I drank nothing but water 3 or 4 days before the scan (this helps make sure your amnio fluid is clear & you don't have a fuzzy/dark/or gray picture), and I drank ice cold water that morning and while waiting.. they recommended juice, but I accidentally left mine in the fridge that morning. I was too excited! lol
a friend of mine swears by mt. dew too though.. she has 3 kids, and she drank it before each gender scan. she never had a problem! (((:
I'm 19 weeks tomorrow (friday) and we just found out last thursday at 17w6d.
When I went for mine I drank cold orange juice and kept a full bladder (=
Beforehand, drink lots of water. The day of the gender ultrasound, drink something sweet. I've heard orange juice really helps. I had mountain dew but it's all a personal preference.
I found out when I thought I was 16 weeks, but the baby measured 18 weeks. They say orange juice helps.