5450
This selective closure of the ductus arteriosus suggests that the affected twin was predisposed to hypoxia and thus was more susceptible to ductal closure in response to indomethacin exposure .
 adverse effect: ductal closure, indomethacin; adverse effect: hypoxia, indomethacin
Given options, please tell me the relationships of all the listed entity pairs.Output format is "relation1: word1, word2; relation2: word3, word4". 
Option: adverse effect 
Text: {0} 
 Entity Pairs:  ductal closure, indomethacin; hypoxia, indomethacin 
Answer:
 adverse effect: ductal closure, indomethacin; adverse effect: hypoxia, indomethacin