If the ovaries do not produce eggs at all, or if the eggs
are of such weak quality that they cannot be fertilized or
developed, one alternative is to use donor eggs.
The causes for problems in the ovaries may be congenital
(for example chromosome errors) or those which develop later
in life (e.g. endometriosis, premature menopause, causes due
to chemotherapy or age). The carefully screened donor undergoes
a similar hormonal treatment as in in vitro fertilization
in general. After the eggs have been retrieved, they are fertilized
with the sperm of the recipient's spouse. The fertilized eggs
are then transferred into the uterine cavity of the recipient.
The recipient also undergoes hormonal treatment, the purpose
of which, in this case, is to prepare the uterus to receive
the embryos. This hormonal treatment involves a combination
of estrogene (tablets or patch) and progesterone (vaginal
tablets) and normally continues through to the 10th week of
pregnancy. The success rates with egg donation treatment are
equal to those of in vitro fertilization in general and the
spare good quality embryos which are not transferred can be
frozen.
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