Infertility
What is it?
Infertility is the failure of a couple to conceive a pregnancy after
trying to do so for at least one full year. In primary infertility,
pregnancy has never occurred. In secondary infertility, one or both
members of the couple have previously conceived, but are unable to
conceive again after a full year of trying.
Who gets it and what are its causes?
Currently, in the United States, about 20% of couples struggle with
infertility at any given time. Infertility has increased as a problem
over the last 30 years. Some studies pin the blame for this increase on
social phenomena, including the tendency for marriage to occur at a
later age, which means that couples are trying to start families at a
later age. It is well known that fertility in women decreases with
increasing age, as illustrated by the following statistics:
- Infertility in married women ages 16-20=4.5%
- Infertility in married women ages 35-40=31.8%
- Infertility in married women over the age of 40=70%.
Nowadays, individuals often have multiple sexual partners before they
marry and try to have children. This increase in numbers of sexual
partners has led to an increase in sexually transmitted diseases.
Scarring from these infections, especially from pelvic inflammatory
disease (a serious infection of the female reproductive organs, most
commonly caused by gonorrhea) seems to be in part responsible for the
increase in infertility noted. Furthermore, use of some forms of the
contraceptive called the intrauterine device (IUD) contributed to an
increased rate of pelvic inflammatory disease, with subsequent scarring.
However, newer IUDs do not lead to this increased rate of infection.
To understand issues of infertility, it is first necessary to
understand the basics of human reproduction. Fertilization occurs when a
sperm from the male merges with an egg (ovum) from the female, creating
a zygote that contains genetic material (DNA) from both the father and
the mother. If pregnancy is then established, the zygote will develop
into an embryo, then a fetus, and ultimately a baby will be born.
When fertilization occurs, the resulting cell (which now contains
genetic material from both the mother and the father) is called the
zygote. This single cell will divide into multiple other cells within
the fallopian tube, and the resulting cluster of cells (called a
blastocyst) will then move into the womb (uterus). The uterine lining (endometrium)
has been preparing itself to receive a pregnancy by growing thicker. If
the blastocyst successfully reaches the inside of the uterus and
attaches itself to the wall of the uterus, then implantation and
pregnancy have been achieved.
What are the symptoms?
Unlike most medical problems, infertility is an issue requiring the
careful evaluation of two separate individuals, as well as an evaluation
of their interactions with each other. In about 3-4% of couples, no
cause for their infertility will be discovered. About 40% of the time,
the root of the couple's infertility is due to a problem with the male
partner; about 40% of the time, the root of the infertility is due to
the female partner; and about 20% of the time, there are fertility
problems with both the man and the woman.
The main factors involved in causing infertility, listing from the
most to the least common, include:
- Male problems: 35%
- Ovulation problems: 20%
- Tubal problems: 20%
- Endometriosis: 10%
- Cervical factors: 5%.
Medical treatment
If a couple is infertile because the woman is not ovulating,
infertility drugs may be prescribed to stimulate the ovulation. The
first step usually is to try a drug such as Clompiphene. If that doesn’t
work, human chorionic gonadotropin (HCG) may be tried, usually in
combination with other infertility drugs. Clompiphene and HCG may also
be used to treat other conditions in both males and females.
Treatment with infertility drugs increases the chance of multiple
births. Although this may seem like a good thing to couples who want
children badly, multiple fetuses can cause problems during pregnancy and
delivery and can even threaten the babies’ survival.
Surgical treatment
Assisted reproductive techniques include invitro fertilization (IVF),
gamete intrafallopian transfer (GIFT), and zygote intrafallopian tube
transfer (ZIFT). These are usually used after other techniques to treat
infertility have failed.
Invitro fertilization involves the use of a drug to induce the
simultaneous release of many eggs from the female's ovaries, which are
retrieved surgically. Meanwhile, several semen samples are obtained from
the male partner, and a sperm concentrate is prepared. The ova and sperm
are then combined in a laboratory, where several of the ova may be
fertilized. Cell division is allowed to take place up to the embryo
stage. While this takes place, the female may be given drugs to ensure
that her uterus is ready to receive an embryo. Three or four of the
embryos are transferred to the female's uterus, and the wait begins to
see if any or all of them implant and result in an actual pregnancy.
Success rates of IVF are still rather low. Most centers report
pregnancy rates between 10-20%. Since most IVF procedures put more than
one embryo into the uterus, the chance for a multiple birth (twins or
more) is greatly increased in couples undergoing IVF.
GIFT involves retrieval of both multiple ova and semen, and the
mechanical placement of both within the female partner's fallopian
tubes, where one hopes that fertilization will occur. ZIFT involves the
same retrieval of ova and semen, and fertilization and growth in the
laboratory up to the zygote stage, at which point the zygotes are placed
in the fallopian tubes. Both GIFT and ZIFT seem to have higher success
rates than IVF.
Physician's Who Treat Infertility
This information has been designed as a comprehensive and quick reference
guide written by our health care reviewers. The health information written
by our authors is intended to be a supplement to the care provided by your
physician. It is not intended nor implied to be a substitute for
professional medical advice.
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