Is it still rape if a man is drunk and a sober woman takes advantage of him?

My husband is dealing with a woman that will not leave him alone. She is now claiming that she is having his baby. He said that he has never touched her. But he did go out with his cousin to a local restaurant that serves alcohol and she showed up. He said that she kept hounding him and so he went outside to the smoking deck and never wen back into where she was. He said that he didn't remember leaving or anything that happen hat night because he had gotten very drunk. He didn't een remember getting back to his cousins house.He is afraid that she took advantage of him in his very drunk state of mind just so she could get pregnant by him to make sure she still has ties with him. If she was sober and my husband was so drunk he don't remember leaving the restaurant can he file rape charges against her if she has the baby 9 months after the time frame of that night?