The Fourth Trimester of Pregnancy

Through a unique blend of scientific research, social insight, and empathetic reflection, Bayot explores the postpartum period as a fourth trimester—a vital phase of adaptation for the new parents and their baby, months of transformation that connect pregnancy to parenthood.

Drawing on contemporary research in physiology, psychology, anthropology, and neuroscience, Bayot sheds light on the profound physical, hormonal, and emotional changes that occur after birth. She shows how the mother’s body continues to evolve—through lactation, hormonal readjustments, and sensory attunement—to meet the baby’s developmental needs. The book details the biological synergies between mother and infant, such as the hormonal dialogue involving oxytocin, prolactin, and endorphins, and how these shape the foundations of attachment, recovery, and well-being. But this book also centres relationships, examining how this period affects both parents and the family dynamic, exploring the shifting roles of fathers and partners, the need for social support, and the cultural expectations that weigh on new parents. She highlights how industrialized societies, with their fast-paced and efficiency-driven rhythms, often clash with the “organic time” of early parenthood—a time that requires slowness, patience, and surrender to the baby’s natural cycles. Each chapter blends practical guidance with reflective passages that invite readers to reconnect with their own bodily intelligence and relational sensitivity. Bringing visibility to a stage of life that is biologically complex, psychologically demanding, and culturally undervalued, and developing a new concept of ‘degestation’, Bayot gives legitimacy to the emotions, vulnerabilities, and transformations of early parenthood.

This text is an important resource for student and practising midwives, nurses, psychologists, doctors and doulas, looking to develop their skills and understanding in working with new parents and babies. Parents themselves, and new mothers in particular, will find in these pages valuable guidance for navigating this intense period of their lives.