Both
ZIFT and TET are performed on a woman who receives donor eggs because
she cannot produce her own or difficulties have been encountered
in previous "in vitro" fertilization (IVF) treatment in
replacing the embryos into the uterus through the cervix. Embryo
(Zygotes) developed from eggs fertilized in the laboratory are returned
to the Fallopian tube (a maximum of three at one time) so the Fallopian
tubes must be normal.
In
ZIFT, the transfer is done 24 hours after fertilization while
in TET, the embryos (zygotes) are allowed to grow and divide for
48 hours before returned to the Fallopian tube. They are a day-case
procedures under a general anesthetic using "keyhole"
surgery. Mild-to-moderate pain may be experienced for a few day
after the operation but can be relieved with painkillers.
Hormonal
treatment to help maintain the pregnancy is given for the following
2 weeks, which can be either three injections with human gonadotrophin
(hCG) or progesterone tablets inserted into the vagina daily.
Oestrogen may also be required for patients receiving donor eggs.
The
success rate for both ZIFT and TET is approximately 40-50% depending
on the age of the patient.
Zygote intra-Fallopian transfer (ZIFT)
and
Tubal embryo transfer (TET)
- Zygote
intra-Fallopian transfer (ZIFT) and tubal embryo transfer (TET)
are performed when donor eggs are being given to a woman who cannot
produce her own, or when difficulties have been encountered in
previous in vitro fertilization (IVF) treatments in replacing
the embryos into the uterus through the cervix. The Fallopian
tubes must be normal.
- In
both ZIFT and TET, embryos (zygotes) that have developed from
eggs fertilized in the laboratory are returned to the Fallopian
tube. A maximum of three embryos are returned at one time.
- In
ZIFT, the embryos (zygotes) are returned to the Fallopian tube
24 hours after fertilization. In TET, the embryos (zygotes) are
allowed to grow and divide for 48 hours before being returned
to the Fallopian tube.
- Both
ZIFT and TET are carried out as a day-case procedures under a
general anesthetic using 'keyhole' surgery.
- Mild-to-moderate
pain may be experienced for a few days after the operation, but
this can be relieved with painkillers.
- Hormonal
treatment to help maintain the pregnancy is given for the
following 2 weeks. This involves either three injections with
human chorionic gonadotrophin (hCG) or daily treatment with progesterone
tablets inserted into the vagina. Patients receiving donor eggs
may also require oestrogen.
- The
success rate for both ZIFT and TET is about 40-50%, but varies depending
on the age of the patient.
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