This qualitative study analyzed intergenerational relationships during a major transition: when the younger generation becomes parents. Using a modified version of the Retrospective Interview Technique, 25 new parents described unfolding changes in their relationships with one of the new grandparents (i.e., a parent or parent-in-law of the informant), beginning with the conversation when they announced the pregnancy. We found four trajectories of change. The analysis suggests that these four patterns both reproduce and challenge socially constructed expectations for new parenthood. Reflecting social expectations for substantial change, most participants’ pathways to new parent-grandparent relationships positioned birth as a central, pivotal event, a novel understanding of change in the research of turning points. In accordance with positive rhetoric in a pronatal society, nearly half of the new parents described a Peak trajectory, where childbirth was at or near the high point in the intergenerational relationship. The results also include Crisis (the inverse of the Peak trajectory), Chaotic, and Steady trajectories. Our findings add to current understandings of the ways in which social norms and expectations of childbirth may influence new parents’ intergenerational communication during this important transition.