Background and Objective: Although pregnancy is a pleasurable period for most women, but generally, it is a stressful period with physical and psychological changes. Mothers’,worries during pregnancy are associated with more problems in pregnancy. Improving well-being is one of the important goals for pregnant women. The aim of this study was to explore the concerns of pregnancy in nulliparous women. Materials and Methods: This qualitative study was performed through the conventional content analysis via using Granhiem and Landman method. Data were collected through semi-structured interviews with 24 primiparous mothers in Kashan and data saturation was obtained. Data analysis was performed using the MAXQDA 10 software. Results: Data analysis led to two categories and subclasses. The first category was the mother’, s concerns about her HEALTH during pregnancy, which included the following categories: changes in physical and mental conditions during pregnancy and coping with its, HEALTHy childbirth, family and social support, role playing as a spouse, and Parental role challenges. The second category was the mother’, s concerns about the HEALTH of fetus in pregnancy, which included the following categories: Unpleasant thoughts about fetal formation, responsibility for fetal HEALTH, and Fear of fetal injury during pregnancy and childbirth. Conclusion: Pregnant women during pregnancy suffer from a number of concerns about their own HEALTH and their fetus, which can threaten the HEALTH of both. Therefore, it seems that mothers ‘, HEALTH care providers can help mothers to experience a safer pregnancy by reducing negative thoughts by holding training classes.