Male
Infertility
The limited effectiveness of treatments for male infertility
has provided a sizable number of individuals who desire IVF
to overcome problems with sperm. Early experience with male
factor infertility in IVF indicated that even placing sperm
in the dish with the oocyte still left many sperm specimens
with a handicap. Fertilization rates tended to be approximately
one-half those achieved with normal sperm, and the pregnancy
rates were correspondingly lower. On occasion, however, fertilization
occurred with surprisingly few sperm available.
IVF provides the ability to visualize the results of sperm and
egg interaction and thus to quickly determine if specific manipulations
of the sperm can affect fertilization. A variety of sperm treatments
have been attempted. One approach is to increase the number
of sperm in the dish with the hope that even with abnormal specimens
there will be a few normal sperm that can achieve fertilization.
By increasing the numbers in each dish there will be more normal
sperm per egg. A second approach is to isolate the best sperm
from the specimen, not by the standard swim-up technique, but
by using a variety of gradients. In some hands this has provided
increased fertilization rates, but others have not found it
to be a significant advantage. Similar contradictory results
have been reported with drug treatment of the semen; the most
popular such treatment has utilized pentoxifylline, which acts
by increasing cyclic AMP in cells.52 The drug must be washed
out from the sperm specimen before incubation with the egg because
it may have adverse effects. Another treatment that has been
used to enhance sperm is incubation in follicular fluid.53 In
men with sperm autoantibodies, in vitro fertilization is correlated
with the extent the sperm are covered with antibodies. (Source:
Clinical Gynecologic Endocrinology and Infertility. Speroff,
Glass, and Kase. Lippincott Williams & Wilkins. 1999)
