Frequent Miscarriages

The miscarriage rate of women in their early 30s is approximately 16 or 17 percent. Most miscarriages are due to abnormalities of the fertilized egg so that the pregnancy stops developing at some point after implantation. This development may stop within a few days following implantation or following several weeks after implantation. The miscarriage rate is increased as women get older. In women over the age of 40, the chance of having a miscarriage is between 30-50 percent. Women who are younger and get pregnant in their early 20s have miscarriage rates that are closer to 10 percent. The classic definition of recurrent pregnancy loss is three or more miscarriages in a row. This occurs in about 1 percent of the general population. Some causes of recurrent pregnancy loss include abnormalities of the uterus itself. These abnormalities can be evaluated through either a special ultrasound test or an x-ray test called a hysterosalpingogram. Another cause of recurrent pregnancy loss is a condition called a balanced translocation. This is a situation in which either the mother or father does not carry the normal 23 pairs of chromosomes. Instead, they may have chromosomes that are attached to each other in such a way that when they separate to form a sperm or an egg, there is either too little or too much chromosomal information. When the sperm or egg fertilizes the resulting embryo does not have the normal amount of chromosomal or genetic material. This balanced translocation situation occurs in about 3 percent of couples who suffer from recurrent pregnancy loss. A much less common cause of recurrent pregnancy loss is a syndrome called antiphospholipid antibody syndrome. In this condition, there is an elevation in antiphospholipid antibodies or the presence of lupus anticoagulant. It is believed that women who have this condition may form blood clots within the placenta interrupting the blood supply to the embryo resulting in pregnancy loss. Individuals with this condition generally have miscarriages that occur later in the pregnancy. Unfortunately, many couples that have recurrent pregnancy loss do not have an identifiable cause explaining their losses. Fortunately, women who have had three miscarriages in a row and have never had a delivery of a baby, have a 50 or 60 percent chance of having a live birth with their fourth pregnancy. If women have delivered a baby and then have had three miscarriages, they have a 75 percent chance of delivering a healthy infant with their fifth pregnancy.