A miscarriage is defined as termination of pregnancy before the age of ‘viability’ or gestational weight less than 500 grams.
The age of viability varies from one country to another, depending on the advancement of medical care for extremely small babies. In Nigeria, the age of viability is 28 weeks, but in the USA, it is 24 weeks. This means that if a foetus is expelled live from the womb after this age, the doctors will make some attempt at resuscitation.
The term ‘miscarriage’ is often used interchangeably with ‘spontaneous abortion’ to differentiate it from ‘induced abortion’. It is generally accepted that miscarriage is a better expression. For the purpose of this discussion, we shall be using miscarriage to refer to any pregnancy loss that is not induced medically or surgically.
Miscarriages are quite common. It is estimated that 1 in 8 women who get pregnant will end up having a miscarriage. The good news is that, majority of women who have miscarriages can go on to have successful pregnancies. Recurrent miscarriage – having 3 miscarriages in a row – happens in only 1 in 100 pregnancies. If a woman has had recurrent miscarriages, she should be managed by a consultant-led medical team before and during her subsequent pregnancy.
Let’s talk briefly about the signs and symptoms of a miscarriage.
1. Vaginal bleeding: Slight bleeding is a common symptom of early pregnancy. This is mostly inconsequential and self-limiting. Bleeding with opening of the cervix and abdominal cramps is usually associated with heavier bleeding.
2. Leaking of water: This is seen when miscarriage occurs after the bag of water around the baby has been formed. Again, not all leakages end in complete miscarriage but they are red flags that require urgent medical attention.
3. Abdominal cramps: Cramping in the lower part of the tummy is a common sign of impending miscarriage. It feels like menstrual pain but usually more painful.
4. Dizziness or fainting: These can be due to the effect of bleeding or stimulation of the nerves around the cervix as the feotus passes through the cervix.
5. No longer feeling the symptoms of pregnancy: In some cases, the foetus may have died in the womb without coming out. This is known as a missed miscarriage. In this case, the woman may notice that she has suddenly stopped ‘feeling pregnant’. Nausea, bloating and breast tenderness are some of the symptoms that may disappear in missed miscarriage.
WHAT ARE THE CAUSES OF MISCARRIAGE?
The commonest cause of miscarriage is no cause at all! There are some factors that may determine the likelihood of a pregnancy ending in a miscarriage, however, most of them are due to chance only. For better understanding, let’s classify miscarriages into FIRST TRIMESTER and SECOND TRIMESTER miscarriages.
First trimester miscarriages are usually caused by a problem with the foetus while second trimester miscarriages are often due to problems with the mother. A third source of problem could be the placenta but this can happen at any trimester.
First trimester pregnancy losses are caused by chromosome problems in about 75% of cases. Chromosomes are a stack of DNA which contains “codes” that determine the development of the foetus. Any abnormality in the number or structure of these chromosomes can lead to failure of the pregnancy to develop. Note that chromosomal anomalies have little or nothing to do with the woman or her partner. These are random events that can happen to anyone. However, there are some risk factors that may increase the risk:
1. Maternal age above 35
2. Paternal age above 40 (controversial)
3. Maternal chronic health conditions such as Diabetes
4. Maternal obesity
5. Maternal alcohol abuse, smoking or recreational drug use.
6. Maternal exposure to ionizing radiation
7. Maternal use of anticonvulsant medications
8. Maternal infections such as syphilis, rubella, etc.
At this point, it is safe to say that first trimester miscarriages are not always preventable because they are mostly due to chance. But the risk factors can be modified to reduce the risk of recurrence.
Folic acid is a vitamin that helps to ensure proper development in the first few days of pregnancy — even before the pregnancy test turns positive! This is why we encourage women to start taking it 3 months before they try to conceive, until 3 months of pregnancy (first trimester). The recommended dose is 0.4mg daily but women who have one or more of the risk factors mentioned above should take up to 5mg or as advised by the doctor.
As mentioned earlier, second trimester (14 to 26 weeks of gestation) miscarriages are often due to health problems with the mother herself. These account for less than 25% of cases. Some conditions may have been diagnosed before pregnancy, availing the opportunity to put in preventive measures. Examples of the risk factors for second trimester miscarriages include:
1. Poorly-controlled diabetes
2. Severe hypertension
3. Chronic kidney disease
4. Thyroid dysfunction
5. Antiphospholipid syndrome
6. Infections, such as Urinary tract infections, genital infections, chest infections, malaria, diarrhoea, sepsis, etc.
7. Food poisoning, causes by toxoplasmosis, salmonella, etc.
8. Toxic drugs, such as ibuprofen
9. Cervical incompetence – weakened cervix
10. Structural anomalies of the womb – such as ‘septate uterus’
*This list is not exhaustive.
The best way to tackle these conditions is to identify them promptly and start the treatment before any damage is done to the developing baby. Time will not permit us to explain all of them in details, but I will touch on two important ones namely; ANTIPHOSPHOLIPID SYNDROME and CERVICAL INCOMPETENCE.
Antiphospholipid syndrome occurs when the body produces certain antibodies which affect the body’s ability to control blood clotting. Blood clots can be formed anywhere in the body including the placenta in a pregnant woman. When blood clots are formed in the placenta, blood flow to the baby will be obstructed, and this results in death.
This condition is detected by a specialized blood test which should be done if the woman has had 3 consecutive miscarriages with no other identifiable cause. Once confirmed, further occurrence can be prevented by taking daily tablets of aspirin and heparin injections to block the formation of clots.
Cervical incompetence is another important cause of second trimester recurrent miscarriages. This happens when the cervix (‘mouth’ of the womb) is too weak to sustain the weight of the growing pregnancy. This can be a result of anatomical problems with the cervix or accidental damage during previous childbirth.
Cervical incompetence is diagnosed with the aid of an ultrasound scan showing the size (length and diameter) of the cervix. Normally the cervix should be more than 3cm long and closed until the onset of labour. Women with history of painless, second trimester pregnancy loss should be tested by the 12th week of the next pregnancy. If the cervix is found to be ‘weak’, there are two main methods of keeping it closed until term:
1. Medical method: Research has shown that the use of progesterone (by mouth or by insertion into the vagina) can help prevent miscarriage in high risk women. This method has shown similar efficacy with the surgical method according to some studies.
2. Surgical method: The use of stitches to close the cervix has helped to prevent thousands of miscarriages. The procedure is known as cervical CERCLAGE (pronounced ‘serk-leij’). There are pros and cons to this procedure with particular concerns for bleeding and infection. But by and large, it is has proven to be an highly effective remedy. The stitches should be inserted around 14 weeks and removed by 37 weeks to avoid further trauma during labour.
MEDICAL CARE DURING AND AFTER A MISCARRIAGE
Losing a pregnancy can be physically and mentally challenging for couples. It is important to identify the early warning signs (such as tummy cramps and vaginal bleeding). It is possible to reverse the course of an impending miscarriage but this is rarely achieved due to late arrival at the health center. Failure to seek immediate medical attention and ongoing psychological support, may result in further complications (such as blood transfusion, infection, infertility, depression, etc.)
The management of miscarriages depends on the type of presentation. Below is a quick overview:
1. Threatened miscarriage: comess with mild cramping and slight bleeding but the cervix remains closed. Can be abated by rest, avoiding sexual intercourse and use of progesterone (controversial)
2. Incomplete miscarriage: here, the cervix is open, some bleeding is evident and part of the *products of conception may have been expelled.
3. Inevitable miscarriage: the cervix is open, bleeding and leaking of water may have occurred, and the *products of conception can be seen coming out irreversibly.
4. Complete miscarriage: the cervix is closed after expulsion of the products of conception. Some bleeding (like menses) may continue for about 2 weeks or less.
*Products of conception: this consists of the foetus, placenta and other tissues formed within the womb after conception. The term is used to describe all the materials expelled during a miscarriage, including blood and flesh*
Irrespective of the presentation, the woman must be examined and placed under close monitoring, either at home or at the hospital. The following tests must be carried out:
-Full blood count
-Pelvic ultrasound scan
-Kidney and liver function test (optional)
-Blood grouping and antibody testing (to determine the need for Rhogam)
-Group & save or Crossmatching (in case she needs transfusion)
-Septic workup (if she comes with signs of infection)
-Other specific tests (depending on the circumstances)
Treatment options are broadly classified into 3:
I. Expectant/conservative management: The miscarriage can be allowed to take its course without any intervention. This will allow the woman to stay at home with the support of her loved ones. To be eligible for this option, the initial tests mentioned above must be normal and she must have direct access to return to the hospital in case of emergency. With expectant management, it can take up to 2 weeks or more for bleeding to stop. Pain control and rest must be taken seriously, to reduce the level of distress.
II. Medical management: The woman will be admitted for about 2 days and given some medications by mouth, through the vagina or by intravenous drip. The most common medicines used are misoprostol and oxytocin. Similar to the process of inducing labour, these medicines cause the uterus to contract and the cervix to dilate, so that the uterus can be evacuated.
III. Surgical management: This can be done on request by the woman or in emergency cases where bleeding is too heavy and we cannot use the first two methods. There are many techniques that can be used depending on individual case. But the commonest is known as dilatation and curretage. It is usually carried out in the operating theatre but it takes just a few minutes and the woman can be discharged home the same day. Another advantage is that bleeding is uncommon after the procedure. Complications (like perforated uterus and infection) are rare if done by a skilled personnel in an ideal setting.
Last but not least, women and their families should have access to post-miscarriage counselling sessions. This will help them to recover quickly and move on with their lives. It is important to let them grieve, have a look at the miscarried baby if they wish and assist them with funeral rites if applicable. It is also important to seek their consent before taking tissue samples from the baby for laboratory testing (such as chromosomal analysis).
Sexual intimacy can be resumed as soon as the miscarriage is complete and bleeding has stopped. Pregnancy is possible as early as two weeks after a miscarriage provided the woman feels ready. However, there are some women who may need to undergo further tests before they try for another baby to avoid a recurrence.
Some ideas used in writing this piece were sourced from the NHS website.