from the book How to Have a Baby:
Overcoming Infertility
by Dr. Aniruddha Malpani, MD and Dr. Anjali Malpani, MD.
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Ovulation -- Normal and Abnormal (Page 1)
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Table of Contents
How is ultrasound used to monitor ovulation ?
How do I use ovulation prediction kits ( OPK)
?
How can I use the new pocket microscopes to
track
ovulation ?
What blood tests can be used to predict
ovulation ?
What happens when ovulation is abnormal ?
What are the blood tests which are used to
diagnose problems with ovulation ?
What is ovarian failure ?
What are the treatments are available for
inducing ovulation?
How is ultrasound used to monitor ovulation ?
The egg develops within a follicle in the ovary. This follicle is a
thin-walled structure containing fluid with the egg attached to the
wall. Usually, only one follicle develops per month. This follicular
growth can be monitored by ultrasound,
usually done with a vaginal probe, which projects an image of the ovary
onto a screen.
The follicle appears as a
circular fluid-filled bubble on the screen, and can be seen when it is
about 7 to 8 mm in size. It grows at about 1 to 2 mm per day, and is
ready for ovulation when it measures 18 to 25 millimeters in diameter.
Following ovulation, the follicle usually disappears from the scan
picture completely and this is the best evidence of ovulation.
Often, at the same time,
fluid can also be detected in the abdomen behind the uterus - this is
the follicular fluid which is released when the follicle ruptures.
Defects detectable by ultrasound are follicles that do not grow at all,
or do not grow to a big enough size, or occasionally follicles that do
not rupture at the appropriate time (luteinised unruptured follicle).
Since ultrasound allows
assessment of follicular development, it is especially useful for
patients having timed intercourse or having ovulation regulated with
fertility drugs. It is usually done on a daily basis, from about the
11th day of the cycle.
Follicle tracking on ultrasound usually takes about
5 minutes to perform. No preparation is needed; except that the bladder
must be emptied before the scan. Ask to see the picture of the follicle
on the monitor - and you should be able to see the growth of the
follicle and its rupture for yourself on the screen.
Older ultrasound machines used abdominal probes .
These require that the patient have a full bladder, so that the sound
waves can reach the ovary. Not only are they much more uncomfortable for
the patient (who has to sit waiting till the bladder is almost bursting
) but the quality of the pictures is also much poorer as compared to the
vaginal scan.
How do I use ovulation prediction kits ( OPK)
?
Ovulation prediction test kits (OPK) are available abroad (or in India
at a few chemists) over the counter . If you live in India, you can also
buy them from our online
store. These kits detect LH which is
produced in large quantities shortly before ovulation and can be found
in the urine . Once the LH surge has occurred, ovulation usually takes
place within 12 to 44 hours. Urine testing is started about two days
prior to the expected day of ovulation and continues until the test
becomes positive. The urine should be collected at the same time every
day - and testing the first morning urine sample is a good idea.
If your menstrual cycles are irregular, testing
should be timed according to the earliest and latest possible dates of
ovulation. For example, if your cycle ranges between 27 and 34 days, you
could possibly ovulate between days 13 and 20. Therefore, testing should
begin on day 11 and continue until ovulation is indicated or through day
20. There is an 80 percent chance of detecting ovulation with five days
of testing and a 95 percent chance with ten days of testing.
Occasionally, ovulation may not occur in a particular cycle. If the
ovulation prediction test has been timed and performed accurately and
has not turned positive, you should discontinue testing and begin again
with your next menstrual cycle. Persistent failure of the test to turn
positive may indicate a problem with regard to ovulation.
Once a test has registered positive, indicating that
ovulation is about to take place, it is no longer necessary to continue
testing. Remaining tests in a kit may be saved and used in the following
menstrual cycle if pregnancy does not occur.
Ovulation prediction kits offer the advantage that
they allow you to predict when ovulation will occur - thus maximising
the chances that intercourse will be timed at your most fertile period.
They can also be done in the privacy of your own home. However, they are
expensive; and some of the kits have very tedious and involved testing
procedures, so that errors are not uncommon.
A newer device, The ClearPlan EasyTM Fertility
Monitor, is a palm-sized, electronic system, that provides information
about fertility status by interpreting the levels of two hormones,
estrogen and luteinizing hormone, in the urine. You need to test your
urine for the presence of these, using dip sticks, and the information
is then input into the system, which uses it to calculate your fertile
days.
How can I use the new pocket microscopes to
track
ovulation ?
Another way of monitoring ovulation uses a pocket microscope, to check
for the phenomenon of "saliva ferning." You need to let your saliva dry
on a glass slide, and then examine it under the devise, to check for
ferning. Prior to ovulation, the saliva shows the presence of
crystallisation or ferning when it dries, and this suggests that
ovulation will occur soon. Though these devices are now commercially
available, their reliability is still unclear.
What blood tests can be used to predict
ovulation ?
The growing follicle secretes the hormone estradiol in increasing
amounts and its blood level rises rapidly several days prior to
ovulation. If ovulation is being induced through fertility drugs,
estradiol blood tests may be done on a daily basis in order to determine
if the developing follicles are growing properly. Normally, the
estradiol blood levels should increase rapidly (as a rule of thumb, they
double every 24 hours).
Since the luteinizing hormone (LH) blood level rises
rapidly just before ovulation (this is called the LH surge), frequent
blood samples for measuring the LH level can also be taken a few days
prior to the anticipated time of ovulation in an attempt to predict when
the follicle is mature and ready for ovulation.
What happens when ovulation is abnormal ?
Abnormalities of ovulation may appear in several ways. Menstrual cycles
shorter than 21 days or longer than 35 days are often associated with
anovulation. In addition, patients may skip menstrual periods for time
intervals of three months or more and this is called oligomenorrhea
(infrequent periods) . If the periods stop entirely, this is called
amenorrhea.
Many hormonal systems work together to produce
regular menstrual periods, and the blood levels of the hormones that
make up these systems need to be tested in order to determine the reason
for the ovulatory disorders.
What are the blood tests which are used to
diagnose problems with ovulation ?
The hormone blood tests, which are usually done on
the third day of your cycle, include:
The FSH level: The FSH level gives a good
idea of the ovarian reserve ( ovarian functional capacity) - an index of
the number of eggs remaining in the ovaries. A high FSH level
suggests that the ovary has either failed or has started to fail. If the
FSH level is very high (in the menopausal range) then the diagnosis is
ovarian failure. If the level is borderline, then some doctors will do a
clomiphene citrate challenge test , which allows for an earlier diagnosis
of failing ovaries. Even women with regular menstrual cycles may have
poor egg quality, as reflected by an elevated FSH levels. This is called
oopause. Ovarian reserve can also be assessed by measuring
the levels of the ovarian hormone inhibin in the blood. Low levels of
inhibin suggest poor ovarian function. However, this test is still new
and is not
easily available.
A very low FSH level suggests hypogonadotropic hypogonadism. This seemingly verbose term simply means
that the ovary in these patients is not working properly because of
inadequate production of FSH by the pituitary gland. However, in most
anovulatory patients, the FSH level will be in the normal range, and
this can be reassuring.
The LH level: This is the other gonadotropin
hormone produced by the pituitary; and provides much the same
information the FSH level does. Another useful test is the LH:FSH ratio
which is normally 1:1. If, however, the LH level is much higher than the
FSH level,this suggests a diagnosis of polycystic ovarian disease.
Thyroxine and TSH. These test for thyroid
function. The thyroxine level is high in patients with overactive
thyroid glands (hyperthyroidism). In patients with decreased thyroid
function (hypothyroidism), the TSH level is increased.
Prolactin: Prolactin is a hormone produced by
the pituitary gland that induces lactation or milk formation.. High
prolactin levels (hyperprolactinemia) can interfere with ovulation . A
milky discharge from the breast nipple , not related to pregnancy or
nursing , is called galactorrhea, and this is a telltale symptom of high
prolactin levels and needs to be investigated. If the prolactin level is
elevated, the doctor will need to recheck it to confirm it is
persistently high. There are many reasons for an elevated prolactin
level, including certain drugs as well as stress. In some women, the
reason for a high prolactin level can be a small tumour in the pituitary
gland. This is called a prolactinoma or microadenoma, and the doctor may
advise you have an X-ray of the skull ( or even a CT scan or MRI scan)
to rule out this possibility. However, most infertile women with
hyperprolactinemia can be easily treated with a medicine called
bromocryptine, which is a dopamine agonist medication . Another
medication which can be used to treat hyperprolactinemia is oral
cabergoline, which is usually taken twice a week. Only if the pituitary
tumour is very large ( microadenoma) is surgical removal needed, and
this is very uncommon.
What is ovarian failure ?
Ovarian failure is a disease in which the ovaries fail to produce eggs.
This disease is uncommon, occurring in only about 10% of women whose
periods do not occur at all, a condition called amenorrhea (absence of
periods). Ovarian failure may be genetic (for example, in girls with
Turner's syndrome, a chromosomal disorder) or may be acquired (for
example, following radiation or chemotherapy for cancers; surgery to
remove the ovaries for treating ovarian cancer or severe endometriosis;
autoimmune ovarian failure; or for unexplained reasons.) Ovarian failure
is diagnosed by finding a high FSH level. In such patients it is usually
not possible to stimulate ovulation and they have any eggs, and they
suffer a premature menopause. The only effective medical treatment for
these patients is the use of
donor egg IVF . However, in a
very small proportion of these patients, ovulation can resume
spontaneously.
What are the treatments are available for
inducing ovulation?
What forms of treatments are available for inducing ovulation?
The most commonly prescribed medicines for induction
of ovulation include the following: clomiphene citrate, human menopausal
gonadotrophin (HMG) and follicle stimulating hormone (FSH), HCG (human
chorionic gonadotropin), bromocriptine, GnRH (gonadotropin releasing
hormone) and GnRH analogue.
For women with hypogonadotropic hypogonadism (low
FSH and LH levels), the treatment of first choice is HMG. This is
effective replacement therapy; and excellent pregnancy rates can be
achieved in these women.
For women affected by hyperprolactinemia, the drug
of first choice is bromocriptine.
For most other women, the drug of first choice is
clomiphene - the "workhorse" of ovulation induction. If this does not
work, then HMG is resorted to.
Poor responders to HMG can be treated with GnRH
analogues in conjunction with the HMG; or by adding a hormone called the
human growth hormone.(HGH).
HCG (human chorionic gonadotropin) is given to
trigger off the release of the egg.
In patients with high androgen levels (high blood
levels of male hormones), dexamethasone can be used as an adjunct, since
this suppresses androgen production.
You can read more about these medicines and how they
are used
in the Chapter on
Understanding Your Medicines.
Often ovulation induction requires an investment of
time, money, energy and emotion before a satisfactory response is
achieved. After all, every woman is different and there can be no
standard "formulae". Careful monitoring of the response to ovulation
induction is the key to therapy - and this usually involves daily
ultrasound scans and/or blood tests. It is often a tedious process -
which may involve "trial and error" to tailor the therapy to the
individual patient's ovulatory response. With the treatments available
today, however, correcting ovulatory dysfunction is one of the most
rewarding and successful of infertility treatments.
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Older Woman
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Ovulation -- Normal and Abnormal (Page 1)
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