Female
Athletes Should Be Aware of Amenorrhea
by
Ginny Ryan, M.D.
University
of Iowa Health Science Relations
Fellow in Reproductive Endocrinology and Infertility
December 2004
It is not uncommon
for athletes to suffer such ailments as stress
fractures, runner's knee, bunions and blisters. But
female athletes face the additional problem of
amenorrhea--loss of menstrual periods, says a
University of Iowa endocrinology specialist.
"It is not
unusual for women engaged in heavy exercise or
competitive sports to have amenorrhea," says
Dr. Ginny Ryan M.D., a fellow in reproductive
endocrinology at the University of Iowa Hospitals
and Clinics. "Amenorrhea can be triggered by
weight loss, disordered eating and stress, all of
which are common among women athletes."
Research indicates
that athletes who participate in endurance sports,
such as swimming and running, and aesthetic sports,
such as gymnastics and ballet, have a higher
incidence of amenorrhea. But athletes with
amenorrhea have been reported in all sports,
including competitive power lifting, Dr. Ryan says.
The number of women
engaged in competitive sports has increased
dramatically in the last few decades, and their
training programs have more intensity and volume
than ever before. In addition, a particular body
shape is often expected in a given sport for
performance or aesthetic reasons, according to Dr.
Ryan.
The result is that
many of these athletes are chronically energy
deficient. "This means that the fuel they take
in does not have enough calories or nutrients to
meet their body's needs. Energy deficiency can lead
to problems with athletic performance, growth, and
health including reproductive health," she
says.
Amenorrhea results
when the brain receives signals saying the body is
in an energy deficient state. The brain then
temporarily slows down or shuts off the reproductive
axis, leading to fertility problems and irregular or
absent periods. "When the reproductive axis is
on hold like this, there is also a decrease in
estrogen production. This can lead to reduced bone
growth and osteoporosis," Dr. Ryan says.
Surprisingly,
psychological stress seems to have little effect on
the development of amenorrhea in athletic women, Dr.
Ryan notes. Studies show there are no measurable
differences in psychological stress tests between
high-intensity athletes with regular cycles and
those with amenorrhea.
However, medical
studies have shown that physical stress plays a role
in the development of amenorrhea, she says.
"The athlete who runs or swims longer, more
often, and with more intensity, is more likely to
develop amenorrhea."
Studies show that in
women who run 10-20 miles a week, only 10-15 percent
have amenorrhea. But when the mileage is increased
to 60 miles a week, 20-30 percent of the athletes
suffer amenorrhea. Dr. Ryan adds that in women
weighing 125-130 pounds, not many have amenorrhea,
but in those weighing about 102 pounds, 60 percent
are amenorrheic. "This shows the combined
training intensity and energy balance," she
notes.
If women athletes
have skipped their monthly menstrual periods, they
should consult a physician. A physical exam and
laboratory evaluation are recommended to confirm a
suspected diagnosis of amenorrhea and rule out other
causes of amenorrhea.
One of the treatment
options for amenorrhea in women athletes includes
weight gain and a reduction in physical training.
"But since these suggestions tend to be
unrealistic for most competitive athletes,
physicians must determine if the amenorrheic
condition or 'low estrogen state' is causing them
harm," Dr. Ryan says. Reproductive function may
improve with small improvements in diet and minimal
change in exercise regimen.
Preliminary research
has suggested that these patients have decreased
bone mass, also known as osteoporosis. This
condition can lead to stress fractures. Estrogen
replacement therapy may be recommended for some
patients, Dr. Ryan notes. Often in the form of oral
contraceptive pills.
Women athletes who
have amenorrhea and wish to become pregnant may
require fertility drugs to induce ovulation.
However, amenorrhea should not be considered a form
of contraception, Dr. Ryan warns. Women with
amenorrhea may ovulate at any time.
BACK |