Miscarriage
From Encyclopedia of Sex and Sexuality
Early spontaneous pregnancy loss—miscarriage—is the most common complication of pregnancy. It occurs in approximately 15 percent of clinically confirmed pregnancies, but the very early and often unrecognized pregnancy loss rate is two to three times higher. The incidence increases with the age of the potential mother.
Most miscarriages are due to defects in the developing embryo, such as abnormal cells or chromosomes, defective implantation in the uterus, and perhaps other as yet unrecognized causes. The high proportion of abnormal tissues from miscarried embryos is apparently an indication of a natural selective process that prevents about 95 percent of defective embryos from progressing to birth (see birth defects).
Miscarriages are usually classified to determine appropriate medical treatment. Physicians have long used the medical term “abortion” to describe spontaneous early pregnancy loss, but the word “miscarriage,” commonly used by the public and preferred by patients, is gradually replacing it. However, medical classifications of miscarriage continue to use the word abortion.
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[edit] Threatened Abortion
The possibility of miscarriage is usually indicated by a bloody vaginal discharge or uterine bleeding, usually preceding uterine cramping or low backache. On pelvic examination, the cervix is found to be closed and no tissue has passed. Up to 25 percent of pregnant women have some degree of spotting or bleeding during early pregnancy, but about one-half of them continue to progress to normal deliveries. Fetal heart motion, now detectable by ultrasound from six weeks of pregnancy onward, has made the evaluation of threatened miscarriages more precise. Over 95 percent of pregnancies will continue if fetal life is demonstrated by this technique. The prognosis becomes worse if bleeding and cramping is progressive, hCG (human chorionic gonadotropins) pregnancy hormone levels are falling, or the uterus is not growing in size. There is no convincing evidence that any course of treatment, such as bed rest, avoidance of intercourse, or medications, reverses the course of a threatened abortion, but a sympathetic attitude on the part of the physician is important. Initially, it is wise for the woman to remain at home near a telephone until it can be determined whether the symptoms persist or cease. If clinical evaluation indicates that the embryo is no longer alive, evacuation of the uterus by dilation of the cervix and curettage of the inner lining of the uterus (“D & C”) is performed, or occasionally, a woman will choose to wait for a spontaneous miscarriage.
[edit] Inevitable and Incomplete Abortion
Miscarriage is a process rather than a single event. It is considered inevitable when bleeding or rupture of the membranes is accompanied by pain and dilation of the cervix. The miscarriage is incomplete when the products of conception have only partially passed from the uterine cavity, are protruding from the cervix, or are in the vagina with persistent cramping and bleeding (which can be profuse). A careful vaginal examination can establish the diagnosis. Since no fetal survival is possible with inevitable or incomplete miscarriages, treatment aims at evacuating the uterus to prevent further hemorrhage or infection.
[edit] Complete Abortion
Patients being monitored for threatened miscarriage are instructed to save all tissue passed so that it can be inspected. With a complete miscarriage, pain and bleeding cease soon after all the products of conception have passed. If the diagnosis is certain, no further therapy may be necessary. However, in some circumstances, curettage is required to be sure that the uterus is completely emptied.
[edit] Missed Abortion
In cases of missed abortion, expulsion of the tissues does not occur for a prolonged period of time after embryonic death. Symptoms of pregnancy regress, pregnancy tests become negative, and no fetal heart motion is detected. Although most patients eventually abort spontaneously, waiting for that to occur may be emotionally trying, and many women prefer to have the tissues removed by “D & C.”
[edit] Septic Abortion
Infected (septic) abortion, once a leading cause of maternal death because of the poor clinical conditions under which many illegal abortions were performed, has been less frequent in recent years as liberalized abortion laws have made physician-induced abortions available to women with unwanted pregnancies. Women with septic abortion suffer symptoms of fever, abdominal tenderness, and uterine pain, which in severe cases can progress to overwhelming infection and shock. Therapy consists of aggressive use of antibiotics and evacuation of the uterus, often in an intensive care setting.
[edit] Recurrent Spontaneous Abortion
Recurrent miscarriage is usually defined as three or more consecutive first trimester spontaneous losses. Such miscarriages have received a great deal of attention in both the media and medical literature during the past few years. Diagnosis and treatment of the woman suffering recurrent miscarriage is still one of the most difficult areas in reproductive medicine. Investigation for chromosome abnormalities, uterine anomalies, hormonal deficiencies, and immunological factors are necessary to rule out potential paternal or maternal factors.
One major specific cause of second-trimester (four to six months) pregnancy loss is premature cervical dilation, known medically as incompetent cervix. When this occurs, there is a gradual, painless dilation of the cervix, rupture of membranes, and delivery of a fetus so immature that it almost never survives. Recurrences of incompetent cervix usually can be prevented by a surgical procedure called cerclage, making a purse string-like suture to reinforce the cervix.
Miscarriage is a frustrating problem for both patients and physicians. There is often no good understanding of its causes, and treatment is not always successful. In most cases a miscarriage does not imply that another will occur in the next pregnancy. Nevertheless, the establishment of trust and rapport and appreciation of the distress experienced by these couples permits a thorough discussion between the physician and the couple about treatment of the miscarriage and future pregnancies.
