In recent years

the incidence of placenta previa has been increasing. According to the literature

it is mainly related to induced labor

artificial abortion

cesarean section

high aging pregnancy

multipara or smoking. The placenta previa is the chief cause of bleeding in late pregnancy and threatens the lives of mother and infant

resulting in a high risk problem in obstetrics. This article studies 322 cases of placenta previa from my hospital and Dalian Obstetrics and Gynecological Hospital from January

2002 to July

2009

on the basis of clinicretrospective analysis

in order to deepen our understanding and art of treating placenta previa. The study revealed that: 1. With 322 cases of placenta previa

the incidence was 0.73%. It was higher than the incidence 0.3% reported abroad and lower than the incidence 0.94% reported in our country. The data were from sampling survey and did not prove relations between placenta previa and ages

different from the result obtained abroad in which placenta previa had relation with pregnancy ages. The outcome needs further study. But artificial abortion

induced labor

cesarean section and multipara clearly influence the incidence. The study did not analyze the relation between smoking and placenta previa

but there was external data proving that smoking was related to placenta previa; 2. Ultrasound-B is a better method for examination at present; 3. In cases of vaginal childbirth there was a higher incidence of lateral placenta previa and partial placenta previa. The conservative temporization and timely cesarean section can greatly decrease the mortality of mother and infant.