The e-mail reads, in part:
We have received a number of calls regarding how to enter security information for a baby that has not yet been born.
Crazy as it may sound, you MUST include the baby in the overall count of guests in the tour. It's an easy process.
LAST NAME: The family's last name
FIRST NAME: "Baby" as a first name
MIDDLE NAME: NMN as in No Middle Name
DOB: Use the date you are submitting the request to us as their birthday
GENDER: if the parents know put that gender down if not, you can enter either M or F as we'll ask you to update it at the time of birth.