The period encompassing the weeks before a birth, the birth, and the few weeks thereafter is called:
a. perinatal.
b. childbirth.
c. neonatal.
d. postpartum.

This is called the Perinatal period - with "peri" meaning around.

The other options are:

b. childbirth.
-this refers to the process of giving birth itself,

c. neonatal.
This word refers to just after birth, and it is used in the development of children, so it is rather used for the children than for mothers.

d. postpartum.
-this means after birth