Although most couples are blissfully unacquainted with the statistics surrounding miscarriage, pregnancy loss is actually quite common, with 10-25% of recognized pregnancies ending in miscarriage. When you have suffered a pregnancy loss or are in the process of having a miscarriage, you could be wondering what caused the loss and worry about whether it’ll happen again. This short article aims to answer the next questions:

What causes miscarriage?
How common is pregnancy loss?
What type of genetic testing can be acquired for miscarriage tissue?
How do chromosome testing help?
Causes of Miscarriage

There are many different reasons why miscarriage occurs, but the most typical cause for first trimester miscarriage is really a chromosome abnormality. Chromosome abnormalities – extra or missing whole chromosomes, also called “aneuploidy” – occur because of a mis-division of the chromosomes in the egg or sperm involved in a conception. Typically, humans have 46 chromosomes that come in 23 pairs (22 pairs numbered from 1 to 22 and then the sex chromosomes, X and Y). For a child to develop normally it is necessary that it have exactly the right amount of chromosome material; missing or extra material at the time of conception or within an embryo or fetus could cause a female to either not get pregnant, miscarry, or have a child with a chromosome syndrome such as Down syndrome.

Over 50% of most first trimester miscarriages are due to chromosome abnormalities. This number could be closer to 75% or more for women aged 35 years and over who’ve experienced recurrent pregnancy loss. Overall, the rate of chromosome abnormalities and the rate of miscarriage both increase with maternal age, with a steep increase in women older than 35.

Pregnancy Loss – How Common is it?

Miscarriage is far more common than a lot of people think. Up to one in every four recognized pregnancies is lost in first trimester miscarriage. The chance of experiencing a miscarriage also increases as a mother ages.

Nearly all women who experience a miscarriage continue to possess a healthy pregnancy and never miscarry again. However, some women seem to be more susceptible to miscarriage than others. About five percent of fertile couples will experience several miscarriages.

Of note, the rate of miscarriage seems to be increasing. One reason for this may be awareness – more women know they’re having a miscarriage because home pregnancy tests have improved early pregnancy detection rates in the last decade, whereas in the past the miscarriage would have were just an unusual period. Another reason may be that more women are conceiving at older ages.

Types of Genetic Testing Helpful for Miscarriages

Genetic testing actually identifies many different types of testing that can be done on the DNA in a cell. For miscarriage tissue, also called products of conception (POC), the most useful type of test to perform is really a chromosome analysis. A chromosome analysis (also called chromosome testing) can examine all 23 pairs of chromosomes for the presence of extra or missing chromosome material (aneuploidy). Because so many miscarriages are due to aneuploidy, chromosome analysis on the miscarriage tissue can often identify the reason for the pregnancy loss.

The most common approach to chromosome analysis is called karyotyping. Newer methods include advanced technologies such as for example microarrays.

Karyotyping analyzes all 23 pairs of chromosome but requires cells from the miscarriage tissue to first be grown in the laboratory, a process called “cell culture”. Due to this requirement, tissue that’s passed at home is often unable to be tested with this particular method. About 20% or even more of miscarriage samples neglect to grow and thus no email address details are available. Additionally, karyotyping is unable to tell the difference between cells from the mother (maternal cells) and cells from the fetus. In case a normal female result is found, it may be the correct result for the fetus or it might be maternal cell contamination (MCC) where the result actually originates from testing the mother’s cells within the pregnancy tissue instead of the fetal cells. MCC appears to occur in about 30% or more of the samples tested by traditional karyotype. Results from karyotyping usually have a few weeks to months to come back from the laboratory.

stillbirth Microarray testing is really a new type of genetic testing done on miscarriage samples; both most common types of microarray testing are array CGH (comparative genomic hybridization) and chromosome SNP (single-nucleotide polymorphism) microarray. Microarray testing can be able to test all 23 pairs of chromosomes for aneuploidy, but will not require cell culture. Therefore, you are more prone to receive results and the outcomes are typically returned faster when microarray testing can be used. Additionally, some laboratories are collecting a sample of the mother’s blood concurrently the miscarriage tissue is delivered to enable immediate detection of maternal cell contamination (MCC).

Chromosome Testing – How do it help?

If a chromosome abnormality is identified, the type of abnormality found can be assessed to help answer the question: “Will this eventually me again?”. Quite often, chromosome abnormalities within an embryo or fetus are not inherited and have a minimal chance to occur in future pregnancies. Sometimes, a specific chromosome finding in a miscarriage alerts your doctor to do further studies to investigate the possibility of an underlying genetic or chromosome problem in your family that predisposes you to have miscarriages.

Furthermore, if a chromosome abnormality is identified it can prevent the need for other, sometimes quite costly, studies your doctor might consider to investigate the reason for the miscarriage.

Lastly, knowing the reason behind a pregnancy loss can help a couple start the emotional healing up process, moving at night question of “Why did this happen to me?”.

Chromosome testing can be especially important for patients with repeated miscarriages, as it could either give clues to an underlying chromosomal cause for the miscarriages or eliminate chromosome errors as the reason behind the miscarriages and invite their doctor to pursue other styles of testing. For couples with multiple miscarriages determined to have a chromosomal cause, in vitro fertilization (IVF) with preimplantation genetic diagnosis (PGD) testing might be able to help increase their chances of having a successful healthy pregnancy.