Can i still get.pregnant with.40% kid.ey function?

You probably: Can but consult with your nephrologist. A better question would be whether the kidneys can sustain pregnancy. The blood volume increases by 50%. The other question is why the poor renal function? The underlying process that caused poor renal function may cause problems with the pregnancy and you could have additional problems like increased risk of pressure issues. It will not be an easy ride.