Perinatal loss (PL) disrupts maternal-fetal attachment (MFA) and poses significant emotional challenges for parents and their future children. The attachment style of parents prior to the loss is crucial for their adjustment to PL. This systematic review examines "How does parental attachment (including prior maternal attachment and attachment to the deceased infant) affect bereavement outcomes (grief intensity, duration, and psychological well-being) in parents who have experienced PL, and the emotional development and attachment in their subsequent children?". A bibliographic search was conducted following PRISMA guidelines in Web of Science, PubMed, and ProQuest Central. Screening through Hubmeta included 33 studies based on set criteria. Two independent evaluators conducted the search, selection, data extraction, and quality evaluation, with excellent agreement (kappa values between 0.77 and 0.90). The sample included 6,283 women (mean age = 29.08 years), 937 men (mean age = 34.16 years), and 11,569 children. Studies assessed attachment, perinatal grief, and psychopathology (depression, anxiety, PTSD symptoms, and event impact). Individuals with insecure attachment showed poorer psychological adjustment and a higher likelihood of unresolved grief. Additionally, there is an increased tendency toward disorganized attachment, as well as behavioral issues and ADHD in one-year-old children born after pregnancies following PL. However, no differences were found in MFA to future children between mothers who have experienced PL and those who have not. This review highlights the complexity of perinatal grief, its effects on parental mental health and child development, and emphasizes the need for personalized, multidisciplinary support for affected families.