What is the recurrence risk of placental abruption in a 32-year-old gravida (number of times pregnant) three, para (number of viable births) two woman with a history of previous abruption?

Recurrence Risk of Placental Abruption

A woman with a history of placental abruption has approximately a 6% risk of recurrence in her next pregnancy, representing a nearly 100-fold increased risk compared to women without prior abruption. 1

Quantified Recurrence Rates

The most robust evidence comes from a large Dutch national cohort study of over 1.5 million pregnancies, which provides the most precise recurrence estimates 1:

• Overall recurrence rate: 5.8% in women with prior abruption versus 0.06% in women without prior abruption (adjusted OR 93,95% CI 62-139) 1
• Other studies report similar ranges: 22.2% in a smaller Japanese cohort 2 and recurrence rates varying from 13.3% to 22.8% in other series 3

Gestational Age-Specific Recurrence Risk

The timing of the previous abruption significantly impacts recurrence risk 1:

• Term abruption (≥37 weeks): Highest recurrence risk with adjusted OR 188 (95% CI 116-306) 1
• Preterm abruption (32-37 weeks): Moderate recurrence risk with adjusted OR 52 (95% CI 25-111) 1
• Early preterm abruption (<32 weeks): Lower recurrence risk with adjusted OR 39 (95% CI 13-116) 1

Recurrent abruptions typically occur 1-3 weeks earlier than the initial event 2, necessitating surveillance well before the gestational age of the prior abruption.

Impact on Maternal and Fetal Outcomes

Placental abruption carries substantial morbidity and mortality risks 3, 4, 5:

• Maternal complications: Obstetric hemorrhage, need for transfusion, emergency hysterectomy, disseminated intravascular coagulopathy, and renal failure 5
• Perinatal consequences: Accounts for 10% of all preterm births and 10-20% of perinatal deaths in developed countries 5
• Fetal mortality: Abruption involving >50% of placental surface is frequently associated with fetal death 4

Surveillance Recommendations

For women with complicated prior abruption (preterm delivery, small for gestational age, or perinatal death), initiate intensive surveillance 6 weeks before the gestational age of the initial abruption 6. For women with uncomplicated first deliveries, surveillance should begin at least 12 weeks prior to reduce recurrence risk to baseline levels 6.

Consider elective induction at 37 weeks for women with a history of term placental abruption in their previous pregnancy 1, as this group demonstrates the highest recurrence risk.

Role of Hypertensive Disorders

Hypertensive disorders increase the overall incidence of placental abruption (0.44% vs 0.16% in normotensive women, OR 2.7) 1, but paradoxically, women with hypertensive disorders have a lower recurrence risk than normotensive women (adjusted OR 0.68,95% CI 0.27-1.6) 1. This suggests different underlying pathophysiology between hypertension-associated and idiopathic abruption.

Critical Clinical Pitfalls

• Do not wait until the gestational age of prior abruption to initiate surveillance—recurrences often occur earlier 2
• Recognize that most abruptions cannot be predicted or prevented 4, but outcomes can be optimized through close monitoring and expeditious delivery when indicated
• Screen for modifiable risk factors including smoking, cocaine use, and inadequate prenatal care 7, 4
• Maintain high clinical suspicion as the diagnosis remains primarily clinical, with ultrasound having limited diagnostic value 4