to see what is happening inside the pelvis, MRI is often the preferred imaging tool for gynecologic questions. It provides excellent soft-tissue contrast, meaning it can distinguish between the uterus, the bladder wall, a fibroid, or a mass much more clearly than a standard X-ray or CT scan. High-resolution images taken in multiple planes allow clinicians to evaluate the anatomy in fine detail.¹⁸ Ultrasound is used more commonly as a first-line tool for many gynecologic concerns because it is inexpensive, widely available, and does not involve radiation. CT scans are faster and better for evaluating bone and acute emergencies, while MRI excels at characterizing soft-tissue conditions like endometriosis, adenomyosis, fibroids, and pelvic floor disorders. If you are told you need a pelvic MRI, it usually means your doctor wants a closer, more detailed look than ultrasound can provide.

The pelvis, then, is far more than just “hips.” It is a bony ring with complex joints, a cavity full of organs packed close together, a muscular floor doing several jobs at once, and a nerve network that controls some of the body’s most essential functions. Its location, at the crossroads between the spine and the legs, the abdominal cavity and the outside world, makes it central to movement, reproduction, and daily comfort in ways most people do not think about until something goes wrong.