Re: No sex during or after pregnancy (18 months total)
Joe, with an 18 month dry spell you are way beyond date nights and letting her have some free time.
You have to have a conversation where she either acknowledges that a marriage is a sexual relationship or doesn't. If she feels that marriages do not need to be sexual, then you two are on a very different page in terms of core values.
IF she acknowledges that marriage is sexual, ask her what steps she needs to take to turn her marriage into a properly functioning marriage.