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Endometriosis Awareness: How It Affects Fertility
by Leigh Ann Woodruff, March 28, 2012
While not all women with endometriosis are infertile, about 30 percent to 40 percent of women with are, which makes endometriosis one the top causes of female infertility.
Some women don't even find out they have endometriosis until they have trouble getting pregnant. "Some women with infertility, who are later found to have endometriosis, have not had any other symptoms of endometriosis," says Carol Drury, Education Program Coordinator and Associate Director of the Endometriosis Association, "though some experience symptoms later."
Researchers are actively studying the relationship between endometriosis and infertility, and there are many different ways endometriosis is thought to have an effect — from lesions that distort pelvic anatomy to immunological abnormalities.
"It appears that any stage of endometriosis, even mild, can negatively affect a woman's fertility for a variety of reasons," says Laurence Jacobs, M.D., a fertility doctor with Fertility Centers of Illinois. "When compared with normally ovulating women of a similar age who do not have endometriosis, women with mild to moderate endometriosis are about three to four times less likely to have a successful pregnancy."
Endometrial lesions may distort pelvic anatomy and interfere with the normal function of the fallopian tubes, which is to transport the fertilized egg to the uterus, where it will implant.
"With this type of problem, the degree of infertility is proportional to the severity of the endometriosis and adhesions," Dr. Jacobs says. "This type of infertility can often be overcome with surgery and/or a fertility treatment such as intrauterine insemination (IUI)."
Having multiple surgeries for endometriosis may also increase the risk for infertility. "Multiple pelvic surgeries, such as those done to remove endometrial lesions, can put a woman at greater risk for developing adhesions — bands of scar tissue — which can cause anatomical programs such as blocked fallopian tubes," Drury says.
Diminished Ovarian Reserve
Women with advanced stages of endometriosis tend to have large ovarian cysts (endometriomas) and severe pelvic adhesions. "Large, invasive endometriomas may destroy much of the normal ovarian tissue," Dr. Jacobs says. "And women with these advanced stages of endometriosis have often had multiple extensive surgeries due to chronic pelvic pain."
These multiple ovarian surgeries are not good for fertility. "Surgery on the ovaries, a common site for endo, can compromise the blood supply to the ovaries or reduce the volume of ovarian tissue," Drury says. This can lead to a reduction in the number of eggs remaining, as well as decreased ovarian blood flow due to adhesions following surgeries.
"If an infertility patient has endometriomas that are not symptomatic, we will leave them alone so as to not compromise their ovarian reserve of eggs, in anticipation of doing IVF," Dr. Jacobs says.
Toxic Pelvic Environment
Tissue damage from endometriosis may trigger inflammatory reactions in the peritoneal environment — the fluid in the space between the layers of tissue that line the belly's wall and the abdominal organs. The endometriosis creates an increased volume of fluid in the pelvis, and, therefore, an increased amount of substances that may create an environment that impairs egg, sperm, embryo and fallopian tube functions.
"This inflammatory reaction in the pelvis may result in the production and release of 'toxic substances' and activation of specific white blood cells that may interfere with fertilization of eggs as the eggs pass through the pelvis from the ovary into the fallopian tube," Dr. Jacobs says. "In addition to the eggs being exposed to inflammatory cells and toxins, sperm waiting in the tubes may also be affected."
A toxic pelvic environment may explain why pregnancy rates are reduced in women with even the mildest stages of endometriosis. "In vitro fertilization (IVF) may bypass this problem of the toxic pelvic environment by transferring embryos directly into the uterine cavity," Dr. Jacobs says.
Autoimmune Implantation Dysfunction
In some women, endometriosis may cause "autoimmune implantation dysfunction," which means tissue damage from the endometriosis causes the production of antiphospholipid antibodies and the activation of specialized immune cells in the uterine lining known as natural killer (NK) cells and cytotoxic lymphocytes (CTL). The NK/CTL activation results in an environment that is not hospitable for an implanting embryo.
"Some researchers claim that up to one-third of women with endometriosis have these immune barriers to implantation," Dr. Jacobs says. "These women may not be able to conceive with IVF until the underlying autoimmune implantation problem has been identified and treated with immunoptherapy. Women with endometriosis may benefit from an evaluation for immunologic factors, and several reports have demonstrated that women with endometriosis-related autoimmnune implantation failure may benefit from intralipid or IVIG treatments, as well as steroids or Lovenox if adminisstered prior to an IVF embryo transfer."
Women with endometriosis who are trying to get pregnant should consult with Ob/Gyn or fertility doctor about their plans. "For those with endo, preconception planning for the best health possible is highly recommended," Drury says. "Measures should include eating the best possible nutrition, reducing exposure to toxic chemicals, having your thyroid checked, and getting allergies and candida (yeast infections) under control."