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Many tests are used to evaluate female
fertility by determining several factors:
- Are eggs that will fertilize recruited during
each ovulatory cycle?
- Is the egg ovulated ( released from the ovarian
follicle ) regularly each month?
- Does the egg travel unimpeded
through the fallopian tubes to the site of fertilization?
- Once fertilized, can the embryo progress and implant
into the lining of the uterus?
- Is the endometrium adequately prepared to accept
and support the embryo? Once the embryo has implanted, can the pregnancy
be maintained to term?
The human reproductive process is very
complex. However, for the purpose of evaluation, the most important and
basic components include the following:
-
Sperm must be deposited close to
the cervix near the time of ovulation, ascend into the fallopian tubes,
and have the capacity to fertilize the oocyte ( male
factor infertility ).
-
Ovulation of a mature oocyte must
occur, ideally on a regular, predictable, cyclic basis ( ovarian
factor ).
-
The cervix must capture, filter,
nurture, and release sperm into the uterus and fallopian tubes ( cervical
factor ).
-
The fallopian tubes must capture
ovulated ova and effectively transport sperm and embryos ( tubal
factor ).
-
The uterus must be receptive to embryo
implantation and capable of supporting subsequent normal growth and
development
( uterine factor ).
The infertility evaluation is designed
to isolate and test the integrity of each of these components, insofar
as that is possible, and to identify any abnormalities that might impair
or prevent conception.
There are several standard screening
tests that will be conducted during the infertility workup. Additionally,
numerous fertility tests will also be ordered.
Pap smear screening is recommended for
all sexually active women who have a cervix. A blood type, Rh factor,
and antibody screening ( in Rh - negative women ) also are recommended,
if not already known.
The American College of Obstetricians and
Gynecologists and the American College of Medical Genetics recommend that
screening for cystic fibrosis is available to all couples seeking preconception
or prenatal care and that screening should be specifically offered to
couples in ethnic or racial groups considered at higher risk for carrying
a cystic fibrosis mutation ( Caucasians, particularly those of Ashkenazi
Jewish descent ).
All women who are attempting to conceive
in whom previous rubella infection or vaccination cannot be documented
should be tested for rubella immunity and vaccinated if seronegative.
Pregnancy should be delayed for three months following vaccination because
of the theoretical risk of the vaccine virus affecting a fetus.
Screening for sexually - transmitted
infections ( STIs ) is recommended for all women at moderate to high risk
for infection. The CDC recommends screening all pregnant women for syphilis,
hepatitis B, and chlamydia; women at high risk for gonorrhea and hepatitis
C; and voluntary screening for HIV. Before therapeutic donor insemination
and in prospective recipients of donor oocytes or embryos, the American
Society for Reproductive Medicine ( ASRM ) recommends STI screening for
both partners.
For male partners of women to be
inseminated, the ASRM considers HIV - 1 screening mandatory; recommends
thorough STI screening to include syphilis, hepatitis B and C, cytomegalovirus
antibody, HIV - 1 and HIV - 2, and human T - cell lymphocyte virus ( HTLV
) types I and II; and suggests that screening for chlamydia and gonorrhea
also be performed at the discretion of the physician. For recipients of
donor oocytes or embryos and their male partners,
the ASRM recommends screening for syphilis, hepatitis B and C, CMV, and
HIV - 1.
Male infertility
contributes to 35% - 45% of infertility cases; therefore, semen
analysis is always an appropriate and important initial step in the
evaluation of the infertile couple. A frankly abnormal semen analysis
is indication for additional evaluation that may be conducted by the gynecologist
but is most often performed by a urologist or other specialist in male
reproduction. When semen quality is normal, attention turns to the female
partner.
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