I’m 24 weeks and have a fetal echo in a couple of weeks, based off the facts we conceived twins through IVF. I guess (and I’m only saying what my OB said) that there can be heart issues when conceiving through IVF, so it’s just to make sure the hearts are growing and pumping normally (that’s the first Ive ever heard of it, but tbh if there was any issue I feel that the anatomy scan would’ve shown something.)