A child can not be claimed as a dependent until the year in which it is born alive.
Pre-natal care is a valid medical expense itemized deduction, but it is unlikely to provide a tax benefit. Only the amount of medical expense itemized deductions that are more than 10% of your adjusted gross income (under 65) or 7.5% (65 or over) are deducted. Also, itemized deductions provide no tax benefit until all of them added together are more than the standard deduction for your filing status.
2016 Standard Deduction
Taxpayer under 65, not claimed as a dependent
$6,300 for Single
$12,600 for Married Filing Jointly, or Qualifying Widow(er) with dependent child
$9,300 for Head of Household
$6,300 for Married Filing Separately
For over 65 or blind, add $1,250 for each instance or add
$1,550 each instance if single and not a surviving spouse.