Causes of Miscarriage

Without any assisted reproduction, the average 30 year old woman will have approximately a 20% chance of becoming pregnant with each menstrual cycle. Of those couples that have a successful fertilization, 15-20% will have a miscarriage before they reach 20 weeks, with risk of miscarriage  increasing with age.

Even with a high incidence of miscarriage, it often leaves a woman with feelings of frustration and many questions of wonder in its wake. What is less common is women that experience two or more miscarriages – otherwise known as recurrent pregnancy loss. If you have experienced two or more miscarriages, it is recommended you speak with a fertility specialist to review your options and how to limit any future miscarriages.

What are the causes of miscarriage?

There are several causes of miscarriage, but in about 50% of cases the cause is unexplained. This is disappointing for patients who have experienced the loss, but the good news is that 70-75% of those with unexplained causes will go on and successfully carry their next pregnancy to full term.

In approximately 45% of cases, the cause of miscarriages is genetic, including aneuploidy or other chromosomal anomalies. Aneuploidy (abnormal number of chromosomes) is a random event that increases with age. Aneuploidy accounts for a large portion of the genetic causes of miscarriage particularly with increasing maternal age, but is attributable to a chance event rather than a cause that will certainly repeat itself.

Pregenetic screening (PGS) can be used to determine what, if any, genetic abnormalities are present. During this screening, the chromosomes are examined to determine a normal copy number. Your physician can then create the best treatment plan for you to increase the chances of having a successful pregnancy.

The remaining causes of miscarriages are split evenly between immunological and anatomical. When the mother’s immune system responds inappropriately to a developing pregnancy, that is considered immunological. There are several factors that may lead to a immunological miscarriage, some of which are treatable.

Anatomical causes deal with the physical structure of the reproductive system and can range from a subtle abnormal uterus shape to the presence of two uteruses and everything in between. Knowing the specific anatomy allows treatment to be appropriately tailored.

If you have experienced miscarriage and would like more information or to schedule an appointment with one of our physicians, please speak with one of our New Patient Liaisons by calling 877-971-7755.
Medical Contribution by Joseph Doyle, MD