You can do this, but keep in mind that the baby may come early or that there maybe complications before the due date. Also, once you wife quits where would she be signing up for insurance? There may be some issues here since technically she could be on your insurance at this time.
I might propose that you have a low deductible plan from Jan 1 until after the baby is born. Once that life event occurs, you then can change to a high deductible plan if both mother and child are healthy. This is the approach that I took, but our child was due much earlier in the year.