Unstable lieUnstable lie: It is a condition where the presentation of the fetus is constantly changing even after the 36th week of pregnancy, when it should have stabilised.
Causes of unstable lie:
- Grand multipara with lack of uterine tone and pendulous abdomen
- Contracted pelvis
- Placenta praevia (i.e., placenta is in the lower segment)
- Pelvic tumour.
- Patient is admitted at 37 weeks.
- Elective cesarean section is done in most cases.
- External cephalic version followed by stabilising induction can be tried if there is no contraindication to ECV.
Stem Cells and Therapies In Gynecology
Reproductive tissues are the important source of stem cells (progenitor cells). Stem cells have the potential to be used in the field of regenerative medicine.
Potentials for the Use of Stem Cells in Regenerative Medicine
- Treatment of inherited genetic disorders.
- Treatment of hematological diseases.
A stem cell has the ability to renew (reproduce) itself for long periods.
Properties of Stem Cells
- Ability to self-renew (undergoing numerous cell divisions) maintaining the undifferentiated state.
- Multipotency: Capacity to differentiate into a mature cell type.
Totipotent Stem Cells are produced by first few divisions of the fertilized egg cell. Totipotent stem cells (from the morula) can differentiate into embryonic and extraembryonic cell types. Totipotent cells can produce a complete and viable organism.
Pleuripotent Stem Cells are descendent of totipotent cells. These cells can differentiate on tissues derived from any of the three germ layers including fetal tissues (placenta, umbilical cord, amnion, amniotic fluid cells).
Embryonic Stell Cells are pluripotent. These cells are derived from the inner cell mass of a blastocyst.
Multipotent Stem Cells can differentiate into various tissues originating from a single germ layer (mesenchymal cells or hemopoietic stem cells that produce red blood cells, white blood cells, platelets).
Unipotent cells produce only their own cell type. They have greater self-renewal property than fully mature cells.
Theoretically, the more primitive or 'potent' stem cells are, the potential for uncontrolled cell division is more strong. Unfortunately the potential for oncogenesis is also high. It is the major concern about the oncogenic potential of pleuripotent stell cells (embryonic stem cells). Nonpleuripotent cells source are not inherently oncogenic.
Embryonic Stem (ES) Cells have the potentials to be used in regenerative medicine.
Multipotent Stem Cells can be obtained from several fetal tissues (following medical termination of pregnancy or at birth).
Use Of Embryonic Stem (Es) Cells In Regenerative Medicine
Regeneration of urogenital tract tissues
Treatment of stress urinary incontinence (SUI) Currently SUI is treated by mechanical support to the bladder (TOT) (See p. 404) Biomaterials (autologous stem or urethral tract progenitor cells) are injected into the utethral phincter. This is aimed to restore and regenerate rhabdomyosphincter muscle content and function. These autologous cells commonly integrate into the sphincter complex. These cells then differentiate and ultimately lead to sphincter regeneration. This ongoing research might be of immense benefits in regenerative medicine.
- Acellular natural or synthetic biomaterials are used as an implant which becomes incorporated through ingrowth of cells from the adjacent native host cells of the bladder. The biomaterials used are: Small intestinal submucosa and bladder-derived acellular matrix.
- Implantation of scaffolds (cell-seeded collagen- coated PGA scaffolds) pre-incubated with autologous cells wrapped in omentum within a vascular bed). Reports are available indicating possibility of creating full thickness bladder wall.
Biomaterials can be used for the use of pelvic organ prolapse (POP) and urinary incontinence. The purpose is to generate new muscles/tissues which can perform in an integrated manner with the existing tissues to provide mechanical support to the pelvic organs. Currently synthetic meshes are used for POP and SUI. Mesh erosion, infection are the known complications.
Hybrid biomaterials (synthetic and naturally-derived polymers) may be fabricated to restore pelvic floor function and cure of SUI. Biomaterials should have good biocompatibility and appropriate biomechanical and biochemical properties.
Mullerian ducts reconstruction
- Progenitor cells with ability of self-repair (bone marrow stem cells) can be used for uterine mal formations.
- Autologous cells (from vaginal biopsy) can be expanded and functional vagina can be reconstructed for a woman with vaginal agenesis.
However, till date it is essential to understand its known limitations, putative benefits and the unknown risks. Until there is sufficient evidence on the efficacy of therapy, each case should be considered on an individual basis.