Although most couples are blissfully unaware of the statistics surrounding miscarriage, pregnancy loss is actually quite common, with 10-25% of recognized pregnancies ending in miscarriage. In case you have suffered a pregnancy loss or are in the process of experiencing a miscarriage, you may well be wondering what caused losing and worry about whether it will happen again. This article aims to answer the following questions:
What causes miscarriage?
How common is pregnancy loss?
Which kind of genetic testing is available for miscarriage tissue?
How do chromosome testing help?
Causes of Miscarriage
There are many different reasons why miscarriage occurs, but the most common cause for first trimester miscarriage is really a chromosome abnormality. Chromosome abnormalities – extra or missing whole chromosomes, also known as “aneuploidy” – occur due to 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 baby to develop normally it is essential that it have exactly the right amount of chromosome material; missing or extra material during conception or within an embryo or fetus could cause a woman to either not become pregnant, miscarry, or have a baby with a chromosome syndrome such as for example 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 have 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 could it be?
Miscarriage is far more common than most people think. Up to one atlanta divorce attorneys four recognized pregnancies is lost in first trimester miscarriage. The opportunity of having a miscarriage also increases as a mother ages.
Nearly all women who experience a miscarriage continue to have a healthy pregnancy and never miscarry again. However, some women seem to be more prone to miscarriage than others. About five percent of fertile couples will experience several miscarriages.
Of note, the rate of miscarriage appears 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 over the past decade, whereas during the past the miscarriage would have were just a unique 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), probably the most useful type of test to perform is a chromosome analysis. A chromosome analysis (also known as chromosome testing) can examine all 23 pairs of chromosomes for the current presence of extra or missing chromosome material (aneuploidy). Because so many miscarriages are due to aneuploidy, chromosome analysis on the miscarriage tissue could identify the reason for the pregnancy loss.
The most common approach to chromosome analysis is named karyotyping. Newer methods include advanced technologies such as microarrays.
Karyotyping analyzes all 23 pairs of chromosome but requires cells from the miscarriage tissue to first be grown in the laboratory, an activity called “cell culture”. infant loss For that reason requirement, tissue that’s passed at home is often unable to be tested with this method. About 20% or 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 mom (maternal cells) and cells from the fetus. If a normal female result is available, it may be the right 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 even more of the samples tested by traditional karyotype. Results from karyotyping usually have a few weeks to months to come back from the laboratory.
Microarray testing is really a new type of genetic testing done on miscarriage samples; both most common forms of microarray testing are array CGH (comparative genomic hybridization) and chromosome SNP (single-nucleotide polymorphism) microarray. Microarray testing can be in a position to test all 23 pairs of chromosomes for aneuploidy, but does not require cell culture. Therefore, you are more prone to receive results and the results are typically returned faster when microarray testing is used. Additionally, some laboratories are collecting an example of the mother’s blood simultaneously the miscarriage tissue is delivered to enable immediate detection of maternal cell contamination (MCC).
Chromosome Testing – How can it help?
In case a chromosome abnormality is identified, the kind of abnormality found can be assessed to help answer fully the question: “Will this happen to me again?”. Most of the time, chromosome abnormalities in an embryo or fetus are not inherited and have a minimal possiblity to occur in future pregnancies. Sometimes, a specific chromosome finding in a miscarriage alerts your doctor to do further studies to investigate the chance of an underlying genetic or chromosome problem in your family that predisposes one to have miscarriages.
Furthermore, if a chromosome abnormality is identified it could prevent the need for other, sometimes quite costly, studies your physician might consider to investigate the cause of the miscarriage.
Lastly, knowing the reason behind a pregnancy loss might help a couple of start the emotional healing process, moving at night question of “Why did this eventually me?”.
Chromosome testing can be especially very important to patients with repeated miscarriages, as it could either give clues to an underlying chromosomal cause for the miscarriages or rule out chromosome errors as the reason for the miscarriages and allow 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 likelihood of having a successful healthy pregnancy.