Female Factor Infertility
Peritoneal factors refer to any factors (other than those involving specifically the ovaries, fallopian tubes, or uterus) within the abdomen of the female partner that may be interfering with her fertility. Two such problems include pelvic adhesions and endometriosis.
Pelvic adhesions are thick, fibrous scars. These scars can be the result of past infections, particularly sexually transmitted diseases such as PID, or infections following abortions or prior births. Previous surgeries can also leave behind scarring. Complications from appendicitis and certain intestinal diseases can also result in adhesions in the pelvic area.
Endometriosis also results in pelvic adhesions. Endometriosis is the abnormal location of uterine tissue outside of the uterus. When uterine tissue is planted elsewhere in the pelvis, it still bleeds on a monthly basis with the start of the normal menstrual period. This leads to irritation within the pelvis around the site of this abnormal tissue and bleeding, and ultimately causes scarring.
Pelvic adhesions contribute to infertility primarily by obstructing the fallopian tubes. The ovum may be prevented from traveling down the fallopian tube from the ovary, and the sperm prevented from traveling up the fallopian tube from the uterus; or the blastocyst may be prevented from entering into the uterus where it needs to implant. Scarring can be diagnosed by examining the pelvic area with a scope, which can be inserted into the abdomen through a tiny incision made near the naval. This scoping technique is called laparoscopy.
Obstruction of the fallopian tubes can also be diagnosed by observing through x ray exam whether dye material can travel through the patient's fallopian tubes. Interestingly enough, this procedure has some actual treatment benefits for the patient, as a significant number of patients become pregnant following this x ray exam. It is thought that the dye material in some way helps clean out the tubes, decreasing any existing obstruction.
Pelvic adhesions can be treated using the same laparoscopy technique utilized in the diagnosis of the problem. For treatment, use of the laparoscope to visualize adhesions is combined with use of a laser to disintegrate those adhesions. Endometriosis can be treated with certain medications, but may also require surgery to repair any obstruction caused by adhesions.
Uterine factors contributing to infertility include tumors or abnormal growths within the uterus, chronic infection and inflammation of the uterus, abnormal structure of the uterus, and a variety of endocrine problems (problems with the secretion of certain hormones), which prevent the uterus from developing the thick lining necessary for implantation by a blastocyst.
Tubal factors are often the result of previous infections that have left scar tissue. This scar tissue blocks the tubes, preventing the ovum from being fertilized by the sperm. Scar tissue may also be present within the fallopian tubes due to the improper implantation of a previous pregnancy within the tube, instead of within the uterus. This is called an ectopic pregnancy. Ectopic pregnancies cause rupture of the tube, which is a medical emergency requiring surgery, and results in scarring within the affected tube.
X-ray studies utilizing dyes can help outline the structure of the uterus, revealing certain abnormalities. Ultrasound examination and hysteroscopy (in which a thin, wand-like camera is inserted through the cervix into the uterus) can further reveal abnormalities within the uterus. Biopsy (removing a tissue sample for microscopic examination) of the lining of the uterus (the endometrium) can help in the evaluation of endocrine problems affecting fertility.
Treatment of these uterine factors involves antibiotic treatment of any infectious cause, surgical removal of certain growths within the uterus, surgical reconstruction of the abnormally formed uterus, and medical treatment of any endocrine disorders discovered. Progesterone, for example, can be taken to improve the hospitality of the endometrium toward the arriving blastocyst. Very severe scarring of the fallopian tubes may require surgical reconstruction of all or part of the scarred tube.
Ovulatory factors are those factors that prevent the maturation and release of the ovum from the ovary with the usual monthly regularity. Ovulatory factors include a host of endocrine abnormalities, in which appropriate levels of the various hormones that influence ovulation are not produced. Numerous hormones produced by multiple organ systems interact to bring about normal ovulation. Therefore, ovulation difficulties can stem from problems with the ovaries, the adrenal glands, the pituitary gland, the hypothalamus, or the thyroid.
The first step in diagnosing ovulatory factors is to verify whether or not an ovum is being produced. Although the only certain proof of ovulation (short of an achieved pregnancy) is actual visualization of an ovum, certain procedures suggest that ovulation is or is not taking place.
The basal body temperature is the body temperature that occurs after a normal night's sleep and before any activity (including rising from bed) has been initiated. This temperature has normal variations over the course of the monthly ovulatory cycle, and when a woman carefully measures and records these temperatures, a chart can be drawn that suggests whether or not ovulation has occurred.
Another method for predicting ovulation involves measurement of a particular chemical that should appear in the urine just prior to ovulation. Endometrial biopsy will reveal different characteristics depending on the ovulatory status of the patient, as will examination of the mucus found in the cervix (the opening to the uterus). Also, pelvic ultrasound can visualize developing follicles (clusters of cells that encase a developing ovum) within the ovaries.
Treatment of ovulatory factors involves treatment of the specific organ system responsible for ovulatory failure (for example, thyroid medication must be given in the case of an underactive thyroid, a pituitary tumor may need removal, or the woman may need to cease excessive exercise, which can result in improper activity of the hypothalamus). If ovulation is still not occurring after these types of measures have been taken, certain drugs exist that can induce ovulation. These include Clomid, Pergonal, Metrodin, Fertinex, Follistim, and Gonal F. These drugs, however, may cause the ovulation of more than one ovum per cycle, which is responsible for the increase in multiple births (twins, triplets, etc.) noted since these drugs became available to treat infertility.
The cervix is the opening from the vagina into the uterus through which the sperm must pass. Mucus produced by the cervix helps to transport the sperm into the uterus. Injury to the cervix during a prior birth, surgery on the cervix due to a pre-cancerous or cancerous condition, or scarring of the cervix after infection, can all result in a smaller than normal cervical opening, making it difficult for the sperm to enter. Furthermore, any of the above conditions can also decrease the number of mucus-producing glands in the cervix, leading to a decrease in the quantity of cervical mucus. In other situations, the mucus produced is the wrong consistency (perhaps too thick) to allow sperm to travel through. Certain infections can also serve to make the cervical mucus environment unfavorable to the transport of sperm, or even directly toxic to the sperm themselves (causing sperm death). Some women produce antibodies (immune cells) that identify sperm as foreign invaders.
The qualities of the cervical mucus can be examined under a microscope to diagnose cervical factors as contributing to infertility. The interaction of a live sperm sample from the male partner and a sample of cervical mucus can also be examined.
Treatment of cervical factors includes antibiotics in the case of an infection, steroids to decrease production of anti-sperm antibodies, and artificial insemination techniques to completely bypass the cervical mucus.
Assisted reproduction comprises those techniques that perhaps receive the most publicity as infertility treatments. These include in vitro fertilization (IVF), gamete intrafallopian tube transfer (GIFT), and zygote intrafallopian tube transfer (ZIFT). All of these are used after other techniques to treat infertility have failed.
IVF involves the use of a drug to induce multiple ovum production, and retrieval of those ova either surgically or by ultrasound-guided needle aspiration through the vaginal wall. Meanwhile, multiple semen samples are obtained from the male partner, and a sperm concentrate is prepared. The ova and sperm are then cultured together in a laboratory, where hopefully several of the ova are fertilized. Cell division is allowed to take place up to either the pre-embryo or blastocyst state. While this takes place, the female may be given medication to prepare her uterus to receive an embryo. When necessary, a small opening is made in the outer shell (zona pellucida) of the pre-embryo or blastocyst by a process known as assisted hatching. Two or more pre-embryos or two blastocysts are transferred into the uterus, and the wait begins to see if any or all of them implant and result in an actual pregnancy.
The national average success rate of IVF is 27%, but some centers have higher pregnancy rates. Transferring blastocysts leads to a pregnancy rate of up to 50% or higher. Interestingly, the rate of birth defects resulting from IVF is lower than that resulting from unassisted pregnancies. Of course, because most IVF procedures place more than one embryo into the uterus, the chance for a multiple birth (twins or more) is greatly increased.
GIFT involves retrieval of both multiple ova and semen, and the mechanical placement of both within the fallopian tubes, where fertilization may occur. ZIFT involves the same retrieval of ova and semen, and fertilization and growth in the laboratory up to the zygote stage, at which point the zygotes are placed in the fallopian tubes. Both GIFT and ZIFT seem to have higher success rates than IVF.
Ova can now be frozen for later use, although greater success is obtained with fresh ova. However, storing ova may provide the opportunity for future pregnancy in women with premature ovarian failure or pelvic disease or those undergoing cancer treatment.
Any of these methods of assisted reproduction can utilize donor sperm and/or ova. There have even been cases in which the female partner's uterus is unable to support a pregnancy, so the embryo or zygote resulting from fertilization of the female partner's ovum with the male partner's sperm is transferred into another woman, where the pregnancy progresses to birth.
Chances at pregnancy can be improved when the pre-embryos are screened for chromosomal abnormalities and only the normal ones are transferred into the uterus. This method is useful for couples who are at an increased risk of producing embryos with chromosomal abnormalities, such as advanced maternal age or when one or both partners carry a fatal genetic disease.
Multiple ethical issues have presented themselves as a result of assisted reproduction. Some of these issues involve the use of donor sperm or ova, and surrogate motherhood. Other issues include what to do with frozen embryos, particularly when the couple has divorced.
A particularly difficult ethical problem has come about by virtue of the technique of transferring multiple embryos or zygotes into the female. When pregnancy occurs in which there are multiple developing fetuses, there is a greatly increased chance for pregnancy complications, preterm delivery, and life-long medical problems. Techniques allowing only one or two of the fetuses to continue developing may be employed.
See also Reproductive system.
The Merck Manual of Diagnosis and Therapy. 17th ed, edited by Mark H. Beers and Robert Berkow. Whitehouse Station, NJ: Merck Research Laboratories, 1999.
Speroff, Leon. Clinical Gynecologic Endocrinology and Infertility. Baltimore: Lippincott Williams & Wilkins, 1999.
Tesarik, Jan, and Carmen Mendoza. "In Vitro Fertilization by Intracytoplasmic Sperm Injection." BioEssays, 21 (1999): 791-801.
Yoshida, Tracey M. "Infertility Update: Use of Assisted Reproductive Technology." Journal of the American Pharmaceutical Association 39 (1999): 65-72.
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