Spontaneous miscarriage
Types of spontaneous miscarriage
Threatened miscarriage
This refers to vaginal bleeding during the first half of pregnancy and is the most common type in early pregnancy, occurring in approximately 1 in 4 to 5 pregnancies. There is a risk of miscarriage, but the likelihood of miscarriage decreases as the pregnancy progresses. Most expectant mothers experience vaginal bleeding without pain, which usually stops, and the pregnancy continues. However, when abdominal pain is present along with the bleeding, the risk of miscarriage increases.
Inevitable miscarriage
This refers to cases where a miscarriage is unavoidable due to the rupture of the amniotic membrane while the cervix is open or the bulging amniotic sac into the vagina caused by an open cervix. As the amniotic membrane ruptures, watery vaginal discharge or vaginal bleeding occurs, and uterine contractions begin, expelling the products of conception. Even if uterine contractions do not occur, if the cervix remains open for a long time, an intrauterine infection may occur.
Incomplete and complete miscarriages
A complete miscarriage occurs when all the products of conception accompanied by vaginal bleeding and significant abdominal or pelvic pain. An incomplete miscarriage occurs when some, but not all, of tissues(e.g., placenta) remain in the uterus.
Missed miscarriage(MMC)
This occurs when the fetus has died but the products of conception remain in the uterus for days or weeks while the cervix is closed without any symptoms. In most cases, there are no symptoms. It mostly happens to be discovered during a regular checkup.
Recurrent or habitual miscarriage
This refers to cases where spontaneous miscarriage occurs 3 or more times before the 20th week of pregnancy. According to another recent definition, it refers to 2 or more consecutive spontaneous miscarriages confirmed by ultrasound or pathology examination before 20 weeks of pregnancy.
Causes and risk factors of spontaneous miscarriage
Factors known to cause spontaneous miscarriage are very diverse. They can be classified into chromosomal abnormalities, endocrine(hormonal) abnormalities, immunological factors, anatomical factors, infections, and other environmental factors. Most of the spontaneous miscarriages that occur in early pregnancy are known to be caused by fetal abnormalities.
Risk Factors for Spontaneous Miscarriage
- Pregnancy of advanced maternal age
- Drinking alcohol
- Caffeine overdose
- Smoking
- Cocaine addiction
- Exposure to environmental toxins : Arsenic, carbon disulfide, polyurethane, heavy metals, organic solvents
- Infections : Herpes simplex virus, toxoplasma, cytomegalovirus, human immunodeficiency virus, parvovirus, rubella, chlamydia, mycoplasma
- Chronic diseases in pregnant women : Uncontrolled diabetes, thyroid dysfunction, and autoimmune diseases
- Intrauterine device used
- Experience of multiple abortions
- Uterine malformations : Congenital malformations, intrauterine adhesions, uterine fibroids, cervical incompetence
Prevention of spontaneous miscarriage
If any of various causes of miscarriage are due to the fetus, no matter how careful you are, you cannot prevent miscarriage. However, chronic diseases, immunological factors, anatomical factors, and environmental causes in pregnant women can be prevented through the help of a specialist and improvements in lifestyle and environment. For women who have experienced a spontaneous miscarriage, the most important way to prevent spontaneous miscarriage is to consult a specialist before pregnancy to assess the risk factors for miscarriage, improve lifestyle habits and environmental factors, and then attempt a planned pregnancy.
Lifestyle and Environmental Factors
- If you have probability of getting pregnant, it is recommended that you consult with your doctor before taking any medication.
- Because smoking during pregnancy increases the risk of spontaneous miscarriage and low birth weight, you must quit smoking before getting pregnant.
- Abstaining from alcohol when there is a possibility of pregnancy or during pregnancy is recommended.
- Avoid consuming more than the recommended daily amount of caffeine(200 mg) because excessive caffeine intake can increase the risk of miscarriage.
- Eat plenty of good-quality fruits, vegetables, whole grains, vegetable oils, and fish.
- Avoid impact to the lower abdomen.
(Source : Korea Disease Control and Prevention Agency National Health Information Portal)