From the Guidelines
Placental abruption is most common in the third trimester of pregnancy, particularly between 24 and 40 weeks of gestation, affecting approximately 1% of pregnancies 1. When considering the timing of placental abruption, it's crucial to understand that the risk increases as pregnancy progresses, with the highest risk occurring near term.
Key Factors
- The condition involves premature separation of the placenta from the uterine wall before delivery, which can compromise maternal and fetal blood supply 1.
- Symptoms typically include vaginal bleeding, abdominal pain, uterine tenderness, and contractions.
- Risk factors include maternal hypertension, preeclampsia, previous abruption, trauma, cocaine use, cigarette smoking, advanced maternal age, and multiple gestations.
Importance of Diagnosis
- Ultrasound (US) imaging, particularly transabdominal and transvaginal US, is vital for diagnosing placental abruption and guiding management 1.
- A central abruption is associated with worse perinatal outcome than a marginal separation of the placenta, highlighting the need for accurate and timely diagnosis 1.
Clinical Approach
- Women with risk factors should receive close prenatal monitoring.
- Anyone experiencing symptoms should seek immediate medical attention as placental abruption constitutes an obstetric emergency requiring prompt evaluation and management.
From the Research
Placental Abruption Frequency
- Placental abruption is a condition where the placenta separates from the uterus before the baby is born, and it occurs in approximately 0.4-1% of pregnancies 2.
- According to a study published in 2023, nearly half of placental abruptions occur at term gestations, which is defined as 37 weeks of gestation or later 3.
- Another study found that the frequency of placental abruption was 3.75% among 2610 deliveries, with the majority of cases occurring between 26-30 years of age and in women who were second, third, or fourth gravida 4.
Gestational Age and Placental Abruption
- The mean gestational age at the time of placental abruption was 34 +/- 4.21 weeks, with 51% of deliveries occurring preterm (before 37 weeks) and 49% occurring at or after 37 weeks of gestation 4.
- A study published in 2015 found that gestational age at delivery was a significant risk factor for perinatal mortality, with a perinatal mortality rate of 42% in patients who delivered prior to 30 weeks of gestation compared to 15% in patients who delivered after 30 weeks of gestation 5.
Risk Factors for Placental Abruption
- Risk factors for placental abruption include parity, gestational age, hypertension, substance abuse, smoking, intrauterine infection, and recent trauma 4, 2, 5.
- A study published in 2011 found that placental abruption is one of the leading causes of vaginal bleeding in the second half of pregnancy, and it is associated with poor maternal and fetal outcomes 2.