The Relationship Between Infertility And Endometriosis
While endometriosis has long been regarded as a risk factor for infertility,
a causal relationship between endometriosis and infertility has not been proven.
What do we know for sure about the connection between endometriosis and infertility?
We know that there is an increased prevalence of endometriosis in women with
decreased fertility compared with women who have given birth. This extends
beyond a decreased fertility rate by "natural" conception. Even though the
fallopian tubes are bypassed with in vitro fertilization (IVF), a reduced implantation
rate per embryo after IVF has also been demonstrated in women with moderate
to severe endometriosis compared with women without endometriosis. In addition,
a relatively increased fertility and pregnancy rate has been demonstrated in
women with mild to moderate endometriosis who have had surgical treatment.
What is it about endometriosis that increases the risk of infertility? There
may be several factors. First, women with moderate to severe endometriosis
often develop pelvic adhesions or scar tissue. This may impair the function
of the fallopian tubes and even the ovaries. There are probably many other
factors which have yet to be identified or confirmed.
Endometriosis may also simply be diagnosed more frequently in women being evaluated
for infertility. It is not known exactly how common endometriosis is in women
in general because it is difficult to diagnose. Estimates are that 8 to 10%
of women of reproductive age may have endometriosis in the United States. Women
with infertility, however, are very likely to have a laparoscopic examination,
making endometriosis relatively easy to diagnose. Several studies have show
that endometriosis can be found in anywhere from 30% to 71% of women being evaluated
for infertility. Of these, the range of women with infertility and moderate
to severe endometriosis was 19% to 43%. In these studies, women who had already
given birth (secondary infertility) were less likely to have endometriosis than
women who had not previously given birth.
Created: 10/30/2003 - Donnica Moore, M.D.
