Baby with an enlarged stomach


So I had my 19 week anatomy scan today and they were concerned because the baby has an enlarged stomach. They want to see if it will go away in the next month so I have to go back for another ultrasound in 4 weeks. They also had me do genetic testing to rule that rule or if it is something serious we can plan for what to do after delivery. Has anyone dealt with this before? They also told me that baby is growing fine and they aren’t to worried but they had to inform me in case he needs surgery once he’s born. This is my 4th baby and I have never dealt with this before. Thanks for any advice you can give.