Objective Since not all pregnancy-related complications require hospitalization midwives often provide these women with antenatal care and counseling. This study explored the experiences of midwives providing antenatal care and counseling to pregnant women with gestational diabetes mellitus (GDM). Methods Twelve midwives participated in the interview study performed in the three northernmost counties in Sweden. Grounded theory was used for analysis. Results The emerging core category was ‘Balancing fear of failure’. The unexpected disease increased the demands and the pressure. Three major conflicting situations were revealed. The midwives believed they were obligated to monitor and control the pregnancy, to initiate and motivate the necessary changes in lifestyle and provide empowering relationships with their patients. The fear of failure with these assignments made the midwives chose different strategies to manage the conflicting situations. Conclusions and practice implications The midwives described conflicting encounters providing antenatal care to pregnant women with GDM. The fear of failing to fulfill the assignments caused by the GDM made the midwives chose strategies to handle the conflicting encounters. Similar conflicting situations might be present for other health care professionals promoting lifestyle changes. The challenges might be addressed with an organization focusing on support and coaching sessions.