AI Insight
Approximately six days after fertilization, an embryo attaches to the uterine wall in a process called implantation, during which it begins developing both the body and placenta. This developmental stage remains the least understood period of human development and represents the point at which the majority of pregnancy losses occur. Research is working to uncover the biological mechanisms underlying this critical early phase.
Why it matters
Understanding implantation could help explain why many pregnancies fail during this early stage and potentially lead to interventions to prevent pregnancy loss. Better knowledge of placental development during implantation may also improve outcomes for pregnancy complications related to placental dysfunction.
When an embryo attaches to the wall of the uterus roughly six days after fertilization, it begins to build the body and placenta. Called implantation, this is the stage of life scientists know least about. It is also the stage when most pregnancies are lost.