Spontaneous end of pregnancy before the fetus reaches its 20th week of growth is known as a miscarriage. It is also referred to as spontaneous abortion caused by natural events. Studies show that about 15% of the reported pregnancies lead to miscarriages, and most of them are within the first trimester. Miscarriages after 20 weeks of pregnancy are known as late miscarriages.
Potential causes of a miscarriage include:
- Chromosomal abnormalities – Most of the miscarriages that happen in the first trimester of pregnancy are caused by chromosomal abnormalities in the fetus. Presence of abnormal chromosomes in the developing fetus triggers miscarriages, especially during the first three months. Miscarriages during the second trimester are less common. Risk of fetal chromosomal abnormalities increases considerably with increasing age of the mother. Women above the age of 35-years-old have greater chances of a miscarriage.
- Diabetes during pregnancy – If not treated adequately, diabetes may increase the chances of miscarriage and birth defects in babies. Regulating blood sugar levels is very important for having a healthy baby.
- Infections – A number of infections that affect the mother during pregnancy increases the risk of miscarriage as the organisms may infect the developing fetus as well. Infections by Listeria, Toxoplasma, parvovirus or herpes simplex virus may all lead to miscarriages.
- Hormonal factors – Many hormonal issues, like thyroid problems also may lead to miscarriage.
- Abnormalities in the uterus – Abnormalities, like presence of a uterine septum and fibroids also lead to increased risk of miscarriages. These changes may affect implantation or blood supply to the fetus leading to spontaneous loss of the fetus at an early stage.
- Early opening of cervix – Cervix opening widely at an early stage may induce miscarriage without any pain.
- Auto immune diseases – Diseases like lupus and antiphospholipid antibody syndrome are associated with increased risk of fetal loss.
Some of the factors that increase the risk of miscarriage include:
- Kidney disease
- Congenital heart disease
- Exposure to radiation and toxic substances
- Certain medications
- Invasive procedures, like amniocentesis and chorionic villi sampling
- Smoking, drug abuse, and use of alcohol
Contrary to common belief, exercise and working does not increase the chances of losing a fetus at an early stage. Women who had premature deliveries earlier, and those who had obstetrical issues are generally advised to refrain from strenuous exercise and working to reduce the chances of spontaneous abortion.
- Miscarriages can commonly occur naturally, without notice.