Objective: The study was performed to evaluate the course of pregnancies of HIV-infected women and their fetal outcome at 10 German reference gynecology/obstetrics departments to provide an overview of occurring complications and the rate of mother-to-child transmission (MTCT). Material and Methods: 599 pregnancies of HIV-infected mothers in the years 1999-2003 at 10 German reference gynecology/obstetrics departments were recruited for evaluation. Data collected were: mode and time of infection and time of first diagnosis, mode and week of delivery, CD4 count and viral load at diagnosis of pregnancy and at delivery, antiretroviral therapy before and during pregnancy, pregnancy complications, fetal infection and general health status. Results: 595/599 pregnancies resulted in a live birth delivered in 98.3%by cesarean section. In 55%of the pregnancies one or more complications were documented. The most common were premature contractions (21.4%) and premature rupture of the membranes (4.7%). 20.3%of the pregnant women delivered prematurely. Almost 50%of the women needed a highly active antiretroviral combination therapy (HAART). The vertical transmission rate was found to be 1.68%(10 children). Conclusions: The study shows that the rate of mother-to-child transmission (MTCT) finally resulting after therapy according to the German-Austrian recommendations for HIV therapy in pregnancy is very low (under 2%). Nevertheless, in order to achieve this outcome it is necessary to involve a specialized HIV reference center because of the very high complication rate during pregnancy. Objective: The study was performed to evaluate the course of pregnancies of HIV-infected women and their fetal outcomes at 10 German reference gynecology / obstetrics departments to provide an overview of occurring complications and the rate of mother-to-child transmission (MTCT). Material and Methods: 599 pregnancies of HIV-infected mothers in the years 1999-2003 at 10 German reference gynecology / obstetrics departments were recruited for evaluation. Data collected were: mode and time of infection and time of first diagnosis, mode and week of delivery , CD4 count and viral load at diagnosis of pregnancy and at delivery, antiretroviral therapy before and during pregnancy, pregnancy complications, fetal infection and general health status. Results: 595/599 pregnancies resulted in a live birth delivered in 98.3% by cesarean section. In 55% of the pregnancies one or more complications were documented. The most common were premature contractions (21.4%) and premature rupture of the membranes (4.7 % Of the pregnant women delivered prematurely. Almost 50% of the women needed a highly active antiretroviral combination therapy (HAART). The vertical transmission rate was found to be 1.68% (10 children). Conclusions: The study shows that that the rate of mother-to-child transmission (MTCT) finally resulting after therapy according to the German-Austrian recommendations for HIV therapy in pregnancy is very low (under 2%). Nevertheless, in order to achieve this outcome it is necessary to involve a specialized HIV reference center because of the very high complication rate during pregnancy.