Transcript Prolactin

Introduction
• Fertility denotes the ability of a man and woman to
reproduce; conversely, infertility denotes the lack of
fertility—an involuntary reduction in the ability to
produce children.
• When a couple has been engaging in regular, unprotected
sexual intercourse for at least 1 year without conceiving,
the couple is considered infertile.
 In about one third of cases, a male factor is the
predominant cause;
 in another one third, the female factor predominates; and
 in another onethird, no cause is found in either partner.
• The workup for infertility starts with a complete history and
physical exam for both the woman and the man, including their
sexual history. A rational approach is to put each partner through
a series of tests that generally uncover a vast majority of the
contributing factors of infertility. These tests usually take 2 to 3
months to complete.
• Standard pretest and posttest care for couples undergoing fertility
testing includes the following:
– Provide information and support. Be sensitive to the couple’s need
for privacy and confidentiality.
– Maintain a communication network about new procedures, tests, and
treatments.
– Help couples deal with feelings of sadness and loss. Assist couples to
deal with the effects of stress and the financial burden during the
diagnostic process.
– Assist couples in arranging work and testing schedules with the least
amount of disruption for the couple.
• Arrange for counseling with experts who understand
the different ways infertility affects someone’s life.
 Tests include evaluation of:
 amenorrhea,
anovulation,
sperm count (angiosperm, oligospermia),
 hormone testing
 hysterosalpingogram
 laparoscopy
 Hysteroscopy
 fertiloscopy,
 Semen analysis,
 postcoital test
 endometrial biopsy
 chromosome karyotype to exclude Kallmann’s
 syndrome.
Hormonal testing
• Hormone testing
• rules pregnancy in or out, chorionic
gonadotropin
• prolactin
• luteinizing hormone [LH]
• follicle-stimulating hormone [FSH]
• thyroid-stimulating hormone [TSH]
• postcoital test
• antisperm antibodies
• Also see estrogen testing.
Pregnancy trimester
• First Trimester (0 to 13 Weeks)
• Second Trimester (14 to 26 Weeks)
• Third Trimester (27 to 40 Weeks)
PROLACTIN
• Prolactin (PRL, luteotropic hormone) is secreted from lactortrophs
of the anterior pituitary gland in both men and woman.
• It is a protein consisting of a single polypeptide biological action of
the hormone is on the mammary gland where maintenance of milk
production.
• Molecular weight of approximately 23.000 Daltons.
• The gender difference in prolactin does not occur until puberty,
when increased estrogen production results in higher prolactin
levels in females.
• Women normally have slightly higher basal prolactin levels than
men.
• During and following pregnancy, prolactin, in association with
other hormones, stimulates breast development and milk
production.
• High levels of prolactin are normal during
pregnancy and after childbirth while the
mother is nursing.
why women who are breastfeeding (and thus have high levels
of prolactin) usually don’t become pregnant.
• High prolactin levels inhibit secretion of FSH.
Therefore, if your prolactin levels are high,
your ovulation may be suppressed.
• High levels of prolactin appear to inhibit
steroidogenesis as well as inhibiting LH and
FSH synthesis at the pituitary gland.
• The primary biological action of the hormone
is on the mammary gland where it is involved
in the growth of the gland and in the
induction and maintenance of milk
production.
• There is evidence to suggest that prolactin
may be involve in steroidogenesis in the
gonad. Acting synergistically with luteinizing
hormone LH.
• Prolactin is a hormone that plays a role in
fertility by inhibiting follicle stimulating
hormone (FSH) and gonadotropin-releasing
hormone (GnRH), the hormones that trigger
ovulation and allow eggs to develop and
mature.
• It is unclear what role prolactin plays in men,
but it is clearly linked to infertility.
Significance
• The clinical usefulness of the measurement of
prolactin hormone in ascertaining the diagnosis
of hyperprolactinemia and for the subsequent
monitoring the effectiveness of the treatment has
been well established.
• It is also useful in the management of
hypothalamic disease
• Monitoring the effectiveness of surgery,
chemotherapy, and radiation treatment of
prolactin-secreting tumors.
• The prolactin test can also be performed if a
woman is having infertility problems or
irregular menstrual periods and also to rule
out problems with the pituitary gland or
hypothalamus.
• Measurement of plasma prolactin has been used
as an index of response to the injection of TRH,
which stimulates release of prolactin in addition
to stimulating the release of TSH.
• If you are taking medicine for a prolactinoma,
you will have your hormone levels checked at
least once or twice a year.
• Hypersecretion of prolactin can be caused by
pituitary tumors, hypothalamic diseases,
hypothyroid, renal failure, acute exercise and
several medications.
• Hyperprolactinemia inhibits hypogonadism in
men and women with accompanying low FSH
and LH levels.
• Human Prolactin is similar in structure to human
growth hormone(HGH), and both are good
lactogenic.
• Prolactinomas occur in both men and women but
are more commonly diagnosed in women who are
less than 50 years than in older women or men.
• In cases of prolactinoma, the test is carried out
regularly to check the tumor’s response to
treatment.
• High levels of prolactin can also be caused by
pituitary tumors, which can be treated medically or
surgically.
• are the most common hormone-secreting pituitary tumors. Based on its
size, a prolactinoma can be classified as a microprolactinoma (< 10 mm
diameter) or a macroprolactinoma (>10 mm diameter).
• For the interpretation of the finding of an
increased plasma (prolactin), it is important to
enquire about the intake of drug.
• Many centrally acting drugs (phenothiazines,
methyldopa, imipramine) inhibit the release of
prolactin release-inhibiting hormone.
Oestrogens and oral contraceptive may also
cause raised plasma prolactin
• Surgery is often the first treatment for many
types of pituitary adenomas. If you had a
functional (hormone-making) pituitary adenoma,
hormone measurements can often be done within
days or weeks after surgery to see if the
treatment was successful.
• Blood tests will also be done to see how well the
remaining normal pituitary gland is functioning.
• If the results show that the tumor was removed
completely and that pituitary function is normal,
you will still need periodic visits with your
doctor.
• Your hormone levels may need to be checked again in the
• Blood should be drawn using standard venipuncture
techniques and serum separated from blood cells as
soon as possible. Samples should be allowed to clot
for one hour at room temperature, centrifuged for 10
minutes (4°C) and serum extracted. This kit is for
use with serum samples without additives only.
• Avoid grossly hemolytic, lipidic or turbid samples.
• Serum samples to be used within 24-48 hours may be
stored at 2-8°C otherwise samples must be stored at
-20°C to avoid loss of bioactivity and contamination.
Avoid freeze-thaw cycles.
• When performing the assay slowly bring samples
to room temperature.
• It is recommended that all samples be assayed in
duplicate.
• DO NOT USE HEAT-TREATED SPECIMENS.
• This test cannot be made for mother at lactation
period.
• Patient should be avoid Emotional stress and
strenuous exercise.
Procedure
1. Ensure that the patient fasts for 12 hours before testing. Obtain a 5-mL venous
blood
sample (red-topped tube). Serum is used.
2. Procure specimens in the morning, between 8:00 (0800 hours) and 10:00 a.m.
(1000 hours).
Draw in chilled tubes, and keep specimen on ice.
3. Observe standard precautions. Place specimen in a biohazard bag.
The only result of prolactin deficiency in pregnancy is the absence of postpartum
lactation.
Interfering Factors
1. Increased values are associated with newborns, pregnancy, postpartum period,
stress,exercise, sleep, nipple stimulation, and lactation (breast-feeding).
2. Drugs (eg, estrogens, methyldopa, phenothiazines, opiates) may increase values.
3. Dopaminergic drugs inhibit prolactin secretion. Administration of L-dopa can
normalize
prolactin levels in galactorrhea, hyperprolactinemia, and pituitary tumor.
4. Increased levels are found in cocaine abuse, even after withdrawal from cocaine.
5. Macroprolactin can falsely increase test results.
Reference range
• Levels >200 ng/mL or >200 μg/L in a
nonlactating female indicate a prolactinsecreting tumor;
• however, a normal prolactin level does not
rule out pituitary tumor.
What are related tests?
• Serum quantitative HCG measurement
• CT of pituitary fossa
• MRI of head
• MRI of pituitary fossa
• Plasma FSH measurement
• Video EEG
Thyroid dysfunction and infertility
• Thyroid dysfunction is a condition known to
reduce the likelihood of pregnancy.
Additionally, abnormal thyroid hormones
disturb the normal menstrual pattern.
• Measurement of prolactin and thyroid
hormones, especially thyroid stimulating
hormone (TSH), has been considered an
important component of infertility work up in
women.
• Thyroid dysfunctions interfere with numerous
aspects of reproduction and pregnancy.
• Several articles have highlighted the association
of hyperthyroidism or hypothyroidism with
menstrual disturbance, anovulatory cycles,
decreased fecundity and increased morbidity
during pregnancy
•
• Thyroid stimulation by chorionic gonadotropin: The placentae of humans
and other primates secrete huge amounts of a hormone called chorionic
gonadotropin (in the case of humans, human chorionic gonadotropin or
hCG) which is very closely related to LH.
•
TSH and hCG are similar enough that hCG can bind and transduce signalling
from the TSH receptor on thyroid epithelial cells. Toward the end of the first
trimester of pregnancy in humans, when hCG levels are highest, a significant
fraction of the thyroid-stimulating activity is from hCG.
• During this time, blood levels of TSH often are suppressed, as depicted in
the figure to the right. The thyroid-stimulating activity of hCG actually
causes some women to develop transient hyperthyroidism.
• The net effect of pregnancy is an increased demand on the thyroid
gland. In the normal individuals, this does not appear to represent much of
a load to the thyroid gland, but in females with subclinical hypothyroidism,
the extra demands of pregnancy can precipitate clinical disease.
• Increased blood concentrations of T4-binding globulin: TBG
is one of several proteins that transport thyroid hormones in
blood, and has the highest affinity for T4 (thyroxine) of the
group.
• Estrogens stimulate expression of TBG in liver, and the
normal rise in estrogen during pregnancy induces roughly a
doubling in serum TBG concentrations.
• Increased levels of TBG lead to lowered free T4
concentrations, which results in elevated TSH secretion by
the pituitary and, consequently, enhanced production and
secretion of thyroid hormones.
• The net effect of elevated TBG synthesis is to force a new
equilibrium between free and bound thyroid hormones and
thus a significant increase in total T4 and T3 levels.
• The increased demand for thyroid hormones is reached by
about 20 weeks of gestation and persists until term.
Notes:
• Prolactin (hPRL)
• Prolactin is a pituitary hormone essential for
initiating and maintaining lactation.
• Circadian changes in prolactin concentration
in adults are marked by episodic fluctuation
and a sleep-induced peak in the early morning
hours.