Thesis (PhD)--Stellenbosch Uni versity, 2000. / ENGLISH ABSTRACT: Intracytoplasmic sperm injection (ICSI) introduced a revolutionary way of treatment for male
factor infertility. With the exception of some cases of non-obstructive azoospermia, all other
male factor infertility cases have the potential to be successfully treated with ICS!. The only
prerequisite seems to be the presence of a motile or viable immotile sperm cell for each oocyte.
In this study we report on our own experience with the development and implementation of the
ICSI method in the Reproductive Biology Unit at Tygerberg Hospita!. An analysis of 5 years of
ICSI experience showed that semen parameters, sperm morphology, motility and concentration
did not influence fertilization and pregnancy rates adversely. In most cases, patients who could
not be treated with in vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT), due to poor
semen parameters or fertilization failure, were treated successfully with ICS!. Even a case of
globozoospermia was treated successfully with ICS!.
Testicular spermatozoa, fresh or frozen-thawed, also resulted in excellent fertilization and
pregnancy rates. Cryopreservation of testicular samples facilitated the management of the
infertile couple, aiding the coordination of the recovery of vital gametes from both partners and
also limiting the repetition of testicular biopsies. Incubation (maturation) of testicular spermatozoa
also induced an enhancement in pregnancy rates.
It can be concluded that ICSI proved to be a treatment method with success similar to that of in
vitro fertilization (IVF) and gamete intrafallopian transfer (GIFT), in spite of a severe male factor.
The study also indicated transfer route and embryo quality (viability) to be very important factors
in the success of ICS!. The tubal transfer route was shown to be a significant contributor to the
pregnancy success (compared to uterine transfer) as was the transfer of embryos that showed
early division to the 2-cell stage, 26 hours post injection. The transfer of early dividing embryos
into the fallopian tube resulted in a pregnancy rate of almost 40%, a result similar to that of GIFT
with a mild male factor.
The role of the oocyte in fertilization and pregnancy success was also revealed indirectly by the
introduction of ICS!. Visual observation of denuded oocytes was possible and many
morphological features, normal and abnormal, can be observed. Immature oocytes can also be
identified and it was shown that they could be successfully matured in vitro before injection.
In this study transmission electron microscopy (TEM) was used to study abnormalities in oocyte
morphology. The standard method was adapted and modified for single cell TEM. The
abnormalities observed included lysosomal and non-lysosomal degeneration (yellowish or darkly
coloured oocytes), degeneration and vacuole formation (vacuolated oocytes), large secondary
lysosomes filled with multiple small lipid droplets - lipofuscin body (refractile body) and a
fragmented oocyte. It was also possible to study at ultrastructural level, possible reasons for
fertilization failure in ICS!. Different stages of oocyte activation failure, cytoplasmic immaturity,
sperm cell extrusion, abnormal sperm cell decondensation, female spindle abnormalities and
technique related factors were observed. TEM was also successfully implemented to elucidate the reason for infertility in a patient with a
longstanding, unexplained history of infertility. TEM evaluation of two of the patient's unfertilized
oocytes revealed a spindle abnormality with contributing cytoskeletal anomalies at ultrastructural
level. The modified TEM technique offers a valuable tool to study this small, but important group
of patients with unexplained infertility. ThisTEM study opened up a new, valuable and interesting
avenue of research with both diagnostic and prognostic value for patients with unexplained
infertility.
ICSI is therefore a valuable method in the treatment of especially male factor infertility. It is the
most advanced fertilization technique developed in the last decade in this field. Not only can
almost all male factor patients be treated, but unexplained female infertility can also be exposed,
studied and hopefully in future also be treated with micromanipulation methods. / AFRIKAANSE OPSOMMING: Die ontwikkeling van die mikromanipulasie tegniek "Intracytoplasmic sperm injection" (ICSI)
het die behandeling van die manlike faktor in infertiliteit, revolusionêr verander. Met die
uitsondering van sommige gevalle van nie-obstruktiewe asoospermia, kan potensieel alle
ander manlike infertiliteits faktore suksesvol met ICSI behandel word. Die enigste voorvereiste
blyk "n bewegende of "n nie-bewegende, maar bewese lewende spermsel te wees.
In hierdie studie word verslag gedoen oor die ontwikkeling en toepassing van die ICSI metode in
die Eenhed vir Reproduktiewe Biologie by Tygerberg Hospitaal. 'n Analise van 5 jaar se resultate
na die implementering van die ICSI metode het gewys dat die semen parameters, sperm
morfologie, motiliteit en konsentrasie, nie "n effek op bevrugting- en swangerskapsyfers gehad
het nie. Pasiënte wat, as gevolg van ontoereikende semen parameters, nie met die klassieke
metodes, in vitro bevrugting (IVB) of gameet intrafallopiusbuis terugplasing (GIFT) behandel kon
word nie, kon suksesvol met ICSI behandel word. Daar was selfs "n geval van manlike infertiliteit
as gevolg van globosoospermie, wat suksesvol met ICS behandel is.
Die ICSI metode het dit ook moontlik gemaak om uitstekende bevrugting- en swangerskap
resultate met testikulêre spermatosoa .(vars en gevries) te bereik. Die bevriesing van
testisweefsel het ook bygedra tot beter hantering van sulke pasiënte. Herhaalde testisbiopsies
word uitgeskakel en die koórdinasie van die verkryging van die manlike en vroulike gamete, word
ook vergemaklik wanneer testisweefsel in gevriesde vorm beskikbaar is. Die studie het verder
getoon dat wanneer testikulêre weefsel geïnkubeer word (om spermatosoa te laat matureer), die
swangerskapsyfers verhoog was.
Dit is dus duidelik dat die ICSI metode net so suksesvol soos die IVB en GIFT metodes toegepas
kan word, selfs en veral in gevalle van erge manlike faktor infertiliteit.
Die studie het ook verder getoon dat die plek waar embrios teruggeplaas word, asook die
embriokwalitiet van teruggeplaasde embrios, belangrike bydraende faktore in die ICSI
swangerskapsukses was. Embrioterugplasing in die buis van fallopius en terugplasing van
embrios wat vroeë 2-sel deling, 26 uur na ICSI getoon het, is uitgewys as faktore wat ICSI
swangerskap betekenisvol verbeter het. Dit was moontlik om "n swangerskapsyfer van ongeveer
40%, sootgelyk aan die van GIFT sonder "n erge manlike faktor, te bereik met die terugplasing
van ten minste een vroeë deler embrio in die fallopiese buis.
Die ICSI tegniek het ook indirek bygedra tot nuwe insigte met betrekking tot die rol wat die
vroulike eiersel (oësief in ICSI bevrugting speel. Oósiete word gestroop van hulomringende selle
vir die ICSI proses en kan dan maklik vir hul normale en abnormale morfologiese eienskappe
evalueer word. Oësiete wat immatuur is kan ook so geïdentifiseer word en dit is moontlik om hulle
suksesvol te matureer voor mikro-inspuiting.
Transmissie-elektronmikroskopie (TEM) is in die studie gebruik om die ultrastruktuur van
onbevrugde en abnormale oësiete te bestudeer. Hiervoor is "n bestaande tegniek gemodifiseer vir die hantering van "n enkele sel, in hierdie geval die oosiet. Lisasomale en nie-lisosomale degenerasie (oósiete wat geelof donker van kleur voorkom), degeneratiewe tekens en vakuole
(oësiete met vakuole), groot sekondêre lisosome gevul met klein lipieddruppels ('refractile body')
en 'n gefragmenteerde oosiet was van die morfologies abnormale eienskappe wat ultrastruktureel
geïdentifiseer is. Moontlike faktore wat 'n rol kan speel in nie-bevrugting na ICSI kon ook op
ultrastrukturele vlak met die tegniek geïdentifiseer word. Hierdie faktore het die volgende
ingesluit: die onvermoë van verskillende stadiums van oosiet aktivering, sitoplasmatiese
immaturiteit, uitwerping van die spermsel na die periviteliene spasie, abnormale spermsel
dekondensasie, vroulike spoelvormings abnormaliteite en tegniekgekoppelde faktore.
Die TEM tegniek is ook suksesvol aangewend om die infertiliteitsprobleem van 'n pasiënt wat vir
etlike jare aan onverklaarbare infertiliteit gely het, te identifiseer. TEM het op die ultrastrukturele
vlak gewys dat daar 'n spoel abnormaliteit in twee van haar onbevrugde oëslete was. TEM kan
dus baie vrugbaar gebruik word in hierdie groep pasiënte om onverklaarbare infertiliteit, wat
andersins ongeïdentifiseerd sou bly, te verklaar.
Die ICSI metode is die mees revolusionêre tegniek wat die afgelope dekade vir die behandeling
van veral manlike infertiliteit ontwikkel en baie suksesvol toegepas is. Die metode ook kan 'n
bydraende rol speel in die hantering van onverklaarbare infertiliteit veral ten opsigte van die
vroulike gameet. In die toekoms is dit moontlik dat selfs hierdie probleem met nuwe
mikromanipulasietegnieke opgelos sal kan word.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/51790 |
| Date | 12 1900 |
| Creators | Windt, Marie-Lena |
| Contributors | Kruger, T. F., Stellenbosch University. Faculty of Medicine & Health Sciences. Dept. of Obstetrics & Gynaecology. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 180 p., 19 p. of plates : ill. |
| Rights | Stellenbosch University |
Page generated in 0.0083 seconds