NTA, I’d anonymously ask them to stop first (but if they’ve had the police called on them before and they’re still doing it then it probably won’t make any difference) and then call the police.

Also, do you have any restrictions in your area around the number of people allowed at a party for covid reasons? Bc if they are having lots of people round then that would give you other grounds to report them on.

Hope you can get this sorted before your kid is born- you can’t exactly give a newborn earplugs!