There are several causes of partial gravidity: first, it is related to dietary habits and nutrition. The lack of folic acid during the embryonic angiogenesis stage affects thymidine synthesis, causing a lack of blood vessels in the placental villi, resulting in the symptoms of partial gravidity. Secondly, partial gravidity occurs due to viral infection. Thirdly, it is related to the endocrine disorder in pregnant women. Generally, women in their twenties to forties with incomplete or declining ovarian function are prone to partial gravidity. Fourth, abnormal development of the female ovum may also lead to the possibility of partial gravidity. Therefore, it is important to take folic acid supplements and pre-conception checkups during pregnancy preparation, and pay more attention to diet and lifestyle habits after pregnancy.