You and your husband have wanted to start a family ever since you met, but the journey to conceiving a baby hasn’t been as smooth sailing as you imagined. A couple of years ago, you endured your first miscarriage. After taking some time to recover emotionally and physically, you decided to try again. But three months in, another devastating blow occurred - a second miscarriage.

Now that you’re considering trying a third time, you’re wondering whether there’s something wrong. Why do you keep having recurring miscarriages? And is there something you can do to ensure a successful pregnancy?

Enduring recurrent miscarriages is one of the most devastating life events a person can go through. It’s common for the person who keeps having them to wonder if they will ever reach their end goal of producing a healthy baby. If you can relate to this, then we want you to know that we feel your pain, you are not alone, and that most of all, you and your body are NOT a failure.

Throughout the terrible frustration and pain of recurrent miscarriage, some parents find it helpful to have some understanding of the science behind the anatomical issues and maternal disorders that can cause this.

Here are some of them:

Congenital abnormalities of the uterus

Although it is unknown how many women have a congenital abnormality of their uterus, studies have suggested that as few as 1 in 1000 women (0.1%) are affected. Others suggest that as many as 1 in 10 women (10%) have an abnormality. The truth is that these figures depend on how many women are studied, and the actual figure probably falls somewhere in between.

The most common uterine abnormality is a bicornuate uterus, a condition where the two tubes of uterine tissue (which are called horns) haven’t fused together and the uterus ends up having the appearance of two horns joined together at the cervix. In this instance, the baby might not have enough room to grow to its proper size, which can result in a premature labour or a late miscarriage.

Other congenital abnormalities include a septum in the uterine cavity.

Diethylstilboestrol (DES-related abnormalities)

Diethylstilboestrol (DES) is a synthetic oestrogen, and, ironically, was used to treat women in the 1940s who were at risk of miscarrying. This substance actually caused problems in the daughters of the women who had been treated with it, and was therefore removed from the market. These problems included the occurrence of a rare type of vaginal and cervical ‘clear cell’ cancer. However, DES-related abnormalities are very rare these days, as only a few daughters that were exposed to the drug are still of childbearing age.

Fibroids

Uterine fibroids are very common, and a bit of a mystery to doctors, as it is not really known how they develop. They are the most common benign (non-cancerous) growth in women, and can cause both infertility and miscarriage. Their size can range from a small pea to a large melon, and it is thought that as many as 50% of women will develop fibroids in their lifetime (usually not before the age of 20, and not after the menopause).

While some women with fibroids will become pregnant without delays and won’t experience complications, some fibroids can distort the uterine cavity, cause reproductive problems and trigger premature labour. There are various treatments for fibroids, including some minimally invasive ones such as uterine artery embolization.

Intrauterine adhesions

Intrauterine adhesions are a very common problem in women. They are fine bridges of fibrous tissue that can cause the walls of the uterus to stick together. The adhesions can stop the endometrium from thickening at the appropriate time in the women’s menstrual cycle. This can sometimes prevent the embryo from implanting successfully. In mild cases, sometimes waiting and doing nothing will allow the problem to resolve itself.

However, if this problem continues, having the adhesions divided is advised.

Uterine adhesions are usually responsive to treatment and won’t cause long-term problems.

Cervical incompetence

Sometimes, the muscles of the cervix are weak, and the cervical canal can start to open during the second trimester of pregnancy. This situation is called ‘cervical incompetence’ and can be caused by a congenital abnormality of the muscles of the cervix. It can also arise from a difficult vaginal delivery where the cervix is torn by forced blades or a particularly large baby.

As cervical incompetence can cause the cervix to disperse bacteria into the vagina and therefore the pregnancy, this can cause infection both to the fetus and the placenta. This in turn can cause a miscarriage to happen.

What are the maternal disorders behind recurrent miscarriage?

Unii looks at one of the most difficult subjects there is for any mum-to-be.