Incidence of Placenta Percreta
Placenta percreta occurs in approximately 5% of all placenta accreta spectrum cases, with the overall placenta accreta spectrum rate in the United States now reaching 1 in 272 birth-related hospital discharges. 1, 2
Overall Placenta Accreta Spectrum Incidence
The incidence of placenta accreta spectrum (which includes accreta, increta, and percreta) has increased dramatically over recent decades 1:
- Historical rates (1970s-1980s): 1 in 2,510 to 1 in 4,017 pregnancies 1
- 1982-2002: 1 in 533 pregnancies 1
- Current U.S. rate (2016 data): 1 in 272 birth-related hospital discharges 1
This represents more than a 10-fold increase over four decades, directly correlating with the rising cesarean delivery rate 1, 3
Placenta Percreta Specifically
Placenta percreta represents the most severe form of abnormal placental adherence and accounts for approximately 5% of all placenta accreta spectrum cases. 2 This means percreta invades through the entire myometrium and potentially into extrauterine tissues like the bladder, distinguishing it from accreta (adherent to myometrium) and increta (invading into myometrium). 2, 4
Risk-Stratified Incidence in High-Risk Populations
The incidence varies dramatically based on specific risk factors, particularly the combination of placenta previa with prior cesarean deliveries 1:
Without placenta previa:
- General population baseline: approximately 0.3% with one prior cesarean 1
- Increases to 6.74% with five or more prior cesareans 1
With placenta previa present (the critical risk factor):
- No prior cesarean: 3% risk of accreta spectrum 1
- One prior cesarean: 11% risk 1
- Two prior cesareans: 40% risk 1
- Three prior cesareans: 61% risk 1
- Five or more prior cesareans: 67% risk 1
Placenta previa overlying a cesarean scar is present in 49% of all accreta spectrum cases, making it the single most important identifiable risk factor. 5
Additional Risk Factors Affecting Incidence
Beyond cesarean delivery and placenta previa, other factors increase risk 1:
- Advanced maternal age 1
- Multiparity 1
- Prior uterine surgeries including myomectomy with endometrial cavity entry 1, 6
- Prior curettage procedures 1
- Asherman syndrome 1
- In vitro fertilization 7
Clinical Implications
Given that approximately 50% of women with accreta spectrum who wait beyond 36 weeks require emergent delivery for hemorrhage, and that percreta carries the highest morbidity and mortality risk within the spectrum, early identification through ultrasound screening of high-risk patients is critical. 5, 2 The dramatic increase in incidence means that any woman with placenta previa and prior uterine surgery should be considered high-risk and referred to a level III or IV maternal care facility with multidisciplinary expertise. 5, 8