Maternal Age, Prior Uterine Surgery Linked to Massive Hemorrhage in Placenta Accreta Without Prior C-Section: Study

Cesarean sections in patients with complete placenta previa (cPP) and placenta accreta spectrum (PAS) are always challenging-but what if there's no prior cesarean scar? A new study in BMC Pregnancy and Childbirth examines this overlooked population, revealing crucial risk factors for massive intraoperative hemorrhage (MIH) that every obstetrician should know.

Why This Population Is Unique

Traditionally, PAS risk is linked to uterine scars from previous cesareans. However, cPP with PAS is rising even among women without prior cesarean deliveries—often due to older maternal age or infertility treatments. Bleeding risks in these patients can be underestimated if providers rely only on ultrasound scoring systems like PASUSS.

Study Highlights: Who’s at Risk?

Researchers reviewed records of 109 women with cPP and PAS—none with prior cesarean deliveries—who underwent cesarean section from 2020 to 2024. They defined massive intraoperative hemorrhage as blood loss of ≥2000 mL during surgery. Alarmingly, 1 in 5 experienced this level of bleeding.

Through detailed analysis, the study identified three independent risk factors:

Maternal Age ≥35 years: Older mothers had over 6 times the risk of MIH.

History of Hysteroscopic Adhesiolysis: Prior surgical treatment for uterine adhesions raised risk more than fivefold.

Elevated PASUSS Score: Each point increase in the pre-op ultrasound score significantly increased hemorrhage risk.

Other factors, like diabetes, preoperative anemia, and method of conception, did not independently predict massive hemorrhage in this group.

Clinical Implications: Looking Beyond the Ultrasound

For OBs, the takeaway is clear: While the PASUSS score remains valuable, it shouldn’t be the only tool for risk assessment. A careful look at baseline characteristics—especially age and surgical history—can flag high-risk patients early. This allows for:

Early blood bank notification and preparation

Pre-op multidisciplinary planning

Patient counseling about risks and possible interventions, including hysterectomy

Why This Matters for Patients and Providers

Massive hemorrhage increases the chances of ICU admission, long hospital stays, and blood transfusions. For patients—especially those without a previous scar—being identified as high risk can mean the difference between a smooth recovery and a life-threatening complication.

Conclusion

As PAS becomes more common in women without prior cesareans, individualized risk assessment is essential. By looking beyond just the ultrasound score, clinicians can better anticipate, prepare for, and manage surgical bleeding.

Key Takeaways:

About 20% of cPP and PAS cases without prior cesarean history had massive intraoperative bleeding (≥2000 mL).

Maternal age ≥35, prior hysteroscopic adhesiolysis, and higher PASUSS scores are the strongest risk factors.

Traditional factors (diabetes, anemia, IVF) were not independent predictors in this group.

Risk assessment should combine ultrasound findings with baseline patient characteristics.

Proactive planning can improve outcomes and reduce severe complications.

Citation:

Cao P, Liu P, Ji L, Qiao C. Risk factors for massive intraoperative hemorrhage during cesarean section in patients with complete placenta previa and placenta accreta spectrum, without prior cesarean delivery: a retrospective case-control study. BMC Pregnancy and Childbirth. 2026; [Epub ahead of print]. doi:10.1186/s12884-026-09471-w