10 to 25 percent of all pregnancies end in miscarriage. The reasons for miscarriage in first trimester pregnancies in up to 70 percent of reported cases are thought to occur due to chromosomal abnormalities involving either the sperm, the egg, or both.
Miscarriage is the term given for any pregnancy that ends on its own within 20 weeks of gestation. A lot of women who have miscarriages end up emotional and distraught over losing a fetus and think that they may have done something wrong to cause this problem. Besides the mentioned chromosomal anomalies, other causes of first trimester miscarriages include exposure to environmental factors or industrial toxins or infections. Maternal diabetes, thyroid dysfunction, or other autoimmune conditions may also be involved in causing miscarriages. Very rarely, certain diagnostic procedures may cause a miscarriage such as performing an amniocentesis, where a needle is inserted into the womb to extract amniotic fluid that surrounds the fetus in its amniotic sac. Trauma from injuries or motor vehicle accidents and the use of substances, drugs, or tobacco products may be to blame in some cases.
The number of first trimester miscarriages may even be higher than the reported cases though. The reason for this being that some women may experience what is referred to as a chemical pregnancy, where a pregnancy is lost soon after implantation of a fertilized egg onto the lining of the uterus. The result is bleeding around the time the expected period should occur, thereby not making the affected women realize that she may have conceived.
What happens after a miscarriage?
After a miscarriage, the vaginal bleeding will decrease over a period of a few days. There are times though that one can experience complications from a miscarriage such as an infection. Signs such as a foul-smelling discharge, persistent or increased bleeding, fever, or continuous or worsening lower abdominal cramping warrant further evaluation by a healthcare professional.
Multiple first trimester miscarriages
Most miscarriages are random events that are not likely to recur, but there are women who experience multiple first trimester miscarriages. These women are then assessed and investigated for possible causes to these multiple miscarriages and are managed accordingly. In cases where causes of these miscarriages are not found, it is then assumed that chromosomal issues affecting the embryo may be the reason behind this problem.
This is where Array Comparative Genomic Hybridization (aCGH) testing of fertilized embryos comes into play. This investigation is the latest testing method used to identify any chromosomal abnormalities in embryos. aCGH then allows doctors to select healthier embryos, or at least those without any visible chromosomal abnormalities. These normal embryos are then used to perform in vitro fertilization (IVF).
The advantages of making use of aCGH evaluation of embryos include:
- Improved pregnancy success rates and therefore a highly reduced risk of experiencing another miscarriage
- Fewer embryos need to be transferred because they have been evaluated
- Decreased chance of having multiple births
- Reduced risk of the fetus having birth defects