The initial infertility evaluation should always try to document
ovulation. This can not always be done with absolute certainty.
The human egg is microscopic. This means that it is invisible
to the naked eye and cannot be seen without the aid of a microscope.
Therefore, when you think about it the only real way to absolutely
confirm the egg's release from the ovary is to achieve a pregnancy
or to identify the egg under the microscope after flushing the
microscopic egg out from the pelvis, fallopian tube or uterus
(which is possibly immoral and certainly both impractical and
difficult).
Useful methods of documenting ovulation include:
* (1) obtaining the history of regular menstrual cycle intervals
off all medication.
This is the oldest technique of documenting ovulation and it is
both simple and fairly reliable. Additional support occurs if
each menstrual flow is consistent in amount, there are premenstrual
symptoms reflecting that hormonal shifts are occurring, and the
menstrual intervals have been regular for a long period of time
(eg., years). It should be confirmed that the cycle intervals
are regular off all medication since some medications regulate
the menstrual cycle (such as birth control pills).
* (2) the basal body temperature (BBT) record
This is another potentially useful source of information about
ovulation. A woman's early morning temperature increases a little
more than a half degree Fahrenheit after ovulation due to the
effect of increased progesterone on her temperature regulator
(which is in the hypothalamus of the brain). Typically, the woman's
temperature rises from less than 98 degrees (prior to ovulation)
to greater than 98 degrees (after ovulation). The classic biphasic
pattern on the BBT record is good supportive evidence that ovulation
is occurring. Unfortunately, up to 10% of women may not have a
biphasic BBT record despite regular ovulation.
* (3) cervical mucus characteristics
The cervical mucus is strongly influenced by estrogen and progesterone.
The most commonly noted changes that can be seen by a woman include
amount and elasticity (stringy quality) of the mucus. Just prior
to ovulation, there is abundant elastic clear mucus at the cervix,
the time of "maximal wetness." In my experience, there
are only a relatively small handful of women sufficiently motivated
to consistently check for changes in mucus. Although popular in
some circles, I have not encouraged use of this method of detecting
ovulation.
* (4) ovulation predictor kits
A modern and accurate way to test for ovulation relies on detection
of the LH surge with ovulation predictor kits. The sudden increase
in circulating LH when there is a mature egg in the ovary triggers
that egg to undergo the final maturational steps that allow it
to become fertilized by sperm and also triggers the egg's release
from the ovary. One advantage of the ovulation predictor kits
is detection prior to ovulation. These kits become positive about
a day prior to ovulation since the circulating LH must be metabolized,
processed through the kidneys and excreted from the bladder in
urine to allow for detection. The ovulation predictor kits are
useful in timing intercourse or artificial inseminations with
sperm.
* (5) random luteal phase progesterone concentration
The luteal phase of the menstrual cycle is characterized by high
circulating progesterone concentrations. The uterine endometrium
undergoes structural changes in the presence of progesterone that
can be seen histologically (under the microscope). Pathologists
can date the endometrium with respect to the day of ovulation
with good accuracy. Therefore, a luteal phase endometrial biopsy
has been used to confirm ovulation. Also, a random serum progesterone
concentration in the luteal phase may confirm ovulation. One disadvantage
of the random serum progesterone concentration is that the level
is pulsatile with large changes every 5-15 minutes, so that if
you obtained 3 different serum levels on the same day you could
receive three very different concentrations. Cutoffs for deciding
that ovulation has occurred are controversial with a wide range
of accepted values from about 4 ng/ml to 10 ng/ml.
In my experience, the other available methods of ovulation detection
are considerably more involved and are rarely warranted in the
clinical setting. The additional effort and expense of this testing
can be significant and the additional information gained is usually
not useful clinically. These additional techniques include
* (1) serial ultrasonography,
Daily transvaginal sonograms look for the development and eventual
collapse of an ovarian follicle. This is expensive, time consuming
and not much more informative than the ovulation predictor kit.
It is also not uncommon to "miss ovulation" since the
follicle can collapse with the release of the egg and reaccumulate
with fluid to form the corpus luteum cyst (which can look like
a follicle) between ultrasounds.
* (2) frequent blood sampling,
Blood can be sampled up to every few (usually 10-15) minutes for
days looking for subtle changes in hormone values that reflect
ovulation. This testing is the "gold standard" for ovulation
detection but is usually only useful in research where the additional
gathered information may change the research findings. Clinically,
this level of precision is not needed.
* (3) flushing the body for eggs or embryos,
This is restricted to experimental settings, where the pelvic
cavity or the uterine cavity is flushed and the washings are examined
microscopically for the presence of eggs or embryos. This can
involve minor surgical procedures, there are serious ethical and
moral concerns and the retrieved products are not usually viable.
More information on the causes and treatments of miscarriages is available here.
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