Pathophysiologic mechanisms by which adenomyosis predisposes to postpartum haemorrhage and other obstetric complications

Adenomyosis is characterized by the presence of ectopic endometrium within the myometrium. This features lead to structural changes in the surrounding myometrium and endometrium resulting also in functional changes. Alterations in the myometrium are suspected to lead to defective remodeling of spiral arteries during the early stages of decidualization resulting in altered vascular resistance and defective placentation. These alterations could play a common part in the association between adenomyosis and major obstetric complications. Latest epidemiological studies show that adenomyosis is associated with preterm birth, preeclampsia, IUGR and increased caesarean section rates, but very little is known of any underlying mechanism linking postpartum hemorrhage and adenomyosis. It is our opinion that adenomyosis may increase the risk of postpartum hemorrhage through several mechanisms that will be further clarified. Women with adenomyosis may require specific management during pregnancy and may benefit from wider understanding of the pathological mechanisms associated with this disease process.