Placenta Accreta Red Flags: Identifying Risks During Antenatal Care

Placenta accreta is a serious pregnancy complication that can have significant implications for both the mother and baby. It occurs when the placenta attaches too deeply into the uterine wall, making it difficult to detach after childbirth. This condition can lead to severe haemorrhaging and may require complex medical interventions, such as a hysterectomy. Recognising the red flags and risk factors of placenta accreta is crucial for early diagnosis and effective management. In this article, we will explore the red flags associated with placenta accreta, the importance of antenatal care, and the steps pregnant women can take to reduce their risk.

What is Placenta Accreta?

Placenta accreta is part of a spectrum of abnormal placental implantation disorders. In a typical pregnancy, the placenta attaches to the uterine wall and separates naturally after childbirth. However, in cases of placenta accreta, the placenta becomes abnormally adherent to the uterine lining, and its separation after birth can lead to severe complications. The spectrum includes:

• Placenta Accreta: The placenta attaches too deeply but not beyond the uterine wall.
• Placenta Increta: The placenta invades the uterine muscle (myometrium).
• Placenta Percreta: The placenta penetrates through the entire uterine wall and may attach to other organs, such as the bladder. Placenta accreta is the most common form, but all forms can pose serious risks. Studies estimate that placenta accreta affects approximately 1 in 500 pregnancies, with the incidence increasing due to rising rates of Caesarean sections and other uterine surgeries (Jauniaux et al., 2018).

Red Flags and Risk Factors for Placenta Accreta

Several key factors and warning signs can increase the likelihood of developing placenta accreta. Identifying these red flags during antenatal care can enable healthcare providers to plan for a safer delivery.

1. Previous Caesarean Sections

One of the most significant risk factors for placenta accreta is a history of previous Caesarean sections (C-sections). The more C-sections a woman has had, the higher the risk of abnormal placental attachment. Scar tissue from prior surgeries can create a weakened area of the uterine wall, allowing the placenta to invade more deeply. According to a study published in the American Journal of Obstetrics and Gynecology, women with two or more previous C-sections have an increased risk of developing placenta accreta (Silver et al., 2006). This is why careful monitoring during antenatal appointments is crucial for women with a history of C-sections.

2. Placenta Previa

Placenta previa, a condition where the placenta partially or completely covers the cervix, is another significant risk factor for placenta accreta. When placenta previa is present, the placenta is more likely to implant over scar tissue from previous uterine surgeries, which can result in abnormal attachment. Women diagnosed with placenta previa should be closely monitored through regular antenatal checkups and antenatal scans, as they have a higher chance of developing placenta accreta, particularly if they have had previous uterine surgeries.

3. Uterine Surgery or Trauma

In addition to C-sections, any previous uterine surgery or trauma, such as myomectomy (removal of fibroids), dilation and curettage (D&C), or endometrial ablation, can increase the risk of placenta accreta. These procedures can leave scar tissue, which creates an area where the placenta may abnormally attach. Women with a history of such surgeries should discuss these factors during their pregnancy clinic visits and ensure that they receive extra monitoring throughout their pregnancy.

4. Maternal Age

Advanced maternal age is another red flag for placenta accreta. Women over the age of 35 are at a higher risk of developing this condition. As women age, the likelihood of placenta previa and other pregnancy complications increases, contributing to the risk of placenta accreta. Regular antenatal care and planning for delivery in a well-equipped hospital are essential for older expectant mothers.

5. Multiparity (Multiple Pregnancies)

Women who have had multiple pregnancies (multiparous women) are at a higher risk of placenta accreta, particularly if they have a history of C-sections or other uterine surgeries. The cumulative effect of repeated pregnancies and potential uterine scarring can increase the likelihood of abnormal placental attachment.

6. Abnormally Thickened Placenta on Ultrasound

During routine antenatal scans, an abnormally thickened placenta or one with unusual vascularity may be a red flag for placenta accreta. If these findings are detected, further imaging, such as MRI, may be recommended to assess the depth of placental attachment and to prepare for a potential high-risk delivery.

Diagnosing Placenta Accreta

Early diagnosis of placenta accreta is essential for planning a safe delivery and minimising complications. The condition is usually diagnosed through antenatal scans, particularly ultrasound and, in some cases, MRI. These imaging techniques help doctors assess the position of the placenta and determine whether it has invaded the uterine wall.

Antenatal Scans and Imaging

Routine antenatal checkups often include ultrasounds to monitor the health and position of the placenta. In cases where placenta accreta is suspected, a detailed ultrasound scan can help identify abnormal placental attachment. The presence of placental lacunae (small lakes of blood within the placenta) and abnormal vascular patterns are potential indicators of placenta accreta. In some instances, MRI may be used for further evaluation, particularly when the diagnosis is unclear or if placenta increta or percreta is suspected. Early and accurate diagnosis enables healthcare providers to plan a controlled delivery, often involving a scheduled Caesarean section.

Managing Placenta Accreta

If placenta accreta is diagnosed during antenatal care, a multidisciplinary approach is usually required to ensure a safe delivery for both mother and baby. The management of placenta accreta typically involves:

1. Scheduled Caesarean Delivery: In many cases, a planned C-section delivery is recommended to reduce the risk of complications. The surgery may be scheduled earlier than a typical delivery to prevent spontaneous labour, which could lead to excessive bleeding.
2. Hysterectomy: In severe cases, particularly with placenta increta or percreta, a hysterectomy (removal of the uterus) may be necessary to prevent life-threatening haemorrhage. This decision is often made during antenatal planning and discussed thoroughly with the mother.
3. Blood Transfusions and Haemorrhage Management: Given the risk of severe bleeding, blood transfusions may be needed during or after delivery. Hospitals with experience in managing placenta accreta will have the necessary resources to address these complications.
4. Antenatal Support and Education: Women diagnosed with placenta accreta will benefit from additional antenatal support, including consultations with maternal-fetal medicine specialists and ongoing discussions about their birth plan. This support ensures that mothers feel informed and prepared for the complexities of their delivery.

Reducing the Risk of Placenta Accreta

While placenta accreta cannot always be prevented, there are steps that expectant mothers can take to reduce their risk, particularly if they have known risk factors:

1. Antenatal Care and Regular Appointments

Regular antenatal appointments are essential for monitoring the health of both mother and baby. During these visits, healthcare providers can assess any risk factors for placenta accreta, such as previous uterine surgeries or placenta previa, and plan accordingly.

2. Antenatal Education and Support

Attending antenatal classes near me can provide valuable education on pregnancy complications, including placenta accreta. Understanding the potential risks and discussing them with a healthcare provider can help mothers feel more prepared.

3. Healthy Lifestyle and Relaxation During Pregnancy

Maintaining a healthy lifestyle during pregnancy, including participating in antenatal yoga or prenatal yoga classes, can support overall wellbeing. These activities promote relaxation, which may help reduce stress and improve uterine health, although they cannot prevent conditions like placenta accreta directly.

4. Careful Consideration of Elective Caesareans

Women considering elective C-sections for non-medical reasons should discuss the potential long-term risks with their healthcare provider. While C-sections are often necessary, limiting unnecessary surgeries can reduce the risk of placenta accreta in future pregnancies.

The Importance of Antenatal Care in Identifying Red Flags

Placenta accreta is a serious condition that requires early diagnosis and careful management to ensure a safe outcome for both mother and baby. Recognising the red flags, such as previous Caesarean sections, placenta previa, and a history of uterine surgery, can help healthcare providers monitor for signs of abnormal placental attachment during antenatal care. Regular antenatal checkups, antenatal scans, and consultations with a maternal-fetal medicine specialist can ensure that potential risks are identified early. With the right care and planning, women with placenta accreta can have a safe delivery, even in high-risk situations.