Why do some ultrasounds require a full bladder and some don't?

[Katielady]

I'm getting an ultrasound later this morning to check out my plumbing after a recent miscarriage. It's a transvaginal ultrasound of my uterus, ovaries, and pelvic region, and I'm having it done at the hospital. They're having me drink 32 (!!!!) ounces of water an HOUR beforehand and I'm not allowed to pee. I'm a frequent pee girl and this is going to be agony for me. I remember this same hospital having me do this when I was pregnant too, which was worse.

Meanwhile, I've been to several fertility docs over the years (I have PCOS). None of them required a full bladder when I got ultrasounds in office, and they did them all the time. What gives? I would think a hospital would have more sophisticated equipment than an RE's office. I know that a full bladder makes it easier for them to see. But why do some require it and some don't? If it's not totally necessary I wish they wouldn't make me do it. And if it were completely necessary I would think that everyone would require it. Is it just that hospitals are more uptight? Is it a skill level issue, where the REs are better at knowing what they're looking at without the extra benefit of the full bladder?

I think if I had some explanation I would be less annoyed. Anyone had this explained to them?

[pokeyAC]

I'm not sure why but I've had the same experience.  When I have an ultrasound to check for follicles, they don't care about the bladder.  When I've gone in for a diagnostic ultrasound just to see if all the parts were ok, they wanted me to have a full bladder.  Then they let me go to the bathroom and they looked again.  They used internal and external probes.  One time I went for one and I didn't get the message about the full bladder, and the technician was upset that I hadn't done that.  She had to press harder, and she couldn't see what she was looking at as well.

[physics girl]

I'm curious about this as well. I'm scheduled for a diagnostic ultrasound on Monday, and I've been instructed to drink 64 oz of water an hour beforehand.
 

[Katielady]

64 oz! Holy chalupa!

As it turned out, the water was for the "over the top" standard belly ultrasound. I guess they can see everything better with a full bladder. After that she had me go pee (best pee EVER) and then she did the transvaginal US with an empty bladder. So I guess that's the difference- the fertility docs always did a TV only. I guess that's one advantage of that otherwise uncomfortable procedure.

Gah, I just hate having to go to the hospital and get any kind of test, it always sucks and always makes me feel icky.

[dejagerw]

I had a TV ultrasound with DS1. They never said anything about full or empty bladder. I didn't do anything special for that. DS1's second ultrasound at 20 weeks, I also received no instruction regarding my bladder.

DS2, for the ultrasound at 20 weeks, I was told to drink a certain amount of water so many minutes before my appointment and not to pee beforehand. Well, I drank the water, and guess what, I had to pee. So I peed and then drank a bunch more water before my appointment and they never said anything about the fullness of my bladder.

I would do your best to follow the instructions, but overall I wouldn't sweat it too much. Don't pee your pants over it. But if they want you to drink a ton beforehand do so, and I'm sure you'll be fine. Good luck!!