by Jason G. Bromer, MD
Are miscarriages considered a fertility issue?
It is a common misconception that women who have miscarriages are just fine because they “can get pregnant.” In fact, having multiple miscarriages is a very specific type of fertility problem that affects 1-3% of all couples.
Why exactly and how many miscarriages are considered a fertility issue?
A key part of the definition of infertility is being able to achieve a successful pregnancy, meaning delivering a healthy child. Pregnancies that result in miscarriages may not always signal an underlying fertility issue, but sometimes they do. Recurrent pregnancy loss (RPL) is defined as having two or more miscarriages consecutively. In some cases, fertility specialists will start looking for underlying causes after just one loss.
What are the factors that can cause miscarriage?
The majority of miscarriages are due to genetic abnormalities in the embryo, which can be either spontaneous or acquired from one of the parents in the case of a chromosomal translocation. Other causes include hormonal problems like diabetes, hyperprolactinemia, and thyroid disease, structural problems in the uterus like a uterine septum or scar tissue, and certain acquired blood clotting disorders like the anti-phospholipid syndrome.
Does age play a part in miscarriage?
Age definitely plays a role in the risk of miscarriage. As women age, the percentage of genetically normal eggs they have decreases significantly. In fact, by the age of 43, over 90% of the remaining eggs in the ovaries are abnormal, and the risk of miscarriage exceeds 50% in each pregnancy. It is important to note, however, that the age of the uterus does not have the same impact, such that age related miscarriages can often be treated through use of a donor egg.
What, if anything, can be done to limit risk of miscarriage?
The treatment for recurrent miscarriages depends on the underlying cause.
- Hormonal problems can and should be treated prior to trying to conceive again and progesterone support is frequently helpful.
- Uterine problems can often be treated with a very minor surgical procedure called a hysteroscopy.
- Blood clotting disorders can be overcome by using blood thinners like aspirin or heparin.
- Genetic abnormalities can sometimes by prevented with in vitro fertilization in conjunction with a procedure called pre-implantation genetic diagnosis. This procedure involves removing one or more cells from an embryo to test the genetic make-up of the whole embryo prior to placing it back in the mother’s uterus. This way, we can assure that only genetically normal embryos have a chance to implant.