Email to HR requesting to end onsite assignment

Please help me to correct my mail below. I want to write as formal as possible so my HR so they accept my request.

Dear Madam,

In regards to my recent email trail below, your assistance here in is greatly appreciated.

Kindly grant my request to end my onsite assignment. Reason being my wife is Pregnant and she wanted to conceive baby in home country. She wants me to be with her on her gestation period.

Currently she fells sickness, anxiety this time and she is insisting me to go back to home country and starts medical treatment there as soon as possible. We do not want to take any change on her first pregnancy.

I hope you understand my concerns.

Regards,
XYS