Miscarriage: Causes, Symptoms, Treatment

A miscarriage, also known as spontaneous abortion, is the unexpected pregnancy loss before the period of viability and cause of haemorrhage in early pregnancy.

About 10-20% of all pregnancies end in miscarriage and another 10% are induced illegally. About 75% of miscarriage occurs in the first trimester within 12 weeks of pregnancy and are called early miscarriages.

Miscarriages that occur after 13 weeks of pregnancy are termed late miscarriages (1-2%). About 87% of women who have miscarriages have subsequent normal pregnancies and births.


The causes of miscarriage may include the following-

Genetic factors

A majority (50%) of early miscarriages are caused due to chromosomal abnormality in the conceptus. Chromosomal defects may be present in the parent’s sperm and ovum.

Some of the chromosomal abnormalities include autosomal trisomy (commonest 50%), polyploidy and monosomy (45 X).

Endocrine and metabolic factors

Luteal phase defect and poor release of progesterone result in early miscarriages as implantation and placentation are not supported adequately.

Hypothyroidism or hyperthyroidism and diabetes mellitus when poorly controlled are associated with increased miscarriage.

Anatomical abnormalities

  • Cervical incompetence
  • Congenital malformation of the uterus
  • Uterine fibroids
  • Intrauterine adhesions interfere with implantation and fetal growth


Transplacental fetal infections such as viral, parasitic, bacteria may occur and lead to fetal losses.

Other factors

  • Maternal age
  • Direct trauma on the abdominal wall by a direct blow
  • Exposure to radiation or toxic agents in excess amount
  • Blood group incompatibility includes ABO and Rh incompatibility
  • Premature rupture of the membranes also leads to abortion
  • Severe anaemia
  • Lifestyle factors such as substance use (smoking, drinking alcohol, or using illegal drugs)
  • Malnutrition
  • Interference with the circulation in the umbilical cord by knots, twists may cause the death of the foetus
  • Faulty placental formation
  • Blighted ovum (ovum without an embryo)
  • Maternal illnesses such as respiratory diseases, kidney diseases, heart failure, hypertension
  • Immunological factors may include autoimmune diseases like lupus.
Spontaneous abortion
Spontaneous abortion


Symptoms of spontaneous miscarriage may include-

  • Vaginal bleeding
  • Bleeding may range from light to heavy
  • Mild backache
  • Cramps and pain in the lower abdomen

If you experience any of these symptoms, consult your healthcare provider immediately.


Your healthcare provider may perform a pelvic examination by using a speculum and ultrasound to confirm the miscarriage. Other tests may include a blood test for ABO and Rh grouping, complete blood count and urine for an immunological test of pregnancy.


After the confirmation of the diagnosis, if you have only threatened bleeding but have not passed any mass per vagina then a doctor may advise bed rest for some days until bleeding stops. Along with bed rest, your doctor may prescribe progesterone hormone for the continuation of pregnancy. Thereafter, you can resume your daily routine activities but be cautious against strenuous work.

If the miscarriage is complete and the uterus is clear, then no further treatment is usually required. But sometimes, if the uterus is not completely emptied then excessive bleeding should be controlled by administering methergine and IV fluids are started. Dilatation and evacuation (D&E) followed by curettage is performed to remove any remaining tissue from the uterus. Your menstrual period will usually resume in about 4 to 6 weeks.

About 87% of women who have miscarriages have subsequent normal pregnancies and births. There are chances of occurrence of recurrent miscarriage in about 1% of cases. Usually, miscarriage only occurs when there is a problem in the conceptus.

When you are planning to have another pregnancy after a miscarriage then you need to talk to your healthcare provider. Usually, you can plan for another pregnancy when you feel mentally and physically ready. Your doctor may provide treatment for your medical illness to improve pregnancy outcomes. Your doctor may also prescribe progesterone hormone required for implantation and placentation for a successful pregnancy.


In the above post, we have discussed miscarriage, its causes, symptoms, diagnosis and treatment. Miscarriage is the unexpected pregnancy loss before the period of viability. It is caused by various factors such as chromosomal abnormalities, infections, immunological disorders, environmental factors, etc. To prevent further pregnancy losses, the cause has to be determined and treatment is initiated.

Thank you all!!! Hope you find this useful.

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