Which risk factor has the highest odds ratio for placental abruption?

The risk factor associated with the highest odds ratio for placental abruption is a history of abruption. This is primarily due to the fact that women who have previously experienced placental abruption are at an increased risk for recurrence in subsequent pregnancies. The physiological and anatomical changes that may have predisposed the placenta to abruption in the first instance are likely still present or could be exacerbated in future pregnancies, making this factor particularly significant.

Understanding this concept is critical for clinical practice, as it necessitates close monitoring and management of pregnancies in individuals with a history of placental abruption to mitigate risks to both the mother and the fetus. The recurrence risk is particularly high, making it essential for healthcare providers to be aware of this history when assessing the patient's overall risk profile during subsequent pregnancies.