Morbidly adherent placenta is a serious pregnancy complication where the placenta abnormally attaches to the uterine wall. Unlike a normal delivery where the placenta detaches after childbirth, in this condition, it remains firmly attached. This abnormal attachment can lead to significant health challenges for both the mother and the developing baby, requiring specialized medical attention.
Understanding Morbidly Adherent Placenta
Morbidly adherent placenta, also known as placenta accreta spectrum, describes an abnormal invasion of the placenta into the uterine wall. This condition is categorized into three types based on the depth of placental invasion.
Placenta accreta is the least severe form, where the placental tissue adheres to the uterine muscle without invading it. Placenta increta represents a deeper invasion, with the placental tissue growing into the uterine muscle itself. The most severe form is placenta percreta, where the placental tissue penetrates through the entire uterine wall and can even extend into nearby organs, such as the bladder or bowel. The severity of complications increases with the depth of invasion.
Factors Increasing Risk
Several factors increase the risk of developing a morbidly adherent placenta. A primary risk factor is a history of prior cesarean deliveries, with the risk rising significantly with each subsequent C-section. For instance, the risk can be around 3% for a woman with one prior C-section, increasing to over 50% for those with three or more.
Other uterine surgeries, such as myomectomy for fibroid removal, also contribute to the risk by creating scarring or damage to the uterine lining. Additionally, advanced maternal age, a history of placenta previa (where the placenta partially or completely covers the cervix), and previous uterine instrumentation like curettage are associated with a higher incidence of this condition.
Potential Dangers
Morbidly adherent placenta poses several serious health risks, primarily to the mother. The most significant danger is massive hemorrhage during or immediately after delivery. Since the placenta does not separate normally, attempts to remove it can lead to severe, uncontrollable bleeding.
This extensive blood loss often necessitates blood transfusions, with approximately 90% of cases requiring them. In severe instances, a peripartum hysterectomy, the surgical removal of the uterus, may be performed immediately after delivery to control life-threatening bleeding. Risks to the baby include premature birth, as early delivery is often planned to manage the condition.
Identifying the Condition
Diagnosis of morbidly adherent placenta often begins during prenatal care. Ultrasound imaging is the primary diagnostic tool. Specific ultrasound markers, such as multiple vascular lacunae (spaces) within the placenta, a loss of the normal clear zone behind the placenta, or an abnormal appearance of the uterine wall near the bladder, can indicate its presence.
If ultrasound findings are inconclusive, magnetic resonance imaging (MRI) may provide a more detailed assessment of the placental invasion. Despite these methods, the condition is not always fully recognized before delivery and may only become evident during a C-section when the abnormal placental attachment is directly observed. Early prenatal diagnosis can significantly improve outcomes.
Managing the Condition
Management of morbidly adherent placenta requires a highly coordinated, specialized approach involving a multidisciplinary team. This team typically includes obstetricians, surgeons, anesthesiologists, and neonatologists, all working together to plan and execute the delivery. The goal is to minimize complications, especially severe bleeding.
Management involves a planned, controlled delivery, often via a cesarean section between 34 and 35 weeks of gestation, following corticosteroid injections to mature the baby’s lungs. If the placenta cannot be safely removed from the uterine wall, a hysterectomy is often performed immediately after the C-section to control hemorrhage. Throughout the process, careful monitoring and preparation for significant blood loss, including the availability of a large blood bank, are essential.