AG2P1 to female has a history of previous preterm birth at 32 weeks. The percentage chances of preterm birth in this pregnancy are:
**Core Concept**
The question tests the understanding of the risk factors associated with preterm birth in a subsequent pregnancy. Recurrence risk in preterm birth is influenced by the underlying cause of the initial preterm birth, which can be categorized into two types: idiopathic (unknown) and secondary (due to a known cause).
**Why the Correct Answer is Right**
The recurrence risk of preterm birth is higher in women with a history of idiopathic preterm birth compared to those with a history of secondary preterm birth. In the case of AG2P1 with a previous preterm birth at 32 weeks, the exact cause is not specified, making it an idiopathic preterm birth. Studies have shown that the recurrence risk of preterm birth is approximately 15-20% in women with a history of idiopathic preterm birth.
**Why Each Wrong Option is Incorrect**
**Option B:** This option is incorrect as the percentage of recurrence risk is generally higher than 30-40%.
**Clinical Pearl / High-Yield Fact**
It's essential to note that the recurrence risk of preterm birth can be reduced with the use of progesterone supplementation, particularly in women with a history of idiopathic preterm birth. This is because progesterone plays a crucial role in maintaining the pregnancy and preventing preterm labor.
**Correct Answer: C. 15-20%.**