Yes, generally speaking, it is financially beneficial as there will be a Child Tax Credit available (and possibly other credits related to having children such as EIC or Dependent Care). However, you won't be able to claim the child until he/she is born in 2018. So, you will claim the child on your 2018 tax return that you will file next year.
Here is some information about the Child Tax Credit as of now. For 2018, you won't have the benefit of being able to claim a personal exemption for your children anymore, but the Child Tax Credit will actually be increasing (by double) next year due to tax reform, so see 2017 Tax Reform - What you should know
