Miscarriage wasn’t something you ever imagined would impact you, your life, or your family. It was a passing advert on the TV, a storyline in a soap opera, or a tragic event that happened to a friend of a friend of a friend.

But it wasn’t something you ever thought would happen to you.

Having recently suffered a miscarriage, you and your partner have been feeling completely lost. While you’ve had lots of support from your family and friends, the question that’s been plaguing you both more than anything is,

Why?

Suffering a miscarriage is one of the most painful and confusing things a couple can go through. And one of the biggest questions many couples find themselves mulling over is - Why did the miscarriage happen? The truth is that a sporadic miscarriage can occur for many reasons. While it is often described as an “episode of bad luck” or “just one of those things”, it’s important to understand the scientific reasons behind this unfortunate part of life.

So, here are some of the most common reasons why a miscarriage can occur:

Genetic abnormalities in the baby

One of the most common causes of a sporadic miscarriage is a genetic abnormality in the embryo or tiny baby. These can be divided into three main headings: chromosomal abnormalities, gene defects, and congenital malformations. Let’s take a look at each of them now.

Chromosomal abnormalities

This can occur before, during and after the process of fertilisation, when the two sets of chromosomes undergo a complicated series of divisions and rearrangements. During this time, if too many or too few chromosomes are left in the fertilised egg, then an abnormal embryo can develop. Abnormal embryos seem to find it difficult to implant successfully, and therefore it can result in a miscarriage.

Although there are many types of chromosomal abnormalities, the most common defects are monopolies, polyploids, and trisomies.

Structural rearrangements

Structural arrangements are changes in individual chromosomes, which can happen randomly in the sperm or egg. They may also be inherited from a parent that carries a genetic defect in one of their chromosomes.

Other chromosomal abnormalities

Other chromosomal abnormalities include Klinefelter’s syndrome, which is when the man has an extra X sex chromosome. This syndrome brings an extra chromosome that can produce a mild abnormality. Other types of abnormalities include mosaicism, which occurs when an individual may be carrying two different cell lines made up of different chromosome numbers.

The vast majority of chromosomally abnormal pregnancies are miscarried at an early stage.

Single gene defects

Another cause of miscarriage are single gene defects, such as Duchenne muscular dystrophy and haemophilia, where the mother has passed on a second X chromosome.

Polygenic / Multifactorial defects

Examples of polygenic or multifactorial defects that can cause miscarriage include congenital heart defects, hip dysplasia, club foot, neutral tube defect, and Spina bifida.

Drugs, infections, and environmental factors

Miscarriage is also caused by drugs, environmental factors, and infections, as all of these can result in congenital abnormalities. A recent example is the Zika virus which leads to microcephaly. Another example is thalidomide, which causes limb malformations called phocomelia. Environmental factors such as pollutants have also been associated with the cause of a miscarriage.

Abnormalities of the uterus and cervix

Abnormalities of the uterus and cervix are also known causes of miscarriages. These abnormalities may be congenital (the mother is born with a double uterus, for example), or they may be discovered later on. Some other examples of abnormalities of this kind include uterine fibroids and the development of adhesions.

Infections in the mother and in the baby

1 in 20 pregnant women will experience an infection during their pregnancy. Although many of these infections are harmless, some of them are capable of causing miscarriage. Most bacterial and parasitic infections can be successfully treated if correctly identified.

Here are some examples of the viral infections that can cause sporadic miscarriage:

Rubella

Rubella (or German measles) can have very bad effects on the foetus if the mother develops it in early pregnancy. It can cause blindness, deafness, heart defects, and mental retardation in the foetus. The best way to protect a pregnant woman against rubella is to ensure they have had two measles, mumps and rubella (MMR) vaccinations before they become pregnant.

Genital Herpes

There are two types of herpes virus infections. There is Type 1, which affects the lips and mouth, and Type 2, which affects the vulva, vagina, and cervix. If a woman develops her first genital herpes infection (Type 2) during pregnancy, this can cause a miscarriage. Similarly, if she develops a lesion around the time of delivery, it can infect the baby and be fatal. The foetus can only be infected during the course of the mother’s first herpetic infection and won’t be affected by any recurrences.

Some other causes of miscarriage include:

Chicken-pox, Parvovirus, Cytomegalovirus, Influenza, Mumps, Listeria, Brucellosis, Chlamydia, Salmonella, Parasites, Malaria, Hormonal causes and Immunological causes.

Why did I miscarry?

Unii addresses a heartbreaking question for any woman.