Why me? Common causes of miscarriage
Early pregnancy loss is unfortunately a common occurrence, affecting 1 in 3 or 1 in 4 women. A very small percentage of women (5%) experience recurrent pregnancy loss (RPL), a condition defined as 2 or more miscarriages. Less than 1% of women experience 3 or more miscarriages. To answer the question of why miscarriages happen, taking a closer look at the common causes of miscarriage can help shed some light.
One of the most common causes of miscarriage is genetic abnormalities
There are normally 46 chromosomes that contain the genes for normal develop-ment. When an embryo has an extra chromosome or one is missing, these genetic abnormalities frequently interfere with the healthy development of the baby, resulting in a miscarriage or serious health disorders. Chromosomal abnormalities occur for unknown reasons in up to 60% of first-trimester miscarriages. As a woman ages, her risk for miscarriage due to genetic abnormalities increases — from 10% to 15% in women younger than 35 years old to more than 50% in women over 40 years old.
Anatomic, medical, environmental and lifestyle factors
Uterine abnormalities, such as a septum, fibroid, polyp, or other problems in or near the uterine cavity as well as untreated medical conditions such as thyroid disease or diabetes can increase the risk of miscarriage. Abnormalities of the immune system and blood-clotting system (thrombophilia) can also cause repeated miscarriages. Smoking, the use of recreational drugs and excessive alcohol intake increase the chances for miscarriage as well.
Testing for miscarriage
Women who experience multiple miscarriages receive a thorough medical evaluation and undergo several tests. Blood tests can often reveal if a woman has medical, immune or blood-clotting disorders. A specialized blood test called karyotyping helps detect a genetic cause of pregnancy loss. Imaging tests are also used to help spot anatomic abnormalities of the uterus.
“Unexplained” is a common cause of miscarriage, but there’s hope
For approximately 20-30% of women, there simply is no explanation for their mis-carriage.
Fortunately, even after several pregnancy losses, women have as much as an80% chance for carrying a full-term pregnancy.
If you’ve suffered several miscarriages and are seeking the expertise and compas-sion of a fertility specialist who can help answer your questions, contact one of our physicians.