All female infertility patients will
undergo a complete hormone evaluation. Many different
hormones must interact precisely to cause proper ovulation,
implantation of an early pregnancy, and the maintenance
of an ongoing pregnancy.
The pituitary gland is under hormonal
control of the hypothalamus, an endocrine
organ located at the base of the brain. The pituitary
is responsible for the production of FSH, LH, and
other important hormones.
FSH stimulates the recruitment and development
of eggs within the follicles located in the ovaries.
The hormones discussed below are commonly evaluated. Because the menstrual cycle is a cascade of different hormonal events, these hormones are usually measured at a specific time during the ovulatory cycle.
Day 3 FSH, LH, and Estradiol
The level of FSH is controlled
by a complex interaction of several hormones. High
levels of FSH on day 3 of the menstrual cycle may
indicate the onset of menopause.
The injectable FSH
medications given to stimulate ovulation mimic
the bodies natural FSH. Artificially raising FSH levels
with medication (ovulation induction) during the first
part of the ovulatory cycle causes the development
of multiple eggs, which are needed for assisted reproductive
procedures, such as IVF.
FSH should be measured in all women
to exclude pre-menopause. Depending on the laboratory,
an FSH level greater than 10 mIU/ml may be of concern.
In certain patients, a Clomid
challenge test may provide an indication of ovarian
reserve. In the Clomid challenge test, Clomid is administered
in a standardized dose of 100 mg between days five
and nine. FSH and estradiol are measured again on
day 10. This tests the ovaries response when stimulated.
As follicles develop, estrogen levels rise which helps
to stimulate the endometrium (lining of the uterus)
to grow in preparation for receipt of the fertilized
egg. Androgen levels are elevated in conditions such
as polycystic ovarian disease.
LH is responsible for triggering the release of the
egg from the follicle (inducing ovulation).
Thyroid testing is imperative in all women experiencing infertility as detection and correction of a thyroid problem is paramount to facilitating successful conception.
Prolactin is the “milk producing hormone”
secreted by the pituitary gland. Elevated prolactin
levels must be reduced for successful conception to
occur. This condition, known as hyperprolactinemia,
may be caused by hypothyroidism or a benign tumor
in the brain and it responds well to medical
or surgical treatment.
Progesterone, usually measured on day 21 of the cycle,
is an accurate indicator of ovulation. A level above
15 ng/dl is desirable and levels can be compared for
different ovulatory cycles. Progesterone
is also necessary to support the developing fetus.
Initially it is produced by the corpus luteum (the
follicular structure remaining after ovulation) and
later by the placenta.
Male hormones such as DHEAS sulfate, testosterone,
17-hydroxyprogesterone, and cortisol may be measured
in some patients. Elevated androgens may indicate
the presence of PCOS.
B-hCG (the hormone of pregnancy) is measured to document pregnancy. The initial rise and precipitous fall of this hormone may indicate early pregnancy loss.
The premenopausal ovary looses its ability to secrete the hormone inhibin, which is part of the negative feedback loop. Assay of this hormone may be valuable in assessing ovarian function in older women. Anti Mullerian hormone is another marker of ovarian reserve.