Not any time soon. There are too many changes in the body in zero g. Increased resting heart rate, blood flow to upper part of the body (this happens right away as soon as you go into zero g), immune system not working quite right, other internal organs also not working right, loss of appetite, magnesium loss, etc etc.
It's not too bad for the astronauts since they are in zero g - is much easier to do things - everything is weightless including your body. So it doesn't matter so much that they aren't in top physical form in space. But for a mother with child, these are major issues.
Our bodies just never evolved to survive in zero g.
It wouldn't be ethical to permit it at our current state of knowledge of the situation.
Indeed women who are pregnant are not permitted to fly to the ISS.
The problem is zero g. If we had artificial gravity in space at full g it might well be possible.
For more about the medical issues see some of the answers to: