DOG problems during pregnancy

So we have a 2 1/2 labradoodle that we love. He has so many great qualities (smart, the nose of a hunter, sweet, knows tricks, cuddles, etc), but has many burdening qualities has well (barks at other dogs on leash, jumps on people, wild around kids, separation anxiety, occasionally growls at children, etc). Now I love this dog. He's never had a bad experience with a child besides the fact that he is so rough and wild around them (he would tackle them as if they were puppies when he was a puppy). I was worried he wouldn't know how to treat our child but I had hope. The other day my niece was petting him while being intentionally supervised...he got nervous and growled and bit her, broke skin and needed a butterfly stitch. He is not a bad dog, but he's the type of dog that appears isn't the friendliest with children due to nervousness and needing to be in control ( he could sniff or lick her but if she goes to him he's nasty). Being that he is and has been in training obedience classes, I have hope they will fix the previous issues I spoke on, but as far as being able to be pet by a kid while being supervised...if he can't do that I'm seriously worried and I can't risk that again with my sisters kids let alone my own one day. This awesome dog would spend majority of his life being tied up or in a room whenever a baby is out..My husband and I agreed he is a great dog but may not thrive in a house such as our own where we'd like as lot of kids. Our breeder agreed to happily research some empty nesters or farms that have been searching for labradoodle and don't have kids..then again I heard aggressive behavior in doodles could also be to thyroid issues so they should be checked through blood work. I have to say the minute he bit my 2yr old niece right in front of me and I saw how gentle she was petting him...my mind was made up. Anyone have any advice or opinions?? The idea of having a newborn and a dog that seems to have anxiety around children is not too appealing. Once again my husband and I love him. No dog is perfect, no owner is perfect. Thanks.