Hello, Welcome to HCM, I am Dr. Das
you do not need too much sperm count
. Along with sperm count, most important is sperm motility
and sperm morphology. According to WHO 1999, requirement of sperm count is >20 millions / ml, requirement of sperm motility is >50%, and minimum 60% sperms should be of normal morphology.
To fertilize a ovum, a sperm has to go up to the fallopian tube
. If motility is lower than required, then the sperms are unable to fertilize a ovum in spite of having normal sperm count.
So, for pregnancy you need 50% sperm motility and 60% normal sperm.
From the above discussion it is clear that no definite comment can be done regarding pregnancy on the basis of only 31 million sperm.