Frequently Asked Questions: Pregnancy
Recurrent pregnancy loss is defined as having two or more miscarriages. After three repeated miscarriages, a thorough physical exam and testing are recommended.
A small number of women (1%) will have repeated miscarriages.
Most miscarriages (about 60%) occur randomly when an embryo receives an abnormal number of chromosomes during fertilization. This type of genetic problem happens by chance; there is no medical condition that causes it. However, it becomes more common in women of increased reproductive age.
In a small number of couples who have repeated miscarriages, one partner has a chromosome in which a piece is transferred to another chromosome. This is called a translocation. People who have a translocation usually do not have any physical signs or symptoms, but some of their eggs or sperm will have abnormal chromosomes. If an embryo gets too much or too little genetic material, it often leads to a miscarriage.
Certain congenital problems of the uterus are linked to repeated miscarriages. Although there are many such disorders, one of the most common that has been associated with miscarriage is a septate uterus. In this condition, the uterus is partially divided into two sections by a wall of tissue.
Asherman syndrome, in which adhesions and scarring form in the uterus, may be associated with repeated miscarriages that often occur before a woman even knows she is pregnant. Fibroids and polyps, which are benign (noncancer) growths of the uterus, also may play a role in recurrent pregnancy loss.
Women who have certain medical conditions may have an increased risk of repeated miscarriages. Antiphospholipid syndrome (APS) is an autoimmune disorder in which a person’s immune system mistakenly makes antibodies to certain substances involved in normal blood clotting. APS is associated with repeated miscarriages and fetal deaths. Another disease that can lead to miscarriage is diabetes mellitus. In this disease, high levels of a sugar called glucose are present in the blood. Women with diabetes, especially those in whom the disease is poorly controlled, have an increased risk of pregnancy loss. Women with a condition called polycystic ovary syndrome also have an increased risk of miscarriage.
In 50–75% of women with repeated miscarriages, no cause can be found for the pregnancy loss. There may be clues about what the problem is, but there is no sure answer.
To help find the cause of repeated miscarriages, your health care professional will ask about your medical history and past pregnancies. A complete physical exam, including a pelvic exam, may be done. You may have blood tests to detect problems with the immune system. Testing may be done to help detect genetic causes of repeated miscarriages. Imaging tests may be considered to find out if a uterine problem is causing repeated miscarriages.
If a specific cause of your repeated miscarriages can be identified, your health care professional may suggest a treatment that addresses the cause.
If you have a chromosome translocation, genetic counseling may be recommended. Results of genetic testing can help clarify your options. In vitro fertilization with special genetic testing called preimplantation genetic diagnosis may be done to select unaffected embryos.
Corrective surgery may be able to increase the chances for a successful pregnancy. For example, a septum in the uterus can be removed.
Use of a medication that prevents blood clots, such as heparin, sometimes combined with low-dose aspirin, may be prescribed throughout pregnancy and for a few weeks afterward. This treatment can increase the rates of successful pregnancy in women with this condition.
What are my chances of having a successful pregnancy if I have repeated miscarriages and no cause is found?
About 65% of women with unexplained recurrent pregnancy loss have a successful next pregnancy.
Adhesions: Scarring that binds together the surfaces of tissues.Antibodies: Proteins in the blood produced in reaction to foreign substances, such as bacteria and viruses that cause infection.
Antiphospholipid Syndrome (APS): A disorder in which proteins called antibodies are mistakenly made against certain substances in the blood involved in normal blood clotting. It can lead to abnormal blood clotting and pregnancy complications, including pregnancy loss.
Autoimmune Disorder: A condition in which the body attacks its own tissues.
Chromosomes: Structures that are located inside each cell in the body and contain the genes that determine a person’s physical makeup.
Congenital: A condition that is present in a person from birth.
Diabetes Mellitus: A condition in which the levels of sugar in the blood are too high.
Eggs: The female reproductive cells produced in and released from the ovaries; also called the ova.
Embryo: The developing organism from the time it implants in the uterus up to 8 completed weeks of pregnancy.
Fertilization: Joining of the egg and sperm.
Glucose: A sugar that is present in the blood and is the body’s main source of fuel.
In Vitro Fertilization: A procedure in which an egg is removed from a woman’s ovary, fertilized in a dish in a laboratory with the man’s sperm, and then transferred to the woman’s uterus to achieve a pregnancy.
Pelvic Exam: A physical examination of a woman’s reproductive organs.
Polycystic Ovary Syndrome: A condition characterized by two or three of the following criteria: the presence of growths called cysts on the ovaries, irregular menstrual periods, and an increase in the levels of certain hormones.
Preimplantation Genetic Diagnosis: A type of genetic testing that can be done during in vitro fertilization. Tests are performed on the fertilized egg before it is transferred to the uterus.
Recurrent Pregnancy Loss: Two or more pregnancy losses.
Sperm: The male sex cell produced in the testes that can fertilize a female egg.
Translocation: An error in chromosome structure in which one part of a chromosome is transferred to another chromosome.
Uterus: A muscular organ located in the female pelvis that contains and nourishes the developing fetus during pregnancy.
If you have further questions, contact your obstetrician–gynecologist.
FAQ100. Copyright May 2016 by the American College of Obstetricians and Gynecologists
This information is designed as an educational aid to patients and sets forth current information and opinions related to women’s health. It is not intended as a statement of the standard of care, nor does it comprise all proper treatments or methods of care. It is not a substitute for a treating clinician’s independent professional judgment. Read ACOG’s complete disclaimer.