If your baby could be born with a disease would you get your baby tested during your pregnancy?

My daughter has Tay Sachs disease (a genetic disease which can't be cured and is eventually fatal). She's beautiful and started out normal like any other child but then began showing symptoms. She's over four now and is a very sweet child but experiences a lot of involuntary movements and is now unable to walk properly and can't control her bodily functions at all. She's lost a lot of weight and awareness too. I have another daughter who's normal, and I didn't know my partner and I both carried the gene for the disease until after I had her, she was diagnosed when I started noticing her unusual behaviors/symptoms. I'm pregnant again though this pregnancy was not exactly planned for, I got pregnant while on birth control. And basically I'm afraid this baby will be born with Tay Sachs. I was wondering if you were pregnant and you and your partner were carries for a serious genetic disease would you want to find out if your baby had the disease during your pregnancy? What would you do? What does your religion teach about prenatal testing? (I'm not really a religious person, I'm just wondering)