Miscarriage is one of the most disappointing and painful events that couples have to deal with. This is especially true if pregnancy was achieved after extensive fertility therapies end in miscarriage. Recurrent miscarriage is defined as the loss of two or more consecutive pregnancies.
Approximately 15-20% of pregnancies end in miscarriage and the rate increases as women age. Couples experiencing miscarriage should seek the care of a reproductive endocrinologist, fertility specialist.
The causes of miscarriage can be divided into three categories including anatomic abnormalities of the uterus, hormonal disorders, and genetic abnormalities in the developing embryo – this category is responsible for 60% of all early miscarriages.
Sometimes uterine polyps and/or fibroids can cause miscarriage and they should be evaluated, and possibly removed before pregnancy is attempted. Women may also have other structural uterine abnormalities most of which can be corrected surgically. The hysterosalpingogram and hysteroscope are instruments used to diagnose uterine structural abnormalities. Where there are severe abnormalities, the only option may be to use a surrogate mother to carry the baby to term and delivery.
The uterus may also have damage resulting from severe pelvic infections, known as pelvic inflammatory disease, or PID. PID infections are often “silent”, meaning the damage is caused without the woman having been aware she had an infection. Uterine and tubal damage are often the result of these infections.
Chromosome abnormalities in the fetus are a major cause of miscarriage. In some cases, miscarriage is nature’s way of preventing the birth of a child that will be severely debilitated due to genetic disease. The most common genetic abnormalities are errors in the number of chromosomes, a condition known as aneuploidy. Trisomy, or one extra chromosome, seen in early miscarriages include Trisomy 13, Trisomy 18, and Trisomy 21 (Down syndrome). There can also be abnormalities of the X and Y sex chromosomes. As women age, the incidence of miscarriage increases due to chromosomal errors in the eggs. Fortunately, using preimplantation genetic diagnosis (PGD), it is now possible to diagnose several of these conditions in the embryo prior to transfer to the uterus.
There may also be hormonal causes in the mother, such as progesterone insufficiency, or blood clotting disorders that can impair the development of the placenta. A woman may also have antibodies to phospholipids which comprise a vital part of cell membranes. When antiphospholipid antibodies are present, the placenta does not develop properly and miscarriage can result. Blood tests are available to determine if these conditions exist.
One hope for couples experiencing recurrent miscarriage, when the condition is due to genetic abnormalities, is preimplantation genetic diagnosis. Using PGD in conjunction with an IVF cycle, embryos can be screened for certain specific genetic diseases. Only embryos free of the defect are transferred to the mother’s uterus.
Our physicians will discuss all miscarriage treatment options with affected couples.