This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Miscellaneous (Obs), Subject name: Gynaecology & Obstetrics
Risk of subsequent preterm delivery with previous two preterm deliveries at < 34 weeks is? 
Select and explain. 
A. 15%, B. 20%, C. 30%, D. 40%
D: 40%
Answer: D: 40% 
Explanation: Ans. D. 40%Recurrent Spontaneous Preterm BirthsAccording to Prior OutcomeBirth OutcomeSecond Birth <=34 Weeks (%)First birth >=35 weeks5First birth <=34 weeks16First and second birth <=34 weeks41