In 5 years of forum watching, your case is one of 2 or 3 legitimate situations where your wife truly cannot travel by commercial air. I am cynical because women at 24 weeks will claim they cannot travel simply because they want a USC child - bunk!
First ,since you are an employee transfer to the US, what are your employer's obligations for your and your family's return home? Will you still be working for him then? What is he proposing given your situation? Is he obligated to pay for your return trip? Your dependents?
What med-evac insurance do you have? Travel by your wife would require a specialized plane and aircrew - including nurse, paramedic or other medical professional. This may be part of your employment contract or corporate policy. The cost of this would depend on the distance and circumstances. I can tell you I paid about $11,000 5 years ago to have my parent transported 1/2 way across the US. Most likely any transport to Asia or Europe would exceed $100,000. If your employer is responsible, this could stall your termination date until after your wife delivers and the baby has papers to travel by commercial air. The best case if you are to be terminated/reassigned that the cost of proper travel would have your relocation date set for 3-4 months from the original date.
You could apply for B2 visas; even if denied, the processing time will allow you to remain. Leave ASAP. If before you leave before you receive a decision, everything is OK.
Speak with an attorney about the consequences of doing nothing and becoming out of status. You will have consequences of the out of status and possible illegal presence later. It would not be a concern if you do not intend to return to the US in the future. Do this only after you speak with an attorney as this is not the legal thing to do. I would suggest options 1 or 2 as certainly possible options to allow you to remain in the US legally for several months.
Take all of your employment contracts, employee handbook, insurance information, and approvals with you to an immigration attorney who can assist you in developing a plan.
