Exercising while lying on back after 12 weeks - is it ok??

[monthlymayhem]

I'm sure I read somewhere that after 12 weeks you shouldn't exercise while lying on your back as the uterus will start to weigh down on an artery and make you breathless. However I go to a legs, bums and tums class and the instructor told me that although you shouldn't do abdominal exercises on your back, you can still do other exercises such as pelvic floor lifts, etc

Can anyone help me on this? First baby and I don't want to be doing the wrong things!!

I think it's after 4 months that they say you shouldn't spend too long on your back. Basically, once you've got a big bump. You'll know if/when it starts to feel uncomfortable. I do a preggers yoga class and we definitely do a few exercises that involve being flat on back for 5 or 10 mins and I'm 34 weeks pg.

I would do it unless you find it makes you feel ill/breathless whatever.
Do what you feel comfortable with.
I lie on my back to do pilates now and then and I am 33 weeks pregnant and it's never done me any harm so far

monthlymayhem, I've heard this too, in a book called Up The Duff by Australian author Caz Cooke. By week 15, she says:

"Strictly limit exercises that involve lying flat on your back to a maximum of 2 - 3 minutes, especially from the beginning of the second trimester, and omit them altogether after you reach 20 weeks. The weight of the uterus can compress the inferior cava vena, the vein that carries the blood back to your heart from your lower parts, ultimately resulting in reduced blood flow to your head and to the baby. So if you feel dizzy and faint while on your back, turn onto your left side and rest."

But like you we do an awful lot of flat-on-back stuff at pregnancy yoga and nobody seems to mind or have heard of this. I'm really confused! Would love to get a definitive answer if anyone knows...

Thanks for the replies!

I asked my midwife today and she said that they do recommend that you don't lie on your back once you have an actual bump, so that the weight doesn't impact the main artery and make you dizzy. However she said that really you can keep doing exercises on your back and listen to your body - if you start to feel breathless or dizzy then stop, and also it can help to have a cushion under your head or shoulders so there is a slight incline.