Placenta accreta spectrum is an abnormal adherence of the placenta to the uterine wall that can lead to significant maternal complications. The placenta invades more deeply than normal into the muscle wall of the uterus, and occasionally grows through the full thickness of the wall outside of the uterus. There are varying depths the placenta can attach abnormally: Placenta Accreta, Increta and Percreta at the deepest. In a standard delivery the placenta is expelled or removed from the woman to allow the uterus to contract and prevent bleeding. Maternal complications can occur due to severe haemorrhaging when the retained placenta in the uterus prevents this uterine contraction and often requires a blood transfusion.
The incidence of placenta accreta has increased recently due to the increasing caesarean delivery rate. Detection in pregnancy is via ultrasound along with risk factors including placenta previa and prior caesarean delivery and can aid in delivery planning and improved outcomes (Wortman, 2013).
Risk factors for developing Placenta Accreta
- Previous caesareans
- Placenta praevia
- Fibroid resections
- Uterine surgeries
- Advanced age
- More births
- Severe pelvic pain
- Absence of menstruation
**During pregnancy there are no symptoms
- Caesarean hysterectomy (removal of the uterus at time of caesarean)
- Delayed hysteroscopic resection (removal of placenta after delivery which can take multiple surgeries in the attempt to maintain the uterus and fertility)
- Experimental caesarean technique listed below;
Chen et al 2016 conducted research on a technique of using two parallel transverse incisions to the uterus to remove the entire placenta with women who were diagnosed with placenta accreta in pregnancy. One incision in the upper segment of the uterus was used to remove the neonate and the lower incision was used to remove the placenta. This technique helped prevent postpartum haemorrhage and all of the women who had ceased breastfeeding had normal menses return. There is a concern, however, with subsequent pregnancies after this technique as it has not been studied.
Studies have shown that women with placenta previa but no prior caesarean deliveries, the risks for placenta accreta is 5%. However, this risk for accreta increases to 20% in patients with 1 prior caesarean delivery plus placenta previa in the current pregnancy. For patients with placenta previa plus 2 or more prior caesarean deliveries, the risk of placenta accreta is 40% or greater. When placenta accreta is suspected, the imaging information should be considered as an adjunct to the clinical history and the intraoperative findings. Ultimately, the diagnosis of placenta accreta is a surgical diagnosis (Nageotte, 2014).
Retrospective research of pregnancies following conservative management of placenta accreta have reported good fertility rates and pregnancy outcomes but with an increased rate of recurrent placenta accreta. Successful conservative treatment for placenta accreta does not appear to compromise subsequent fertility or obstetrical outcome (Sentilhes, 2010).