It's not for certain that you'll be asked any clinical questions. I wasn't asked any at my interview for PICU as a new grad. The interviewer knows you are a new graduate and will not expect you to have a huge knowledge base related to NICU/OB clinical skills. What you learned in school should be enough of a base to prepared you for any clinical questions that would be appropriate to ask a new graduate.
Remember that the thought process is more important than the end answer. If the interviewer asks a clinical question, they don't necessarily want you to know the answer off the top of your head. Rather, they want you to show that you have the critical thinking skills and the resources to figure it out- or to know where to go to look. They don't want to see you taking random shots in the dark or guessing- as that shows that you may not be willing to admit that you don't know something and make unsafe practice decisions. So if you're asked a clinical question, talk it out loud.
Interview question: "You're taking care of an antepartum patient being monitored for premature labor. When you enter the room the patient states they feel like something is coming out of them. Upon assessment, you find what appears to be the umbilical cord protruding from the patient. What do you do?"
Your reply: "While I've never encountered a situation like this, I know that a prolapsed cord (if you know the medical term- use it) is an emergency situation. The cord brings blood and oxygen to the baby and when it has come out of the uterus, it can become compressed and blood and oxygen to the baby will be cut off. The patient should be positioned to try to relieve as much pressure on the cord as possible (even if you don't know the exact positions, this states you know the rational for what you're doing) and I would try to get a fetal monitor on as soon as possible. I would also immediately call for help from other staff in order to address this emergency and get the patient ready for an emergency cesarean section (this shows that you recognize that the situation is emergent and you know you need extra help). I'd also try to explain the situation very simply to the patient while trying to keep her as calm as possible.
So in the above example, you might not know that the patient needs to go into reverse trendlenburg or a hands and knees position, or that the nurse can insert a gloved hand into the vagina to attempt to push the presenting part of the fetus off the umbilical cord, it does show that you can recognize an emergency, know when you need extra help, and assess the situation well enough to make decisions- and understand why you're making those decisions.