Definition and Multiple Factors of Recurrent Spontaneous Abortion

Recurrent spontaneous abortion (RSA) is usually defined as three or more spontaneous abortions prior to 20–28 weeks gestation. RSA affects approximately 2–5% of all women of childbearing age, and it brings tremendous psychological and psychiatric trauma to the women and also results in economic burden. The causes could be female age, anatomical and chromosomal abnormalities, genetic, endocrinological, placental anomalies, infection, smoking and alcohol consumption, psychological factor, exposure to environmental factors such as heavy metal, environment pollution, and radiation.