|
|||||||
|
Uterine Factors In Infertility
Abnormalities of the uterus can have a significant impact on the ability of a woman to conceive and to carry a pregnancy successfully. Some women have an abnormally developed uterus from birth (congenital) while others may develop a uterine problem due to infection or surgery (acquired). A variety of uterine factors can play a significant role in reproductive failure. These factors may contribute to infertility and also to recurrent miscarriage. Even when uterine factors are diagnosed, all other potential factors which might contribute to infertility should be aggressively evaluated and treated. Only when the entire picture is clearly understood and alternatives, risks, and benefits have been thoroughly discussed should a surgical approach be considered. Fertility problems involving the uterus include:
Uterine FibroidsThe uterus is composed primarily of smooth muscle. A leiomyoma, or fibroid, is a benign tumor of this muscle. Fibroids are generally fairly round though they can have a variety of irregular shapes. They range from pea size to the size of a grapefruit or even larger. Frequently, multiple fibroids are present. They can be located within the cavity of the uterus (intracavitary), within the uterine wall (intramural), or on the surface of the uterus (subserosal). The location of the fibroid may have a great deal to do with the symptoms experienced which include pelvic pain, bleeding, heavy and uncomfortable menstrual periods, or pressure on the bladder or rectum. Approximately 40% of women will develop fibroids during their reproductive life, with as many as half having symptoms due to these benign tumors. Fibroids are more common in women whose female relatives had them, and may also be more common in certain ethnic groups. The reason that fibroids begin to grow is unknown. However, it is indisputable that estrogen is required to promote and maintain the growth of fibroids. Therefore, fibroids are rare before puberty, may enlarge during pregnancy or when high levels of estrogen is given, and usually shrink after menopause. The diagnosis of uterine fibroids is generally made at the time of pelvic exam when a woman complains of the common symptoms described, or when a mass is palpated in the abdomen or pelvis. The uterus is usually enlarged and irregular in shape. Fibroids may cause infertility by blocking the cervical area, the tubes, or distorting the uterine cavity. Some theories suggest that the blood supply of the uterus may be disrupted and thereby cause decreased fertility. It is uncommon for fibroids to be the sole cause of infertility. That is to say, all other factors should be fully evaluated before deciding on removal of the fibroids (myomectomy). If all other factors are normal, pregnancy rates are quite good following surgery. Treatment of Uterine Fibroids
Congenital Abnormalities of the UterusBetween weeks 9 and 16 of pregnancy, the tubular systems forming in the fetus called the Müllerian ducts fuse together to form the uterus. If these ducts do not develop normally, congenital abnormalities of the uterus can occur.
The most common congenital uterine anomaly is the septate uterus. While most women with a septate uterus have normal success in conceiving and delivering (though a somewhat higher rate of breech presentation and cesarean section), approximately 1 of 4 women with a septate uterus will have persistent reproductive failure. Generally, these women have problems with repetitive miscarriages more than with infertility. About 80% of these women carry their pregnancies successfully after surgical removal of the septum. Diagnosis The diagnosis of congenital uterine anomalies is made on the basis of clinical suspicion and a hysterosalpingogram (HSG, or uterine x-ray). Magnetic resonance imaging (MRI) has also been used to aid in the diagnosis and clarification of these anomalies, but does not commonly add very much to the HSG results. If a woman with repeated miscarriages has a double uterus as described above it is often assumed that the congenital uterine anomaly is the cause of the problem. However, it is important to exclude any other factor contributing to miscarriage before initiating treatment. Surgical repair should only be considered after a thorough evaluation and an extensive discussion between patient and physician. Treatment Surgical correction of the uterus (metroplasty) is the recommended approach for treatment of the septate or bicornuate uterus.
Asherman's syndrome and AdenomyosisAsherman's Syndrome is defined as the presence of scar tissue in the uterine cavity (intrauterine adhesions). It can be severe, in which case the whole uterine cavity is scarred and the woman does not menstruate, or mild, with only a few bands of scar tissue present. These women may have light periods. Causes of Asherman's Syndrome
Removal of adhesions within the uterus is performed by hysteroscopy. Postoperatively, a high dose of estrogen may be prescribed and/or an IUD may be inserted to help prevent the uterine walls from healing together. For mild to moderate adhesions, there is a 60-80% chance of successful pregnancy after repair.
AdenomyosisAdenomyosis is the growth of glands from the endometrium into the muscle wall of the uterus. This condition can lead to excessive menstrual bleeding and pain. Treatment of Adenomyosis is similar to that for endometriosis and may involve the use or drugs such as GnRH agonists, danazol or birth control pills.
DES ExposureDiethylstilbestrol (DES) is a synthetic hormone which was given to pregnant women for approximately 20 years, until the late 1960's, primarily to prevent miscarriage. Unfortunately, data eventually showed that DES did not prevent miscarriage but did cause a number of embryological abnormalities in the children of women who took DES during their pregnancy. The primary uterine abnormality seen in DES exposed women is a small, irregularly shaped cavity which may be constricted in certain areas and T-shaped. Other reproductive difficulties associated with a DES exposed uterus include high risk for: hypoplastic uterus (underdeveloped), irregular uterine lining, ectopic pregnancy, premature labor, or incompetent cervix which may result in painless cervical dilatation and premature delivery. The diagnosis of the DES exposed uterus is made by hysterogram. While one small study has suggested that surgical treatment of the DES-exposed uterus may improve the reproductive outcome of women with this abnormality, others have not found this to be the case and it is generally felt that surgical treatment for this type of uterine abnormality is not effective. DES exposure in utero can also affect males. Studies have shown that DES men may have an abnormal semen analysis.
The Eye and How It Works
|
