What are the adverse effects of abortion on subsequent pregnancy?

According to research, a history of artificial abortion is associated with premature birth in subsequent pregnancy. Those with a history of artificial abortion have a higher risk of premature birth (more than 28 weeks and less than 32 weeks of gestation) in the early stages of subsequent pregnancy than those with a history of artificial abortion and a higher risk of moderate premature birth (more than 32 weeks and less than 34 weeks of gestation). A history of artificial abortion is significantly associated with spontaneous premature birth, and the relationship is dose-response. It is further pointed out that a history of two or more artificial abortions is closely associated with indicated premature birth, and the mechanism of premature birth may be related to infection and mechanical injury. A history of artificial abortion can increase the incidence of complications in subsequent pregnancy, such as threatened abortion, placenta previa, premature rupture of membranes, and fetal distress, which indirectly increases the risk of premature birth and increases the incidence of premature birth or iatrogenic premature birth.

1. The risk of threatened miscarriage in the next pregnancy after artificial abortion is significantly increased. The main reason may be that artificial abortion, especially surgical abortion, is a traumatic operation. Suction and curettage of the uterine cavity can cause damage to the endometrium. Some patients suffer from secondary infection and endometritis after surgery. Damage to the endometrium can cause poor development of the decidua in the next pregnancy. The decidua is the microenvironment of conception, and its developmental state is closely related to the success of pregnancy.

2. Artificial abortion can increase the incidence of placenta previa in subsequent pregnancy. The more times abortion occurs and the shorter the interval to the next pregnancy, the higher the incidence of placenta previa in the next pregnancy. The surgical abortion group has a higher incidence than the medical abortion group, while there is no significant difference between the medical abortion group and the control group. The possible mechanism of increased risk is that during the surgical abortion process, due to multiple suction or improper surgical operation, especially excessive negative pressure suction, the endometrium can be damaged, such as involving the basal layer of the decidua basalis, which in turn causes the decidua basalis to be underdeveloped and insufficient blood supply in the next pregnancy. In order to obtain sufficient nutrition, the placenta expands its area, extends to the lower segment of the uterus or covers the internal os of the cervix, forming a placenta previa.