What are the causes of threatened miscarriage?

Threatened miscarriage refers to symptoms such as vaginal bleeding or lower abdominal pain occurring in early pregnancy, while the cervix remains closed, the fetal membranes are intact, and the size of the uterus corresponds to the gestational age. Its main causes include:

1. Embryonic factors: Chromosomal abnormalities in the embryo or fetus are the most common cause of early miscarriage, such as trisomy 21, trisomy 18, and other chromosomal abnormalities.

2. Maternal factors: These include endocrine disorders, immune system issues, uterine structural abnormalities, infections, severe chronic diseases, and unhealthy lifestyle habits.

3. Paternal factors: Chromosomal abnormalities or abnormal sperm morphology in male sperm can also lead to threatened miscarriage.

4. Environmental factors: Prolonged exposure to harmful substances, such as heavy metals, radiation, and certain chemicals, may also increase the risk of miscarriage.

In addition, a history of miscarriage, unhealthy habits such as long-term excessive smoking and alcohol consumption, and abnormal immune function, such as positive anti-phospholipid antibodies or lupus anticoagulant factors, may also increase the risk of threatened miscarriage. When symptoms of threatened miscarriage occur, prompt medical attention is necessary to identify the cause and receive appropriate treatment.