Thickening heart valve on anatomy scan?

Please if anyone has had this happen share your story with me. 38 weeks pregnant. Just got results back from our 3rd high risk anatomy scan that had nothing to do with a heart problem and this showed up so we are going tomorrow for our 4th one. I didn't get much info from my Dr except it looked liked a thickening part on his heart and could cause complications when he was born (if) it's there. She just kind of said it meant that his heart would have to work twice as hard to pump blood and that's it. I wasn't told what kind of complications could happen at birth, if surgeries was something that would come along with this or anything else.