It is a very difficult situation for a family, and presents ongoing problems in raising the child because of parental mindsets and assumptions.
Thankfully, chromosome testing does help in determining the choice.
But, like Salty said, it is very rare.
Too often when it comes to the physical roles and expectations, there are not enough educated folks in the ministry who can approach parents with adequate support.
Unfortunately, the over aggressive perverts get so much attention, that helps are (imo) pushed off to being one of that group, rather than understanding that God's child is molded with very special and particular plan and purpose from even conception.