Bo-Se 2-4 weeks before kidding. Worm the day they kid. (Some goats are sensitive to wormers and will abort. Some goats are fine with them. I don't take chances.) I also like to copper bolus a month before kidding, a B-Complex, and do a CMPK injectable. ( They are using up a lot of calcium making baby bones in that last month. )
My experience has been that everything I give the Mom-goat in the last month of pregnancy is something I do NOT have to give a newborn kid. So, I pick a day in the last month of pregnancy, and it is "maintenance day". They also get their feet trimmed, and get their kidding shave at the same time.
Since I have been doing the "Make sure Mom is up on her vitamins and minerals the last month of pregnancy":
I have not had a kid born that could not stand due to White Muscle Disease.
I have not had a kid develop Floppy Kid Syndrome.
I have not had a doe die after kidding.
I have not had a case of mastitis in a newly freshened udder. (And only ONE case of late lactation sub-clinical.)
I have, ~raps her forehead~ knock on wood, had ONLY environmental kidding problems. (See thread of doe giving birth in a flooded barn while standing tippy toe on top of a block)
Those are my pre-kidding management practices. Your mileage may vary.