What causes uterine prolapse?
Uterine prolapse happens when the muscles, ligaments, and connective tissue that hold the uterus and upper vagina in place lose their strength, and the uterus drops toward the vaginal opening. It is a support problem, closer to a hernia than to a disease.
In almost everyone, more than one thing wears that support down over the years. Childbirth and aging are the big ones, but they rarely act alone.
The support that gives way
A set of ligaments suspends the cervix and upper vagina from above, and a sheet of connective tissue and muscle holds everything from below. When the ligaments stretch or tear and the connective tissue thins, the uterus has nothing to keep it up.
That connective tissue is mostly collagen. Women with prolapse tend to have less total collagen and to break it down and rebuild it faster, so the tissue is weaker to begin with. This is part of why prolapse can run in families and why it sometimes shows up in women who never gave birth.
Humans are built with two disadvantages here. Standing upright puts more of the load on connective tissue rather than muscle, and the pelvic floor has to stretch enough to let a baby’s head pass through it. Both of those work against the pelvic floor long before any single risk factor is added.
Childbirth
Childbirth is the single biggest risk factor. In a study that examined first-time mothers 6 to 12 months after delivery, about 1 in 3 (31%) already had at least mild loss of pelvic support.
How you deliver matters, though not as much as people expect. In that same group, 14 to 15% of women who delivered vaginally had the prolapse reach or pass the vaginal opening, compared with about 5% after a cesarean without labor. A cesarean lowers the risk but does not erase it, so pregnancy itself, not only the delivery, plays a role.
Each additional vaginal birth adds strain. So do a larger baby and an assisted delivery with forceps, which is linked to a higher chance of prolapse later. The damage is often silent for years: nerves and muscles injured during birth can slowly weaken and stretch, and the prolapse itself may not appear until decades afterward.
Aging and menopause
Prolapse becomes more common with age. As you get older, the pelvic floor loses muscle faster than it loses connective tissue, so it leans on the weaker of the two.
Menopause adds to this. Estrogen helps maintain collagen and tissue elasticity, and as it falls, pelvic support weakens further. Menopause is a genuine risk factor, but it usually works alongside childbirth and aging rather than causing prolapse by itself.
Pressure in the belly
Anything that repeatedly raises pressure inside the abdomen pushes down on the same support that is already thinning.
Chronic constipation and straining on the toilet are the clearest example, and they are worth treating for this reason alone. Extra body weight adds steady downward pressure, and a long-standing cough does the same with every episode. Constipation and weight are two of the few risk factors you can actually change.
Family history and connective tissue
Some of the risk is built into your tissue. The collagen changes seen in prolapse turn up even in women who never gave birth, which suggests some people are simply more prone to it. Loose, hypermobile joints tend to travel with this, and inherited connective tissue disorders raise the risk as well. A family history of prolapse is a reasonable thing to mention when we talk.
How I think about this
Most women I see have several of these factors at once rather than one clear cause. You cannot undo childbirth, your genes, or your age.
But having risk factors is not the same as having prolapse. Many women with several risk factors never develop it, and even when mild prolapse is present, it often stays put. In one review, 78% of women with untreated symptomatic prolapse had no change over 16 months.
What I focus on is what we can change. Treating constipation, keeping a healthy weight, and managing a chronic cough all take pressure off the pelvic floor, and pelvic floor physical therapy can help you use the muscle you still have.
When to get checked
It is worth an evaluation if you notice:
- A bulge or a feeling of pressure or heaviness in the vagina
- A sense that something is falling out, or that you have to push tissue back to empty your bladder or bowels
- New changes in how your bladder or bowels work
- Several risk factors and a wish to understand your own risk
Diagnosing prolapse takes a history and a pelvic exam, not a scan. Finding it early gives us the widest set of options, from watchful waiting to a pessary to surgery, and the right choice depends on how much it bothers you.
References
- Hilton P, Dolan LM. Pathophysiology of urinary incontinence and pelvic organ prolapse. BJOG: an International Journal of Obstetrics and Gynaecology. 2004. doi:10.1111/j.1471-0528.2004.00505.x
- Handa VL, Nygaard I, Kenton K, et al. Pelvic organ support among primiparous women in the first year after childbirth. International Urogynecology Journal. 2009. doi:10.1007/s00192-009-0937-3
- Barber MD. Pelvic organ prolapse. BMJ. 2016. doi:10.1136/bmj.i3853
- Committee on Practice Bulletins—Gynecology, American Urogynecologic Society. Pelvic Organ Prolapse (Practice Bulletin No. 214). Obstetrics & Gynecology. 2019.