International research mobility is becoming increasingly important for early-career researchers as a way to demonstrate their ambition and excellence. It can offer access to crucial research infrastructure and help expand international collaboration networks. However, the emphasis on mobility may worsen existing disparities in career outcomes, particularly for women who often face greater obstacles in moving abroad compared to men. In this study, we utilize publication metadata from Clarivate's Web of Science (WoS) to investigates whether returns to mobility are unevenly distributed between gender and the impact of any observed gender-based disparities on scientific career advancement. Preliminary results explore the gender gap in the likelihood of moving internationally, while the analysis on the returns to mobility is currently being performed by the authors.