Excessive weight gain during pregnancy is a significant health issue, as it can lead to complications for both the mother and the newborn. This study focuses on understanding the key factors that contribute to excessive weight gain during pregnancy. These factors include physical activity levels, nutritional habits, and pregnancy-related anxiety. The study aims to identify which of these factors has the most significant impact on excessive gestational weight gain. It involves pregnant women in their third trimester who are being monitored at Gebze Fatih State Hospital. The study is important as it could help improve pregnancy care by identifying ways to manage weight gain effectively, thereby reducing potential health risks for both mother and baby. Participants in this observational study will be asked to complete a series of assessment tools. These include a form to capture demographic details, the Pregnancy Physical Activity Questionnaire (PPAQ) to evaluate physical activity levels, a nutritional status assessment form to examine dietary habits, and a pregnancy-related anxiety questionnaire to measure anxiety levels associated with pregnancy. All participants will receive detailed verbal and written information about the study and will be required to provide written consent before enrollment. The collected data will be analyzed to determine the relative impact of physical activity, nutritional status, and pregnancy-related anxiety on excessive gestational weight gain. The primary outcome of the study is to determine the number of participants with excessive gestational weight gain, as classified by the Institute of Medicine (IOM) recommendations adjusted for pre-pregnancy body mass index.