[Smoking and ectopic pregnancy: is there a causal relationship?].

Tobacco smoking is often studied as a risk factor in epidemiology. The impact on fertility and pregnancy is significant. At conception, maternal smoking may have an effect on the occurrence of ectopic pregnancy. Experimental studies on hamsters show interactions between tobacco and the oviduct. These interactions may explain the role of tobacco in ectopic pregnancy. Eleven case-control studies compared smoking in two groups of women: a cases group with ectopic pregnancy, and a control group. Ten of them found a relationship between tobacco smoking and ectopic pregnancy (increased relative risk). Considering this results, we must encourage women to reduce or better to stop smoking.