Stem Cells in Clinical Trials for Pelvic Floor Disorders — Plain‑Language Summary and What It Means for Stem Cell Banking and Regenerative Medicine

Pelvic floor disorders (PFDs) — such as stress urinary incontinence (SUI), anal (fecal) incontinence, and pelvic organ prolapse — result from weakness or injury to muscles, nerves, or connective tissues of the pelvic floor. Traditional treatments (rehabilitation, surgery) often give incomplete relief. Stem cell (SC) therapy is being tested as a regenerative alternative.

This review looked at human clinical trials up to November 7, 2020. Eleven prospective clinical trials met the criteria: seven for stress urinary incontinence (total ~99 patients) and four for anal/ fecal incontinence (total ~66 patients). No clinical trials of stem cells for prolapse repair were found. Different types of stem cells were used (adipose-derived, muscle-derived, cord blood, mesenchymal), with variable cell numbers and delivery routes. Short-term safety appeared acceptable — most adverse events were mild and related to the tissue harvest site. However, results for effectiveness were mixed and inconsistent between studies. Because studies were small and very different in design, cell type, dose, delivery, and outcome measures, it was not possible to combine results. Larger, standardized randomized trials are needed before we can say whether stem cell therapy should be adopted for PFDs.

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Pelvic floor disorders (PFDs) happen when the muscles, connective tissue, or nerves that support the pelvis become weak or damaged—often after childbirth or injury. The most common are:

• Stress urinary incontinence (SUI): leaking with coughing, sneezing, or exercise.
• Anal (fecal) incontinence: loss of bowel control.
• Pelvic organ prolapse: organs sagging into the vaginal canal.

These conditions reduce quality of life and social functioning. Current treatments—pelvic floor exercises, pessaries, or surgery—help many people but are not always fully effective and can carry risks.

Why stem cells? In simple terms:

• Stem cells can turn into different cell types (muscle, connective tissue) or support repair by releasing growth factors.
• They may strengthen damaged muscle or nerve tissue and stimulate the body’s own repair mechanisms (a mix of direct replacement and “helpful signals” called paracrine effects).
• Sources include a patient’s own fat (adipose tissue), skeletal muscle, bone marrow, or donated cord blood. Using a person’s own cells (autologous) reduces immune rejection.

Animal studies showed promising repair of sphincter muscles (urinary and anal), which led to early human trials.

Relevance to stem cell banking: preserving cord blood or other cell sources when people are younger may provide higher-quality cells for future regenerative therapies. Cryopreserving cells can be important if autologous cell therapies become standard.

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• The authors searched major medical databases (PubMed, Scopus, Cochrane, Web of Science) up to Nov 7, 2020 for human clinical trials using cultured/characterized stem cells for PFDs.
• They excluded animal/preclinical studies, reviews, letters, and studies that did not actually isolate or grow stem cells.
• Two reviewers screened studies, extracted key data (study design, cell source, number of patients, outcomes, adverse events), and summarized the results.
• The protocol was registered (PROSPERO CRD42020216551).

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Overall:

• 11 prospective clinical studies met inclusion criteria.
• 7 studies targeted stress urinary incontinence (SUI) — total ~99 patients.
• 4 studies targeted anal (fecal) incontinence — total ~66 patients (including 10 men).
• No clinical trials were found testing stem cells for pelvic organ prolapse repair.

Types of stem cells and how they were used:

• Adipose-derived stem cells (from fat) — used in several SUI and fecal incontinence trials.
• Muscle-derived stem cells (from skeletal muscle) — used in many trials aiming to repair sphincter muscles.
• Human cord blood stem cells — used in one SUI study.
• Expanded mesenchymal stem cells (a common lab‑grown SC type) — used in some trials.

Delivery methods:

• For urinary sphincter: transurethral (through the urethra), periurethral (around the urethra) injections (via skin or vaginal approach).
• For anal sphincter: direct injection into external or internal sphincter, sometimes at time of surgical repair (sphincteroplasty).

Cell numbers injected:

• Wide range: roughly 1.8 × 10^6 up to 5 × 10^7 for urinary trials; 6 × 10^6 up to 10^8 cells in anal trials. Muscle-derived batches tended to be larger.

Safety results (short term):

• No severe procedure-related adverse events in the included trials.
• Reported minor problems:
• Hematomas at the tissue harvest site (a few cases)
• Short-lived dysuria (painful urination) after injection (a few cases)
• Urinary tract infections (a couple of cases)
• One study reported erythema at a surgical site
• Two patients withdrew because of pain during the procedure in one trial
• Overall: injection procedures appeared safe in the short follow-up reported, but sample sizes were small.

Efficacy results — mixed and inconsistent:

• Stress urinary incontinence (7 studies, 99 patients):
• Several small single-arm studies reported improvements in subjective measures (patient-reported symptoms and quality of life) and some objective measures (pad tests, cough stress tests) in a subset of patients.
• Examples:
• Adipose-derived cell trials: modest or inconsistent improvements.
• Muscle-derived cell trials and one cord blood trial: some reported higher patient satisfaction and improvements in measures like pad weight or negative cough test in portions of patients.
• Some studies showed improvements that faded over time (recurrence in some responders).
• Urodynamic measures (e.g., maximal urethral closing pressure, MUCP) varied across studies — some showed gains in specific subgroups, others did not.
• Anal (fecal) incontinence (4 studies, 66 patients):
• Two randomized controlled trials (RCTs) compared SC injection versus placebo/saline and did not find clear significant benefits on objective measures in one trial and showed only small changes in another.
• Single-arm studies of muscle-derived cells reported encouraging subjective and some objective improvements (reduced incontinence episodes, better quality-of-life scores, improved manometry and EMG in some reports), but these studies lacked control groups.
• Imaging (endoanal ultrasound) generally showed minimal or inconsistent structural changes.
• Electromyography (EMG) sometimes showed increased electrical activity after cell injection in single-arm studies.

Why the mixed results?

• Trials were small and very different in:
• Which patients were included (cause of incontinence, severity)
• Source and type of stem cells
• Number of cells injected
• How and where cells were injected
• Outcome measures and follow-up timing
• This heterogeneity prevented pooling data or making strong conclusions.

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Key points

• Short-term safety: Across the small trials reviewed, stem cell injections for SUI and anal incontinence appear to be reasonably safe in the short term, with mainly mild, expected harvest- or procedure‑related issues.
• Efficacy: Evidence of benefit is mixed. Some small single-arm studies (particularly with muscle-derived cells) report meaningful symptom improvement for some patients. However, randomized controlled trials—especially for fecal incontinence—have not consistently shown clear advantages of stem cell injections versus placebo.
• No trials for pelvic organ prolapse repair were available among the clinical human studies reviewed.

Why this matters for regenerative medicine and stem cell banking

• Cell source matters: Muscle-derived cells sometimes showed more promising functional outcomes in sphincter repair than adipose-derived cells in these trials. Different stem cell sources have different capabilities: some are more likely to become muscle, others may act mainly by releasing growth factors (paracrine effects).
• Timing and cell quality: Younger cells (for example, cord blood cells) and cells banked earlier in life may maintain higher regenerative potential. This supports the concept behind cord blood and other cell banking: preserving higher-quality autologous cells for future therapies could be advantageous.
• Standardization needed: Before stem cell treatments become routine, we need standardized protocols for:
• Which cell type to use (adipose, muscle, cord blood, mesenchymal)
• How many cells to give (dose)
• How to deliver them
• How to measure success (consistent objective and subjective outcomes)
• Cost and logistics: Harvesting, expanding, and delivering cultured cells are complex and expensive. Harvest procedures (e.g., liposuction or muscle biopsy) carry their own risks and morbidity. Banking cells in advance could avoid repeat harvesting and may reduce delays.

Research gaps and next steps

• Larger randomized controlled trials are required with:
• Well-defined patient groups (e.g., intrinsic sphincter deficiency vs. hypermobility)
• Standardized cell processing and dosing
• Blinded outcome assessment and longer follow-up (to address durability)
• Comparative trials testing different cell sources head-to-head would help identify the most effective approach.
• Studies should include standardized safety monitoring and report long-term outcomes (including potential aberrant differentiation, though this was not observed in the small trials).
• Mechanistic studies to clarify whether cells act by replacing damaged tissue or primarily by paracrine stimulation will inform optimal cell selection and preparation.

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• Early clinical trials suggest that injecting cultured stem cells for stress urinary incontinence and fecal incontinence is feasible and appears safe in the short term.
• Evidence for clear, reliable benefit is not yet established—results vary across small, heterogeneous studies.
• No clinical trials for prolapse repair using stem cells were identified in this review.
• For people considering stem cell banking, these findings underline the potential future value of having autologous, well‑preserved cells (e.g., cord blood banking or other cell preservation) should effective regenerative therapies become available. However, definitive therapies and standardized treatment paths are still under development.
• Larger, standardized randomized trials are needed to determine whether stem cell therapy should become a routine option for pelvic floor disorders.

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(These are the key clinical studies included or discussed in the systematic review.)

• Arjmand B, Safavi M, Heidari R, Aghayan H, Bazargani ST, Dehghani S, et al. Concomitant transurethral and transvaginal‑periurethral injection of autologous adipose derived stem cells for treatment of female stress urinary incontinence: a phase one clinical trial. Acta Med Iran. 2017;55(6):368–74.

• Carr LK, Steele D, Steele S, Wagner D, Pruchnic R, Jankowski R, et al. 1‑year follow‑up of autologous muscle‑derived stem cell injection pilot study to treat stress urinary incontinence. Int Urogynecol J. 2008;19(6):881–3. https://doi.org/10.1007/s00192-007-0553-z

• Garcia‑Arranz M, Alonso‑Gregorio S, Fontana‑Portella P, Bravo E, Diez Sebastian J, Fernandez‑Santos ME, et al. Two phase I/II clinical trials for the treatment of urinary incontinence with autologous mesenchymal stem cells. Stem Cells Transl Med. 2020. https://doi.org/10.1002/sctm.19-0431

• Kuismanen K, Sartoneva B, Haimi S, Mannerström B, Tomás E, Miettinen S, et al. Autologous adipose stem cells in treatment of female stress urinary incontinence: results of a pilot study. Stem Cells Transl Med. 2014;3(8):936–41. https://doi.org/10.5966/sctm.2013-0197

• Lee CN, Jang JB, Kim JY, Koh C, Baek JY, Lee KJ. Human cord blood stem cell therapy for treatment of stress urinary incontinence. J Korean Med Sci. 2010;25(6):813–6. https://doi.org/10.3346/jkms.2010.25.6.813

• Sharifiaghdas F, Tajalli F, Taheri M, Naji M, Moghadasali R, Aghdami N, et al. Effect of autologous muscle‑derived cells in the treatment of urinary incontinence in female patients with intrinsic sphincter deficiency and epispadias: a prospective study. Int J Urol. 2016;23(7):581–6. https://doi.org/10.1111/iju.13097

• Sharifiaghdas F, Zohrabi F, Moghadasali R, Shekarchian S, Jaroughi N, Bolurieh T, et al. Autologous muscle‑derived cell injection for treatment of female stress urinary incontinence: a single‑arm clinical trial with 24‑months follow‑up. Urology Journal. 2019;16(5):482–7. https://doi.org/10.22037/uj.v0i0.4736

• de la Portilla F, Guerrero JL, Maestre MV, Leyva L, Mera S, García‑Olmo D, et al. Treatment of faecal incontinence with autologous expanded mesenchymal stem cells: results of a pilot study. Colorectal Dis. 2020. https://doi.org/10.1111/codi.15382

• Frudinger A, Marksteiner R, Pfeifer J, Margreiter E, Paede J, Thurner M. Skeletal muscle‑derived cell implantation for the treatment of sphincter‑related faecal incontinence. Stem Cell Res Ther. 2018;9(1):233. https://doi.org/10.1186/s13287-018-0978-y

• Romaniszyn M, Rozwadowska N, Malcher A, Kolanowski T, Walega P, Kurpisz M. Implantation of autologous muscle‑derived stem cells in treatment of fecal incontinence: results of an experimental pilot study. Tech Coloproctol. 2015;19(11):685–97. https://doi.org/10.1007/s10151-015-1373-7

• Sarveazad A, Newstead GL, Mirzaei R, Joghataei MT, Bakhtiari M, Babahajian A, et al. A new method for treating fecal incontinence by implanting stem cells derived from human adipose tissue: preliminary findings of a randomized double‑blind clinical trial. Stem Cell Res Ther. 2017;8(1):40. https://doi.org/10.1186/s13287-017-0489-2

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• Stem cells: Cells that can become different types of tissue or support repair by secreting helpful signals.
• Autologous: Cells taken from the same person who will receive them.
• Mesenchymal stem cells (MSCs): A common lab‑grown cell type from bone marrow, fat, or other tissues; thought to help by both differentiating and secreting growth factors.
• Paracrine effects: Actions where cells release molecules (growth factors, cytokines) that tell nearby cells to grow, survive, or repair themselves.
• Cryopreservation / Banking: Freezing cells (cord blood, tissue) so they remain usable later; younger/better-preserved cells may have stronger regenerative potential.

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• This review shows early clinical work but not definitive proof that stem cell injections will become standard treatment for pelvic floor disorders.
• If you are considering cell banking (like cord blood banking), one potential benefit is having access to younger, autologous cells that may be more effective for future regenerative therapies. However, the clinical usefulness of stored cells for PFDs specifically has not been proven yet.
• Decisions about banking should consider current evidence, costs, and that future therapies and regulatory standards are still evolving.

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• Palmieri S, Cola A, Ceccherelli A, et al. Italian validation of the German Pelvic Floor Questionnaire for pregnant and postpartum women. Eur J Obstet Gynecol Reprod Biol. 2020;248:133–6. https://doi.org/10.1016/j.ejogrb.2020.03.032

• Fibbe WE. Mesenchymal stem cells. A potential source for skeletal repair. Ann Rheum Dis. 2002;61(Suppl 2):ii29‑31. https://doi.org/10.1136/ard.61.suppl_2.ii29

• Fitzwater JL, Grande KB, Sailors JL, Acevedo JF, Word RA, Wai CY. Effect of myogenic stem cells on the integrity and histomorphology of repaired transected external anal sphincter. Int Urogynecol J. 2015;26(2):251–6. https://doi.org/10.1007/s00192-014-2496-5

• Schmid FA, Williams JK, Kessler TM, et al. Treatment of stress urinary incontinence with muscle stem cells and stem cell components: chances, challenges and future prospects. Int J Mol Sci. 2021;22(8):3981. https://doi.org/10.3390/ijms22083981

• Plair A, Bennington J, Williams JK, et al. Regenerative medicine for anal incontinence: a review of regenerative therapies beyond cells. Int Urogynecol J. 2021;32(9):2337–47. https://doi.org/10.1007/s00192-020-04620-x

(Clinical trial references listed above: 16–26.)

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If you’d like, I can:

• Summarize individual trials in a simple table (study design, cell type, number of patients, main outcome).
• Explain differences between adipose‑derived, muscle‑derived, and cord blood stem cells and what those differences mean for banking choices.