According to the guidelines and the manufacturer's information, pregnancy is a contraindication for sclerotherapy with Polidocanol. However, in some cases sclerotherapy has been conducted in a period when the pregnancy is not known by the patient. When pregnancy is diagnosed, patients and gynecologists often ask the phlebologist if there is an indication for the interruption of pregnancy. Up to now, there is only rare information on sclerotherapy, polidocanol and pregnancy. Current knowledge is summed up in this article together with case reports. The existing case reports and mainly retrospective case series on intended or accidentally conducted sclerotherapy with common sclerosants and doses show no increased risk for the mother and the unborn child. However, in view of the limited literature data available and the high probability for spontaneous regression of varicose veins postpartum, sclerotherapy should be avoided in pregnancy, if possible. Conservative measures during pregnancy or an elimination of varicose veins before pregnancy should be preferred. In single cases e.g. painful genitoanal varices, the use of sclerotherapy can be helpful even during pregnancy. Thereby, a very thorough clarification of the mother with a final written consent and an implementation according to the guidelines are especially important. According to the current data, there is no reason for an interruption after a sclerotherapy that has been conducted during undetected pregnancy.