What is the primary risk associated with confined placental mosaicism?

Confined placental mosaicism is characterized by the presence of two genetically different cell lines within the placenta, with one of these cell lines often being abnormal. The primary risk associated with this condition is spontaneous abortion (SAB).

This is primarily due to the potential for placental dysfunction, which can lead to inadequate nutrient and oxygen supply to the developing fetus. When the placental cells are abnormal, they may not function properly, which can compromise fetal support and development. Consequently, this dysfunction can trigger a miscarriage, particularly in the early stages of pregnancy. Studies have shown that pregnancies affected by confined placental mosaicism have a significantly higher risk of loss compared to those without this condition.

While other risks like cholestasis, preterm birth, and uterine rupture are associated with various pregnancy complications, they are not predominantly linked to confined placental mosaicism. Thus, the significant correlation between confined placental mosaicism and spontaneous abortion clearly highlights why this is considered the primary risk.