If I had a miscarriage, do I need to tests to determine the cause?

Your fertility doctor may recommend certain tests if you have had three or more consecutive miscarriages. (Three or more miscarriages constitute infertility.) These tests can determine underlying conditions, such as problems with your uterus or placenta or hormonal imbalances.

What is a miscarriage?

A miscarriage is a loss of pregnancy in the first 20 weeks. Majority of miscarriages in the first trimester are thought to be caused by chromosomal abnormalities in the fertilized egg. This can happen when the egg or the sperm had the wrong number of chromosomes, and as a result the fertilized egg fails to develop properly. Other reasons for miscarriages include the egg not implanting properly or issues with early embryonic development.

Symptoms of a miscarriage:

  • Vaginal spotting or bleeding
  • Abdominal pain
  • Pelvic Pressure
  • Lower back pain

It's important to consider that these symptoms during early pregnancy can also be signs of an ectopic pregnancy. Call your doctor immediately if you suspect you've had a miscarriage, he will order an ultrasound to determine the problem. 

After having one miscarriage, most women go to have a healthy pregnancy, however there are a few women that will continue to have two or three more miscarriages. Women are considered to have recurrent miscarriages when they have two or three miscarriages in a row. About 1 percent of women will have three or more consecutive miscarriages.

What are the potential causes of recurrent miscarriages?

The specific cause for a recurrent miscarriage can be identified in about 50 percent of cases after testing. 

1. Genetic Factors

 Chromosomal abnormalities are more common in women who are over 35. These may be evaluated by chromosomal analysis of both partners or genetic analysis of the miscarriage tissue

2. Anatomical Factors

Uterus abnormalities account for 10 to 15 percent of recurrent miscarriages. Some women may have a double uterus or an abnormally shaped uterus from birth. Other problems include scar tissue or fibroid growths on the uterus. 

Second trimester miscarriages may be caused by incompetent cervix. This condition may require a surgical procedure called Cerclage to keep the cervix from dilating prematurely. 

3. Hormonal Factors

Low progesterone Levels: Progesterone is responsible for preparing the lining of the uterus for implantation and creating a nutrient rich environment during the Luteal Phase. Insufficient progesterone levels contributes to up to 40 percent of recurrent pregnancies. 

Other hormonal conditions such has Hypothyroidism, Polycystic Ovarian Syndrome(PCOS) or poorly controlled Type 1 Diabetes are also associated with infertility and miscarriages.

4 Autoimmune Disorders

About 15- 20 percent of recurrent miscarriages are associated with Antiphospholipid syndrome (APS) is an autoimmune disorder where antibodies can cause blood clots that clog up the blood supply to the placenta. Treatment for APS include low doses of aspirin. 

5. Infectious causes

Miscarriages may be associated with the presence of certain infections such as bacterial vaginosis organism called "ureaplasma," which can be detected by a cervical culture and treated with antibiotics. 

Many couples do not find the cause of their recurrent miscarriages even after testing. It is possible to have different causes for each occurrence. On the bright side, it may still be possible for women who had multiple miscarriages with an unexplained cause to have a healthy pregnancy with high rates of success.