Understanding Pregnancy Loss

Uterine Anomalies
Abnormalities in the shape of the uterus must be excluded. When the uterus is abnormal, the chances of miscarriage are significantly increased. Much of this is probably due to the fact that there is not a good blood supply to the abnormal uterine tissue. If the placenta begins to grow on this tissue, it cannot get the blood supply it needs to survive. Uterine anomalies can be diagnosed by a hysterosalpingogram or hysteroscopy. Surgical correction of a uterine abnormality dramatically improves the chances of a successful pregnancy.

Another type of anatomic problem that can result in recurrent loss is an incompetent cervix. It is the responsibility of the cervix to stay shut and hold the pregnancy in the uterus until it is time to deliver. In some individuals, the cervix just does not form quite properly, and in others it malfunctions as a result of prior surgery or manipulation. An incompetent cervix usually presents with a relatively painless dilation of the cervix and premature delivery in the second trimester. An incompetent cervix can be diagnosed by history, X-ray, and other simple procedures.

Autoimmune Disorders
For reasons that are not clear, certain women can begin to produce antibodies to substances in their own bodies. One group of these antibodies are called antiphospholipid antibodies. The two most important of these antibodies are anticardiolipin and lupus anticoagulant. The presence of these antibodies is a well-recognized cause of pregnancy loss. These antibodies can be detected by blood tests. Treatment with low-dose aspirin (one baby aspirin a day) and heparin is the preferred treatment. At times, steroids may have to be added to the treatment, but the risk of side effects increases dramatically if steroids are used.

Endocrinologic Disorders
Certain disorders, such as thyroid disease or diabetes, may be associated with recurrent loss. Although other symptoms will usually be present to suggest these processes, it is worthwhile at least to check a thyroid-stimulating hormone (TSH) level to be sure the thyroid is normal.

Cycle Abnormalities
There is some evidence that individuals who have luteal phase insufficiency have an increased incidence of recurrent loss. This is certainly not to say that endometrial biopsies should be performed to evaluate this. Don't have repeated endometrial biopsies. But progesterone levels should be checked and the luteal phase evaluated. Progesterone suppositories or certain ovulation induction medications can be used to improve progesterone levels and the luteal phase.

Alloimmune Disorders
In order for a pregnancy to survive, the female's immune system must recognize it as a foreign body, that is, one that is at least partially derived from someone else's genes. In pregnancy, this recognition results in the production of what are called "blocking antibodies." Blocking antibodies function to prevent the rejection of the pregnancy by the rest of the immune system. In some couples, the male's immune system may be similar enough to the female's immune system that her system does not really recognize the pregnancy as foreign, and therefore does not produce adequate blocking antibodies. Without blocking antibodies, the rest of the immune system can attack the pregnancy and cause it to fail.

This problem is evaluated through blood testing which is rather expensive. Treatment involves injecting white blood cells from the husband into the wife so that her immune system will begin to recognize his cells as foreign and begin to respond appropriately. Although some centers have reported excellent results with this form of therapy, this is certainly the most controversial of any of the causes of recurrent pregnancy loss and should be discussed carefully with your physician.