Miscarriage causes, signs and reasons

Several risk factors have been associated with a miscarried foetus. These include older age, obesity, and lifestyle habits like alcohol and smoking. However, the woman is generally not responsible for it.

Let us look at some of the evidence-based factors that are responsible for miscarriage in the first and second trimester.

Chromosomal abnormalities

A baby receives half of its DNA from each parent, therefore, any abnormality in parental chromosomal structure can be transferred to the foetus. An abnormal karyotype (chromosomal structure) in the foetus is one of the most common reasons for early and repeated miscarriages. However, studies suggest that couples who carry such abnormalities are equally viable of normal pregnancy as non-career couples even though they have a higher chance of miscarriage.

(Read more: Karyotype test)

Also, there are chromosomal tests that can determine if the parents carry such an abnormality in their DNA. You can get medical counselling about the best way to conceive in such conditions. Even though these are a bit costly, a DNA analysis is usually advised in case of recurrent miscarriages. So, this is definitely not something to worry about.

Usually, preimplantation genetic diagnosis (PGD) is believed to increase the chances of a live birth but the evidence is insufficient. In vitro fertilisation may also be a way to conceive in such cases.

Thyroid dysfunction

An increased level of Human chorionic gonadotropin (HCG) has effects on various thyroid hormones. While the condition is reversible and non-harmful in most women, it might pose a threat of miscarriage and stillbirths in women who already have hormonal abnormalities. According to a study, normal but elevated levels of TSH levels, >2.5 mlU/L increase the risk of miscarriage.

(Read more: Thyroid problems during pregnancy)

The same goes for women with thyroid autoimmunity (when the body makes antibodies against the thyroid gland). One belief is that a higher number of autoantibodies delays conception and stimulates the immune system, in general, leading to spontaneous loss of the foetus. However, it was found to be independent of thyroid autoantibody titer.

(Read more: How to get pregnant with thyroid problems)

PCOS or polycystic ovary syndrome

PCOS is yet another hormonal imbalance that has been found to be responsible for early pregnancy loss. Extensive research has been done to understand the underlying mechanism behind this condition. However, the evidence is inconclusive. A number of factors are associated with PCOS related miscarriage. These include:

• Obesity
• Abnormal luteinizing hormone
• Increased insulin resistance
• Endometrial dysfunction
• Increased blood clotting in placenta

Immune dysfunction

While the maternal immune system is known to support implantation, there is controversial evidence that dysfunction in the mother’s immune system may terminate a pregnancy. On a general note, autoantibodies have been associated with an increased risk of recurrent miscarriage. Animal studies link the absence of certain immunological molecules to foetal loss.

According to a study published in Human reproduction, miscarrying women have an increased TNF level and Inflammation. In a previous study, imbalances in NK (natural killer) cells activation and function are claimed to be responsible for early termination of pregnancy.

Thrombophilia

Thrombophilia refers to a condition wherein the body is predisposed to increased blood clotting. It can either be genetic or acquired. Studies suggest that women who suffer from thrombophilia are at a higher risk of miscarriage due to clot formation and restriction of blood flow to the placenta. Clinical studies demonstrate that using low doses of anti-clotting medicines may increase the chances of foetal survival in these women. However, the evidence is not that strong. So, if you are suffering from thrombophilia, it is strongly recommended that you talk to your doctor instead of self-medicating.

Ectopic pregnancy 

Ectopic pregnancy happens when the embryo implants itself inside the fallopian tube. Since the fallopian tube cannot extend beyond a particular size, this type of pregnancy either terminates or needs to be removed as it can pose a serious threat to the mother. Statistics suggest that one in four ectopic pregnancies turn into a miscarriage.

Some of the common symptoms of ectopic pregnancy include:

• Vaginal bleeding characterized by dark coloured discharge
• Abdominal pain
• Pregnancy test turning negative after a few days.
• Intense pain that reaches the shoulders
• Dizziness
• Nausea
• Diarrhoea

If you notice any of these signs, it is advisable that you immediately consult your doctor.

Sperm DNA fragmentation

A number of studies have been done to assess the effects of fragmented sperm DNA on the ease of conceiving. The results aren’t without contradiction. However, a study published in the ARC Journal of Gynaecology and obstetrics suggests that a higher level of sperm DNA damage is associated with an increased risk of miscarriage especially in case of recurrent pregnancy loss.

(Read more: Sperm DNA fragmentation test)

Other reasons for miscarriage

Apart from the above factors, miscarriage may also be caused due to:

• Being underweight
• Sexually transmitted diseases
• Fibroids
• Infections like listeriosis and salmonellosis
• Chronic diseases including high blood pressure, diabetes and lupus
• Abnormal uterus shape
• Certain type of drugs like NSAIDs
• Weakness in cervix walls, which may or may not be caused due to a surgical procedure
• Low levels of HCG (human chorionic gonadotropin)

What does not cause miscarriage in healthy women 

• Exercising
• Sex
• Earlier miscarriage
• Heredity
• Sudden Shock
• Morning sickness
• Using contraceptives before pregnancy

Depending on the development status of the embryo and amniotic sac integrity, miscarriage can be of the following types:

Threatened miscarriage: As the name suggests, it is not an actual miscarriage but may lead to a miscarriage if left uncared for. It is usually characterized by vaginal bleeding and cramps but the internal os is still closed. Fortunately, less than 5% of threatened miscarriage advance to complete miscarriage.

Inevitable miscarriage: This type of miscarriage is caused due to breaking down of the amniotic sac before 20 weeks of pregnancy. The symptoms include vaginal bleeding and cramps, although the foetal content is not expelled yet. There is no chance of foetal survival in this type of miscarriage.

Incomplete miscarriage: Apart from vaginal bleeding and back pain, foetal residues are also washed out from the uterus. Though, some parts of the amniotic sac may still remain inside the uterus. There is also an increased risk of infection.

Complete miscarriage: All the contents of the uterus, including foetus and the amniotic sac, have been washed out and the cervical os is closed. The endometrium is less than 15 mm thick.

Delayed miscarriage: Also known as a missed miscarriage because the foetus may remain in the uterus for up to four weeks before it can be detected. But the mother may experience a reduction or total absence of pregnancy symptoms like mood swings and morning sickness.

Blighted ovum: Placenta and amniotic sac are developed but the embryo is not fully developed so the gestational sac is empty. Miscarriage usually follows a  blighted ovum.

Recurrent miscarriage: This is when a woman miscarriages more than 2-3 times consecutively.

The signs and symptoms of miscarriage may vary depending on its type. However, it is almost always linked to sharp pains in the abdomen and vaginal bleeding, which might either be light or heavy. Some women just experience spotting, though, spotting in early pregnancy is not always an indication of a miscarriage.

(Read more: Implantation bleeding symptoms)

If you have any concerns, it is best to talk to a gynae. Let us look at some of the symptoms and signs that associate miscarriage.

• Abdominal cramps
• Spotting or vaginal bleeding that may last for days.
• Absence of the usual symptoms of pregnancy
• Clots or a dark vaginal discharge
• Tissues in the vaginal discharge.
• Frequent and regular contractions

In spite of all of these symptoms, the doctor would need to do an ultrasound to confirm pregnancy loss in the early stages. However, the symptoms are much more apparent in the later trimesters.

According to the American Pregnancy Association, young fertile women have a 10 to 25 % chances of having a miscarriage and this percentage increases with age. However, a previous miscarriage does not ascertain that the women will lose her pregnancy again. Here is a table that sheds some light on probable miscarriage chances by age.

Unfortunately, once a miscarriage happens, there is no way to save the foetus. The main aim of miscarriage treatment is to stop excess bleeding and the development of infections in the mother.

However, a threatened miscarriage can be saved as there has been no harm to the foetus so far. Adequate rest and abstaining from sex are two of the best ways to sail through this problem with ease. Though a gynae may know better about your individual situation.

The foetus and gestational sac may or may not wash out itself (usually it does in early pregnancy). A D&C (Dilation and curette) may be referred, wherein, the cervix is dilated to remove the remaining foetus from the mother’s body. After a D&C, a woman may bleed up to 10 days. But if you develop fever, heavy bleeding or excess pain, check in with a physician without any delay.

For a healthy pregnancy, it is best to follow a balanced diet and a stress-free lifestyle. There are several other things that you can do prevent miscarriage.

• Avoid alcohol
• Stop smoking
• Exercise regularly
• Practice mindfulness or maternity yoga
• Follow your doctor’s advice and never miss an appointment
• Take a nutritious diet
• Keep tabs on abnormalities and immediately seek medical advice if you feel any distress

A miscarriage might take some or a lot of time to heal from, depending on the emotional and physical state of the woman. Since vaginal bleeding and pain carries on for some time proceeding pregnancy loss, there are certain things to be kept in mind to make the healing quicker and return to your pre-pregnancy state easily. Let’s have a look at them.

• Do not miss on antibiotics prescribed by the doctor
• Use sanitary pads instead of tampons
• Refrain from sex until you don’t stop bleeding
• An Rh-negative woman may require an anti-D-immunoglobulin injection after a miscarriage to avoid an immune reaction in the following pregnancies
• Talk to your doctor if you notice excessive bleeding, increased clotting or bad odour in the vaginal discharge.
• Women who lose their pregnancy around the 20th week may notice some milk secretion from their breasts. It is advisable to consult a physician to know the right action in this condition.
• Painkillers can be taken to subside the pain
• The doctor may or may not need to monitor your haemoglobin levels. (Read more: Haemoglobin test)

By now you may already be aware that pregnancy loss is not a woman’s fault and one miscarriage doesn’t mean that you can’t conceive again. In fact, a woman returns to her fertile state as soon as the miscarriage symptoms subside after the first period generally falling within a month of miscarriage. But the emotional shock might take much longer to wane. Professional counselling may or may not be needed but the best way to cope with this is through family support.

It is strongly recommended that you talk to a healthcare professional to know the exact reason for this miscarriage. So, it can be corrected or managed in the future. This is especially important if you have a previous history of miscarriage.

You might also need to look into contraceptive methods to take some time before conceiving again.