|
|
As more women are delaying childbirth
and more baby boomers are reaching midlife, the problem
of diminished ovarian reserve (DOR) is increasing. This
has several major medical consequences including infertility,
decreased bone mass with risk of fracture, abnormal
uterine bleeding from lack of regular ovulation, and
hot flashes. This article will address ovarian reserve
testing and its impact on treating infertility.
How many eggs is a woman born with? A
woman is born with her entire life supply of eggs, approximately
1-2 million. At the time of her first menstrual period,
the number of eggs has diminished to 300,000-400,000.
Each cycle, hundreds of eggs undergo stimulation and
usually only one is released during ovulation; the others
are reabsorbed and are not functional.
At what age is a woman most fertile?
Peak fertility in women occurs before age 30, with a
monthly pregnancy rate of 20-25 percent. This monthly
rate starts to decrease around age 32, but rapidly declines
beginning in the late 30's and into the 40's. Approximately
one in three women experience infertility by age 40,
mainly due to poor egg quality. Egg quality decreases
as a woman ages, resulting in impaired fertilization,
reduced implantation, and increased miscarriage along
with the increased potential for chromosomal abnormalities
of the fetus.
What tests can be used to monitor ovarian
function?
Several tests are available to measure ovarian function.
These include: menstrual cycle day three (CD3) blood
test for follicle stimulating hormone (FSH) and estradiol
levels; transvaginal ultrasound ovarian volume and antral
follicle count (OVFC); and the popular fertility medication
clomiphene citrate can be used in combination with FSH
and estradiol (clomiphene citrate challenge test or
CCCT).
CD3 testing is the simplest screening
assessment, in which. FSH and estradiol levels are both
measured. Blood levels of FSH increase as the number
of eggs a woman has decreases. It is important to measure
both levels because high estradiol levels can lower
the day 3 FSH level. Therefore, getting only the FSH
level may show a "falsely" low level. The
addition of transvaginal ultrasound OVFC on CD3 has
greatly added to the diagnosis of DOR. A low ovarian
volume and/or a combined antral follicle (small normal
ovarian cycsts) count of less then 11 reflect DOR.
CCCT utilizes the common fertility drug
for five days during the menstrual cycle and measures
FSH and estradiol levels. Any baseline elevation in
either of these blood tests is indicative of DOR.
What other tests are used?
Inhibin B is a relatively new blood test that may be
more predictive of DOR though standardized levels are
still being determined.
If the estradiol and or FSH levels are
high one month, but are normal in future cycles, is
there need for concern?
Although FSH and/or estradiol can fluctuate monthly,
a single elevation is predictive of poor ovarian function.
All fertility physicians should be familiar
with these ovarian age tests. Initiation of testing
should begin as a woman nears 33 or has other risk factor
such as cigarette smoking, ovarian or extensive pelvic
surgery, a family history of early menopause, or signs
of premature ovarian failure. A well-informed patient
can contribute to her care and this testing may expedite
fertility treatment in her goal of a healthy child.
Mark P. Trolice, M.D., FACOG, FACS
is Director of Fertility C.A.R.E. (Center of Assisted
Reproduction & Endocrinology in the Orlando, Florida
area and Director of Reproductive Endocrinology &
Infertility at Arnold Palmer Hospital for Children &
Women.
|
|
|
