A groundbreaking UCLA study has uncovered a critical link between scar healing and a dangerous pregnancy complication known as placenta accreta spectrum (PAS). This condition, once rare, now affects thousands of pregnancies annually, making it a leading cause of maternal mortality. The mystery surrounding its occurrence has deepened, but new research offers a glimmer of hope and understanding.
PAS occurs when the placenta grows excessively into the uterine wall, failing to detach after birth. This can lead to life-threatening bleeding and often necessitates a hysterectomy. The primary risk factor is a history of cesarean delivery, as scarring from previous cesarean births can alter the placenta's attachment in subsequent pregnancies.
The UCLA Health-led study suggests that the healing process of scar tissue holds the key to unraveling the complexities of PAS. Dr. Yalda Afshar, an associate professor and co-director of the UCLA Health Accreta Care Program, emphasizes that the issue lies not with the placenta's abnormal growth but with the changes scarring induces in the uterine structure, increasing delivery risks.
Published in the American Journal of Obstetrics and Gynecology, the study utilized surgical specimens, a mouse model, and an innovative "accreta-in-a-dish" system. Through advanced 3D imaging, researchers discovered that tangled or irregular collagen at old uterine scars disrupts the normal boundary between the uterus and placenta, creating an environment conducive to abnormal placental attachment and high-risk deliveries.
Researchers collected samples from patients with PAS and those with accreta risk factors but without PAS. Their findings revealed that persistent inflammation and immune cells called macrographes interfere with normal scar remodeling, resulting in abnormal collagen architecture that promotes abnormal placenta attachment.
"Not all scars heal alike," Afshar explains. "This research sheds light on why some patients with prior cesarean deliveries develop PAS while others do not. It also points to potential methods for identifying risk earlier, either before pregnancy or in the early stages of gestation."
The article, titled "Placenta accreta spectrum: disrupted collagen architecture at a previous scar is a defining characteristic of placental adherence," by Kashani Ligumsky, Lior et al., provides further insights into this groundbreaking research.
