What to do with repeated miscarriages

Correspondent | Friday June 23, 2017 14:53

 

Expectedly, loss of pregnancy is a harrowing experience to any couple who would have prepared themselves psychologically, financially, socially and otherwise to receive a new member of the family.

Worst still, more often, the couple may have informed closer members of the family, friends and work mates of the impending arrival of the baby. Not only does a couple have to deal with the loss, but the additional burden of having to tell a larger circle of family and friends brings a lot of stress and strain in the relationship.

Having two or more pregnancy loses consecutively brings a lot of uncertainty pertaining to the reproductive potential of the couple, transference of blame to one member of the couple and within the context of the Setswana family setup, a lot of uncertainty about the survival of the relationship owing to social pressures.

Predictably a couple finding themselves in this vulnerable situation would like to know why it happens, whether something can be done and if it will happen again.

In the third world where women are less likely to remember their menstrual cycles, the World Health Organisation suggests that we define a miscarriage for any baby born with a weight less than 500g. Depending on whether the doctor leans towards the American definition or the UK definition, they may start investigation you for recurrent miscarriage at your second or third miscarriage, respectively.

Using the UK definition, recurrent miscarriage is a common condition which happens in one out of 100 couples.

There are many reasons for the occurrence of recurrent miscarriage. These range from chromosomal abnormalities, clotting abnormalities (thrombophillia), presence of congenital abnormalities of the uterus, uterine fibroids, uterine polyps, presence of bands and adhesions within the uterus, cervical incompetence, persisting infections within the uterus and hormonal imbalance issues.

The multiplicity of the causes of the causes of recurrent miscarriage means a lot of investigations be conducted to rule out each cause and a specific solution be offered to treat the underlying medical cause.

The most common cause of repeated early pregnancy failure is the presence of chromosomal abnormalities in the baby so formed. The reason for chromosomal abnormalities is largely due to the fact that in a normal female only 50% of her eggs are chromosomally normal. Consequently 50% of the eggs ovulated would not result in a live birth.

It is in the order of nature that chromosomally abnormal babies are naturally miscarried by the body. Over 60% of these miscarriages happen even before a positive pregnancy, right at the time when the chromosomally abnormal baby tries to implant into the womb.

As the female ages, the number of chromosomally abnormal eggs increases, ever-increasing therefore the likelihood of miscarriages. To this end it is important for one to not that below the age of 25, 10-15% of women will miscarry naturally. By age 35-39 about 25% (one out of four) couples would experience a miscarriage.

 At the ages of 40-44 about 50% of women will miscarry, while women at 45 years and above would experience miscarriage in 75% of pregnancies they conceive. Consequently, the most common cause of miscarriage has nothing to do with anyone, it is purely a chance event of one ovulating a chromosomally normal egg, and being a chance event it has good prospects for conceiving a normal baby.

One important cause of recurrent miscarriage is mistaken rearrangement of chromosomes during the formation of eggs and sperm. In this instance, the parents appear normal and indeed have normal number of chromosomes, although one of them is carrying a mistakenly rearranged chromosome.

Although the chromosomal number may appear to be alright, segments of one or more chromosomes may have been donated to other chromosomes that formed a different sperm or egg. In the so formed sperm or eggs there could either be a missing segment or one extra segment of a chromosome. This scenario is what is called an unbalanced chromosomal abnormality in the so formed egg or sperm.

In the parent that produced the unbalanced egg or sperm they would be having a balanced chromosomal abnormality, that is only unbalanced in the egg or sperm they form. Either way these chromosomally unbalanced eggs or sperm are rejected by the female womb after fertilisation when the product of their creation, a chromosomally abnormal baby fails to implant in the womb.

We find this situation of balanced parental chromosomal rearrangement in three to five percent of couples with recurrent miscarriage, compared to 0.7% in the general population. A simple test would be able to tell if one of the couple has a balanced chromosomal abnormality. It is however recommended that when you do have a second or more miscarriages you safe the products of the pregnancy and give them to your doctor in order to send them for chromosomal studies.

Even in the phase of a balanced chromosomal abnormality, a normal pregnancy is possible, further counselling with your doctor would provide you available options to manage this scenario. The third important cause of recurring early pregnancy failure is problems associated with the womb. These could be congenital in nature meaning you were born with them or they happened as you aged.

The womb is formed from the merging of the two fallopian tubes earlier on during the knitting together of the female baby. The tubes are brought together such that they lie side by side with their wall touching.

These walls merge into each other then dissolve leaving an open space we call the uterine cavity, the space within which the baby develops. Sometimes the touching walls fail to come together closely enough to fuse into each other. These leaves a woman with two wombs, not big enough to function properly.

Sometimes they fuse but fail to dissolve. Sometimes they dissolve to varying degrees leaving varying degrees of the remnants of the touching wall. We call this scenario a septum. If you do have a septum then you will miscarry 60% of your pregnancies. A good transvaginal scan by a competent sonographer or physician may raise suspicion of a congenital anomaly. Following this a confirmatory test with a hysteroscopy(a camera into your womb) with or without key whole surgery is required to confirm the nature of the abnormality.

 The septum would need to be removed in order for pregnancy to be carried to term. Other kinds of abnormalities would require specific treatment or even further investigations with more expensive tests depending on the nature of your presentation.

The presence of uterine fibroids is another important cause of miscarriage. Studies have shown that if you have fibroids inside the womb this would lead to repeated pregnancy loss. Where fibroids are within the walls of the uterine muscle and yet distort the cavity this has the same effect as if they were inside the womb.

Fibroids would reduce the chance of implantation, ongoing pregnancy and ability to have a live baby in addition to causing a miscarriage. The size, number and location  of the fibroid determines the severity of the impact on miscarriage and pregnancy rates. A good scan and a competent sonographer or physician is all that is required to diagnose fibroids.

While it appears obvious that removing fibroids would improve fertility, studies have not categorically made this clear. One reason why this is not easy to conclude is that success of the operation is tied to the competence of the surgeon and hence the damage caused to the uterus during the surgery.

It is recommended that removal of fibroids for those wanting to conceive be done through a key hole surgery due to its reduced likelihood to cause harm to the uterus predisposing the womb, ovaries, tubes and bowel to get stuck together after the operation. The other problem that often may happen is the sticking together of the womb walls after surgery.

This happens if the operation was deep enough to breach the uterine cavity.

Other causes of recurrent miscarriage within the uterine cavity include the presence of uterine bands (adhesions) and uterine polyps. Uterine adhesions may result from any procedure done in the uterus such as cleaning the womb after a miscarriage, after removing a very adherent placenta, following fibroid surgery or any surgery inside the womb.

Adhesions cause the walls to get stuck together, leaving no space for the incoming embryo to implant. Usually there would very limited lining of the womb to support implantation. Previous exposure to infections such as tuberculosis, syphilis, bilharzias and sexually transmissible infections may cause inflammation that causes formation of bands of adhesions inside the womb. Adhesions may not be obvious on the scan.

In some cases they suggested in a test which tests the patency of your tubes.

Otherwise adhesions are mainly diagnosed by a hysteroscope. Following diagnosis these may be removed and improve your likelihood of carrying a pregnancy to term.

Uterine polyps are mostly finger-like out-growths of the lining of the womb which excessively responded to stimulation by the female hormone oestrogen. Bigger polyps may be suggested by a ultrasound scan. However a diagnosis of these can be made by a hysteroscope. It is more common that other tests may return a normal result while you in fact have uterine polyps.

 The presence of these has been shown to reduce the chance of pregnancy by up to 35%. More reassuring is the fact that removal of uterine polyps is associated with improvement in pregnancy outcomes.

Cervical incompetence is one other cause of repeated pregnancy failure. Cervical incompetence refers to failure of the cervix to competently hold on to a pregnancy as the weight of the conception increases with increasing gestation. In this case any instrumentation of the cervix for any procedure done inside the cervix may be the cause.

One other important consideration in the African context is procurement of back street abortions. Yet it is also known that cervical incompetence may happen naturally in very rare circumstances in women with connective tissue disorders. Cervical incompetence would present with the breaking of the waters before the onset of pains, or a description of the bulging of membranes through the vagina un-associated with pain.

Investigations for incompetence of the cervix may include serial vaginal swabs by your gynaecologist and serial ultrasound scans. A stitch is then inserted around the cervix when your pregnancy is around 13 weeks to give strength to the cervix which would be removed when your pregnancy reaches 37 weeks.

Abnormal clotting of your blood may be responsible for causing recurrent pregnancy failure. This happens due to genetic mutations of components of your clotting system. When these happen you have increased likelihood to form clots.

More likely, this would cause your blood bathing the small baby’s placenta to clot leading to the death of the baby very early. The association of repeated miscarriages a history of clot formation in your calves or lung puts you particularly at risk of a particular form of clotting abnormally called antiphospholipid syndrome.

A number of test would need to be done to rule out a host of conditions all of which increase the likelihood of forming clots, collectively known as thrombophillia. Once a diagnosis has been treatment can be given in the form of an anticoagulant or aspirin.

Hormonal imbalance is another recognised cause of repeated miscarriages. This happens if you conditions such an under active thyroid with or without presence of auto-antibodies, over active thyroid, high prolactin, established diabetes and luteal phase defect.

In the case of hormonal imbalance a blood tests for hormones would be checked and if anomally be detected you may be referred for treatment by specialists or may be commenced on appropriate treatment. One important point to be made is hormone balancing is only possible in the case of thyroid, prolactin, diabetes etc. It is not possible to medically balance female hormones by giving you a pill.

The oral contraceptive pill often given for hormonal imbalance does not correct hormonal imbalance, rather it merely causes oestrogen withdrawal affording you the opportunity to have a period. Other causes of recurrent miscarriage fall in the realm of repeated implantation failure that is beyond the confines of this paper.  These include abnormal sperm DNA (DNA fragmentation and packaging), poor sperm and egg quality, failure of the egg to hatch from its shell just before implantations and the hostile uterine lining.  

Otherwise, it can be seen that while it may appear hopeless, a careful investigation into the cause of recurrent miscarriage may find a cause and with that a possible treatment. Even if the cause is never found pregnancies happen in the order of 50-60% over a three to five follow up. 

*Dr Vincent Molelekwa is a obstetrician, gynaecologist, fertility specialist (MB BCh BAO BmedSc DRCOG MRCOG MRCPI FRM)