In any event, the doctor said that their hearts are "GORGEOUS!" So that's good news! I got to watch their hearts quite a bit (which is really really amazing by the way... it's crazy how much you can see on just a 2D ultrasound), so I definitely agree that their hearts look gorgeous!
They also took measurements to make sure the babies are growing properly (and at the same rate). There was around a 5% difference in size, which is totally normal and within the margin of measurement error, so that's more good news! Both babies are now over 1 pound! Baby A is in the 34th percentile for size and baby B is in the 40th percentile. I was a little concerned about them being less than 50% (I expect them to excel, damnit!), but the doctor assured me that there is nothing to be concerned about at all. Because they are growing at the same rate and they have plenty of fluid, the smaller size doesn't mean anything bad. I have nonetheless vowed to myself that I will eat EVEN MORE (if that's possible). Boris also reminded me that at this gestational age, twins tend to be smaller on average than singleton babies, so they are probably measuring exactly right for twins. I guess if the doctor who has seen every complication and problem child isn't worried, I won't be either.
At the end of the appointment, I asked her, "with all of this in mind, what do I currently need to be worried about?" She said nothing -- enjoy this lull where there is nothing to stress out about. So I will!
Here are some pictures of the babies at 23 weeks. They are way too big to get the whole baby in a single shot now. In fact, in order to measure them, did you know that they don't measure from head to bum anymore? Instead they measure their head, abdomen, and femur. An algorithm guesses their size and weight based on that. Fun fact / lesson for the day :)
Isn't the nose kind of adorable??