Supports of the uterus
Supports of the uterus: ligaments, levels of support and their role in prolapse
The uterus is held up by a muscular floor below and by condensed endopelvic fascia (the cardinal and uterosacral ligaments) above; the broad and round ligaments are folds and cords that give little real support. Matching each support to the level it holds explains uterine, vault and vaginal wall prolapse and the operations that repair them.
True and false supports
| Type | Structures |
|---|---|
| Active (muscular) | Levator ani (pelvic diaphragm), perineal body, urogenital diaphragm |
| Passive (fascial ligaments) | Transverse cervical (cardinal, Mackenrodt), uterosacral, pubocervical |
| False (peritoneal or minor) | Broad ligament, round ligament, uterovesical and rectouterine folds |
- The pelvic diaphragm is the main support of the pelvic organs as a whole; the transverse cervical (cardinal) ligament is the main ligamentous support of the uterus.
- The ligaments are passive stabilisers. While the levator is healthy they carry little load; once it fails (childbirth damage) they take the strain and stretch over years, and prolapse follows.
The fascial ligaments
- Transverse cervical (cardinal) ligament: dense fascia from the side of the cervix and upper vagina to the lateral pelvic wall at the base of the broad ligament. It carries the uterine vessels, and the ureter passes through it 1.5–2 cm lateral to the cervix. In the Manchester (Fothergill) operation the elongated cervix is partly amputated and the cardinal ligaments are shortened and stitched in front of the stump.
- Uterosacral ligament: from the back of the cervix, beside the rectum, to the front of the sacrum. It pulls the cervix back and so keeps the uterus anteverted. It is felt on rectal examination and raises the rectouterine folds, the sides of the pouch of Douglas, where endometriotic nodules are found.
- Pubocervical fascia: from cervix forwards under the bladder to the pubis; weakness gives a cystocele.
Levels of vaginal support (DeLancey)
| Level | Structure | Holds | Failure |
|---|---|---|---|
| I | Cardinal–uterosacral complex | Cervix and vaginal apex | Uterine or vault prolapse, enterocele |
| II | Attachment to arcus tendineus fasciae pelvis | Mid-vagina | Cystocele, rectocele |
| III | Perineal body and fusion to levator ani | Lower third | Low rectocele, gaping introitus |
- At vaginal hysterectomy, the vault must be attached to the uterosacral and cardinal ligaments; if not, vault prolapse follows.
- Sacrospinous fixation: the vault is stitched to the sacrospinous ligament (ischial spine to sacrum and coccyx, with coccygeus), medial to the spine to avoid the pudendal nerve and vessels; buttock pain afterwards suggests nerve entrapment.
- A ring pessary rests on the levator ani and needs an intact perineal body; with a short torn perineum it falls out.
The false supports
- Broad ligament: a double fold of peritoneum from the uterus to the pelvic side wall, formed by the fused Müllerian ducts. Parts: mesosalpinx (next to the tube; paraovarian cysts and the epoophoron lie here), mesovarium (from its posterior layer, holding the ovary), mesometrium (beside the uterus). Contents include the tube, uterine and ovarian vessels, round ligament, ovarian ligament, ureter at its base.
- Round ligament of the uterus: from the cornu, below and in front of the tube, through the deep inguinal ring and inguinal canal to the labium majus. It holds the fundus forward (anteversion) but gives almost no protection against prolapse. It is the only uterine ligament with an extrapelvic course, and the main content of the female inguinal canal (with the ilioinguinal nerve). Lymph from the cornu follows it to the superficial inguinal nodes. Stretching in the second trimester gives sharp brief groin pain on movement.
- Ligament of the ovary: ovary to cornu. With the round ligament it is a gubernaculum remnant.
- Suspensory (infundibulopelvic) ligament: peritoneal fold from the ovary over the brim carrying the ovarian vessels; the ureter lies close behind, so it must be seen before clamping. It is not a gubernacular remnant.
Uterine prolapse
- Degrees: first, cervix descends within the vagina; second, cervix to the introitus; third (procidentia), the uterus lies outside the introitus.
- Causes: stretching of the cardinal–uterosacral complex and levator damage at delivery (multiparity, prolonged second stage); menopause (loss of oestrogen-supported collagen unmasks old damage); chronic cough, constipation, obesity. In a nulliparous woman look for collagen disorders (Ehlers–Danlos, Marfan) or denervation (spina bifida).
- Complications: decubitus ulcer on the most dependent part of the cervix from venous congestion and friction (biopsy if it does not heal); cervical elongation and keratinisation; bilateral hydroureteronephrosis when the ureters are dragged down and kinked at the hiatus, reversing after reduction; residual urine and infection.
Remember True supports are the levator ani and the cardinal–uterosacral complex; the broad and round ligaments are only position holders.
Exam trap The broad ligament is peritoneum, not a support; shortening the round ligaments does not cure prolapse.
Exam trap The uterosacral ligament is the one felt on rectal examination; the sacrospinous ligament lies nearby but is not attached to the cervix.
Test yourself on this topic
5 of the 17 questions in our bank on this topic. Choose an answer to see why every option is right or wrong.
A 58-year-old para 4 whose last delivery was 20 years ago first notices a vaginal bulge 6 years after menopause. She has never had hormone therapy. Which change most explains why the prolapse appeared after menopause?
Answer: Loss of oestrogen-supported collagen
Childbirth stretches the cardinal and uterosacral ligaments and can denervate the levator ani, but symptoms often appear years later. The endopelvic fascia and ligaments contain oestrogen receptors, and after menopause collagen content and strength fall, the vaginal walls thin and muscle mass declines. This unmasks the earlier damage, so prolapse is common in postmenopausal women. Age-related loss of muscle bulk adds to it.
Why prolapse appears late
- Childbirth stretches ligaments
- Levator ani denervation
- Menopause: less collagen
- Old damage unmasked
Remember Delivery damages, menopause reveals.
Exam trap Prolapse in a nulliparous young woman points to a collagen or nerve disorder, not menopause.
Why the other options are wrong
- Regeneration of the pudendal nerve Nerve recovery would improve, not worsen, support.
- Hypertrophy of the round ligaments The round ligaments atrophy and give little support anyway.
- Rise in progesterone softening fascia Progesterone falls after menopause; relaxation is a pregnancy effect.
- Ossification of the sacrospinous ligament Ligament calcification does not cause prolapse.
During an abdominal hysterectomy, a student sees a cord running from the uterine cornu, below and in front of the tube, to the deep inguinal ring. The surgeon remarks that it helps hold the fundus forward but gives almost no protection against prolapse. Which structure is it?
Answer: Round ligament of the uterus
The round ligament runs from the uterine cornu, just below and in front of the uterine tube, through the broad ligament to the deep inguinal ring, along the inguinal canal and into the labium majus. It is a remnant of the lower gubernaculum and contains smooth muscle. It tilts the fundus forwards, helping anteversion, but it is too long and lax to resist descent of the uterus. The real supports are the cardinal and uterosacral ligaments and the levator ani.
Round ligament
- Cornu to labium majus
- Through the inguinal canal
- Holds fundus forward
- No real support against prolapse
Remember Round ligament: in front of and below the tube.
Exam trap Shortening the round ligaments does not cure prolapse.
Why the other options are wrong
- Ligament of the ovary Runs from the cornu to the ovary, behind the tube, not to the inguinal ring.
- Suspensory ligament of the ovary Runs from the ovary to the pelvic brim and carries the ovarian vessels.
- Uterosacral ligament Passes back to the sacrum.
- Lateral cervical ligament The main support of the cervix, running to the side wall.
At laparoscopy, a 4 cm thin-walled cyst is found between the right uterine tube and the right ovary, both of which are separate from it. In which part of the broad ligament does it lie?
Answer: Mesosalpinx
The broad ligament has three parts. The mesosalpinx is the part between the uterine tube and the attachment of the mesovarium; the mesovarium attaches the ovary to the back of the broad ligament; and the mesometrium is the larger part below, beside the uterus. Paraovarian (paratubal) cysts lie in the mesosalpinx and arise from mesonephric or paramesonephric remnants such as the epoophoron. They are separate from the ovary, which helps distinguish them from ovarian cysts.
Parts of the broad ligament
- Mesosalpinx: next to the tube
- Mesovarium: holds the ovary
- Mesometrium: beside the uterus
- Paraovarian cysts in the mesosalpinx
Remember Cyst separate from tube and ovary: think mesosalpinx.
Exam trap A paraovarian cyst is not an ovarian cyst; the ovary is seen separately.
Why the other options are wrong
- Mesovarium Attaches the ovary itself; a cyst here would sit on the ovarian hilum.
- Mesometrium Lies beside the uterus, below the ovary and tube.
- Suspensory ligament of ovary Runs from the ovary to the pelvic brim with the ovarian vessels.
- Ligament of the ovary A cord joining the ovary to the uterus, not a fold.
A 24-year-old nulliparous woman has a second-degree uterine prolapse. She has hypermobile joints, very stretchy skin and wide papery scars on her knees. What is the most likely underlying cause of the prolapse?
Answer: Defective collagen in the pelvic fascia
Prolapse in a young nulliparous woman suggests an intrinsic weakness of the supporting tissues. Joint hypermobility, hyperextensible skin and wide atrophic scars point to Ehlers–Danlos syndrome, a disorder of collagen structure or processing. The cardinal and uterosacral ligaments and endopelvic fascia rely on collagen for strength, so they stretch easily. Marfan syndrome and spina bifida (neurogenic weakness of the pelvic floor) are other causes in this age group.
Prolapse in the young
- Nulliparous: look for intrinsic weakness
- Ehlers–Danlos: stretchy skin, lax joints
- Marfan syndrome
- Spina bifida: denervated floor
Remember Young, no babies, prolapse: check collagen and nerves.
Exam trap Ask about joint and skin laxity in any nulliparous woman with prolapse.
Why the other options are wrong
- Denervation of the levator ani at birth She has never given birth.
- Congenital absence of the round ligaments Absence of the round ligaments would not cause prolapse.
- Excess oestrogen softening the ligaments Oestrogen strengthens rather than weakens pelvic collagen.
- Chronic raised intra-abdominal pressure Nothing in the history suggests chronic cough or constipation.
Three years after a vaginal hysterectomy for uterine prolapse, a 63-year-old woman has a bulge of the vaginal vault reaching the introitus. The operation note records that the vault was closed without suturing the paracervical ligaments to it. Which level of vaginal support was left unrepaired?
Answer: Level I: cardinal–uterosacral complex
The vagina is supported at three levels. Level I is the cardinal–uterosacral complex, which suspends the cervix and upper vagina from the pelvic side wall and sacrum; failure gives uterine or vault prolapse. Level II attaches the mid-vagina laterally to the arcus tendineus fasciae pelvis, and its loss gives cystocele and rectocele. Level III is fusion of the lower vagina with the perineal body, perineal membrane and levator ani. At hysterectomy the uterosacral and cardinal ligaments are attached to the vault to restore level I support.
Levels of vaginal support
- Level I: cardinal–uterosacral (apex)
- Level II: arcus tendineus (mid-vagina)
- Level III: perineal body (lower third)
- Vault prolapse = level I failure
Remember Attach the uterosacral ligaments to the vault at hysterectomy.
Exam trap The round and broad ligaments are not true supports of the uterus or vault.
Why the other options are wrong
- Level II: paracolpium to arcus tendineus Loss gives anterior and posterior wall bulges, not vault descent.
- Level III: perineal body and membrane Loss gives perineal descent and a gaping introitus.
- Round ligaments to the inguinal canal Round ligaments give almost no support against prolapse.
- Broad ligaments to the pelvic side wall The broad ligament is a peritoneal fold, not a support.
Where this sits in the CPSP syllabus
- Obstetrics & Gynaecology, Paper 2: Pelvis, pelvic floor and perineum, Supports of the uterus: ligaments and their role in prolapse