Sudden infant death syndrome occured.

Hello doctor, My name is mounika,this is the problem occured to my cousin after her delivery.The actual delivery date was October 31st 2024 , but she was delivered a baby boy on September 25th 2024.The baby boy was died on the early hours of 11th November 2024.At that particular time of birth doctors mentioned that baby was preterm , so lungs are not fully developed.So booster injection was done to him and because of that his legs,hands and face came from blue to normal colour.But we want to know the exact reason of his death and my cousins preterm delivery.what night be the possibilities for early delivery and will that situation makes baby lungs not fully developed? Will that situation is the main cause of baby death? Why early delivery occurs in female? She is taking healthy food and went to doctor for regular checkups.For next delivery and next pregnancy is there any councelling and scan needed for her to take extra care in pregnancy?please suggest expert answer.