Vitro Fertilization

Human in vitro fertilization is selection of embryos for the transfer to the
uterus. The eggs are surgically removed from a woman's ovaries and placed in a
carefully prepared broth called human tubal fluid. Six hours later, the
husband's sperm cells are added. The evidence of fertilization was detected
approximately 16 hours later. Later on, the scientists select four embryos that
are actively dividing and carefully inserts them into the woman's uterus through
her cervix. In another 10 days, a laboratory pregnancy test will tell her if the
embryo has attached to her uterine wall. The average rate of achieving pregnancy
being 35 percent. For fertilization of a human egg to occur, whether it be in a
petri dish or nature's setting(a woman's fallopian tube), a series of intricate
events must occur to produce a viable egg in the women and healthy sperm cells.

Recently we have learned in class; the development of a ripe egg and its release
into the fallopian tube is called ovulation, which is controlled by hormones
produced by the brain, pituatory gland and ovaries. The leading cause of
abnormal ovulation though, is caused by polycystic ovary syndrome. There is very
little known how or why it is caused, but we do know those patients with the
syndrome have increased insulin levels. When ovulation does occur, the newly
released egg enters a fallopian tube, ready to encounter sperm cells that have
made it through the selective hurdles of a woman's urinary tract. One hurdle the
sperm cells encounter is the cervix, which acts as a biological filter. The
cervix filters out all the unhealthy or abnormally shaped sperm. Once a viable
egg is produced and sperm cells have entered the fallopian tubes, fertilization
is possible- if the two types of cells successfully meet. The events of early
reproduction are among the most fascinating, most complex, but least understood
in human biology. This class has taught me to share a fundamental desire for
this significant process and has helped me understand the events that ensure the
continuation of human life.