This study explores the challenges faced by parenting doctoral students, focusing on their research collaboration experiences, collaborative competency, and barriers to develop collaborative competency in comparison to their non-parenting counterparts. The research employs data collected through an online survey of doctoral students at a leading research university in South Korea in 2024. The results reveal that female parenting students report lower participation in international collaborations and face greater barriers in developing global competencies compared to male and non-parenting students. However, parenting students, particularly females, exhibit higher levels of self-perceived collaborative skills and attitudes. Notably, these differences are more pronounced in non-STEM fields, with no significant sex or parenting effects observed in STEM fields. The study highlights the need for higher education institutions to ensure that research collaboration opportunities are equally accessible to all students regardless of parenting status, sex, or discipline. The findings are timely given the global concern over declining fertility rates and their potential impact on the academia.