H4 to h1 status then back to h4 and back to h1 status

I am on h4 visa now, through an employer i got my h1 visa which is currently in RFE so i would start from jan 2018 probably. My concern is that I am carrying and will deliver in June 2018, so can I change from H1 to h4 back again without even starting my job with the new employer? So that I can take care of my kid and then start my hob properly.

Please guide me.