If your spouse is staying home to take care of the kids, or at home for any reason..they still can set up and fund either the Traditional or Roth IRA each year.  Even though it's a separate IRA account, most of the major mutual fund companies or brokerages will be able to have a husband's and wife's account information on one statement. 

Also, most allow one spouse to have trading authority on their partners account.  Contact your IRA custodian.

CNNMoney.com explains spousal IRA basics.