Objective: This research article investigates the relationship between parenthood and wages, considering the partner's gender and the influence of employers on wage trajectories for birth and non-birth mothers and fathers. Background: It offers a novel examination whether the gender of the partner affects the wage outcomes for birth mothers and explores the differential impact of employers on wages for birth and non-birth mothers, using Dutch register data. Method: Utilizing OLS regression, Heckman selection, and fixed-effects models, this study focuses on all Dutch couples who had their first child between 2008 and 2014 in the Netherlands, from two years prior to the birth until two years after birth. Results: Consistent with human capital theory, the findings reveal a consistent and unfavourable wage development for birth mothers, regardless of whether they are in same-sex couples or different-sex couples. The wage development for non-birth mothers in female same-sex couples resembles that of fathers, showing a more positive trajectory compared to birth mothers. Furthermore, the analysis indicates that employers do not differentiate in their treatment of birth and non-birth mothers, suggesting that biological constraints associated with motherhood impact wages of birth mothers, while both their male and female partners’ wages do not decline. Conclusion: The study contributes to the existing literature in family sociology, highlighting the need for policies and interventions that address the specific challenges faced by birth mothers in the labor market. - Appendix: https://ubp.uni-bamberg.de/jfr/index.php/jfr/article/view/960/765 ; Fragestellung: Diese Studie untersucht den Zusammenhang zwischen Elternschaft und Gehalt, wobei sowohl die Rolle des Geschlechts des Partners als auch der Einfluss des Arbeitgebers auf die Lohnentwicklung von leiblichen - und nichtleiblichen Müttern und Vätern berücksichtigt wird. Hintergrund: Die Studie bietet eine neuartige Untersuchung der Frage, ob das Geschlecht des Partners ...