Problems with inlaws and expecting a baby. what to tell the kid?

a few yrs back, my MIL got into an argument with my DH. they stopped talking, and later my MIL said that my husband can come to their house, but that I am not allowed in their house. we were amazed because I had nothing to do with the argument and never misbehaved with my MIL or any other in-law. but they never wanted my husband to marry me in the first place, and they took this opportunity to gang up against me.. as a result my husband said he'd only go to his parents house if I am allowed there. so my in-laws stopped meeting us. the only way they'd reconcile now is if my husband leaves me. now its been almost 4 yrs and i'm pregnant with our 1st baby. I've been thinking, what if our kid ever ask us about his dad's family, what should be say or do about it? has anyone been in a similar situation?