Returning to USA with Previous employer's H4 stamping with short expiry period

[Muthulakshmanan]

Hi,

I am a H4 Dependent VISA holder.I traveled to India due to my health condition and family situation for a short trip.
I have to return USA because my wife and kid are in USA. below is my VISA situations. Please guide me how to handle.

1. We came to on USA 12 Jan 2017, VISA was provided till 31 JUL 2019 and My I94 is ending on 10 August 2019.
2. Due job change, H1B visa end date and my H4 depend VISA end date ending date are moved to 31 DEC 2018.
3. New company applied for both H1B and H4 visa extension on SEP 2018.
4. My Passport is with previous employer's H4 VISA.

Now i have to return to USA and planning to return on 20 DEC 2018.

1. Is it previous employer's H4 visa stamping is enough ? because my H4 VISA is not expired ?
2. what documents are needed at POE if previous employer's stamping itself is enough?
3. Do i need a new H4 visa stamping in India ?
4. if yes, then H1B holder presence is necessary ?
5. What documents are needed ?
Please guide me