What is a miscarriage?
A miscarriage or spontaneous abortion is the loss of a pregnancy before 20 weeks and it is among the most common complications associated with pregnancy. Estimates show that about 2 in 3 pregnancies end in a miscarriage, most before the woman even realizes that she is pregnant, before the missed period. About ½ of early miscarriages are due to chromosomal abnormalities, mostly due to an abnormal number of chromosomes. The majority of abnormalities are so-called trisomies, followed by monosomy X, triploidy, and tetraploidy.
What are the chances of having a miscarriage and what can cause it?
A recurrent miscarriage has been defined as the occurrence of three or more clinically recognized pregnancy losses before 20 weeks of the pregnancy. Some physicians start a workup for recurrent miscarriage after two losses, particularly if there has been cardiac activity initially. After one miscarriage your chances of having a normal baby are about 76 percent, after 2 miscarriages it’s 70 percent, after 3 it’s 65 percent, and after four miscarriages a live birth can be anticipated in about 60 percent of pregnancies.
Causes of recurrent miscarriages:
- Thyroid disorders
- Immunologic factors
- Genetic abnormalities
- Endocrine disorders
- Diabetes mellitus
- Acquired anatomic abnormalities
- Uterine synechiae
- Cervical incompetence
- Congenital anatomic abnormalities
Evaluation for these abnormalities usually begins after two or three miscarriages. If there was a reason found for the recurrent miscarriage then you can anticipate a successful outcome in 70 to 90 percent of cases. In the case of genetic abnormalities, live births can be anticipated in 20 to 80 percent of cases depending on the genetic condition and the inheritance patterns. When no diagnosis can be made, general supportive care of the early conception yields 40 to 90 percent live birth rates.