What causes a miscarriage?Chromosomal abnormalities account for 50 percent of all miscarriages in the first trimester. Two sets of chromosomes, which determine a baby’s physical attributes, come together, but this process isn’t always perfect. An egg or a sperm may have more or fewer than the typical number of chromosomes. As the fertilized egg grows into a fetus, the cells divide and multiply several times, during which abnormalities that lead to a miscarriage may occur. It isn’t entirely understood why some chromosomal abnormalities cause a miscarriage and others result in babies born with genetic conditions, like Down Syndrome. One theory is that the mother’s immune system recognizes a problem in the fetus’s genes and opts to end the pregnancy. Another idea is that the specific gene problem results in the fetus’s inability to keep growing. Beyond chromosomal abnormalities, several other factors may cause a miscarriage. Diseases and infections may play a role. If you have an infection, severe kidney disease, uncontrolled diabetes, thyroid disease, immune system disorders, or congenital heart disease, you may be at an increased risk for miscarriage. If you have a TORCH infection, which can be passed to the fetus during pregnancy, childbirth, or through breast milk, you may also be at a heightened risk for a miscarriage. TORCH infections include toxoplasmosis, HIV, syphilis, parvovirus B19, varicella, Zika virus, rubella, cytomegalovirus, and herpes simplex virus.
Miscarriage is often incorrectly labeled as preventable, which leads to many women feeling like they did something wrong.Advanced maternal age is considered to play a role in pregnancy loss. After the age of 35, the pregnancy is labeled as geriatric. As a woman’s age increases, the quality of her eggs typically decreases. Those older eggs are more likely to cause chromosomal abnormalities. You’re also more likely to experience chronic medical conditions as you age. A geriatric pregnancy increases the risk not only for miscarriage but also for other factors like genetic disorders, preeclampsia, and low birth weight. Although there are fewer studies on how paternal age affects pregnancy, it’s believed that these risk factors increase for men over the age of 40. A miscarriage may also be caused by hormonal imbalances, uterine abnormalities, or an incompetent cervix, which opens too early in a pregnancy. Radiation or certain medications may also pose a risk, as does severe malnutrition. Although certain lifestyle factors may result in a pregnancy loss, such as drinking alcohol, smoking, or doing recreational drugs, miscarriages are most often not caused by something the mother did. The mother’s mental health is often blamed for miscarriages, especially regarding her stress level, but there is no proven link between stress and miscarriages. Most often, miscarriages simply happen, and there’s little that can be done to prevent them.