[Epidemiology of ectopic pregnancy: incidence and risk factors].

During the past two decades, the incidence of ectopic pregnancy (EP) has doubled or tripled in many parts of the world. In France, EP currently constitutes 2 % of livebirths and 1.6 % of all reported pregnancies. These rates seem presently stable. The main identified risk factors include pelvic inflammatory disease (PID)--in particular that due to Chlamydial infection, previous ectopic pregnancy and cigarette smoking. More than 50 % of EP cases are attributable to infectious factors and cigarette smoking, suggesting dramatic effects on EP rates of appropriate prevention programs. A third risk which could be prevented is induced conception cycles, especially by Clomiphene. Other risk factors are pelvic surgery, previous EP and maternal age (especially over 35 years). Further epidemiologic research is needed to identify new risk factors, to monitor incidence rates and to evaluate the effects of public health policies on EP occurrence. French EP registers will certainly contribute to this research.