The purpose of this study is to determine if inadvertent receipt of the BioThrax vaccine during pregnancy is independently associated with adverse maternal, pregnancy, or infant health outcomes.

This study will use a convenience sample and passive referral to enroll participants.

For the maternal outcome portion of the study, pregnant active duty women who consent to join the registry are expected to complete several surveys over the course of their pregnancy, including an initial enrollment survey, a follow-up survey at or after the 20th week of pregnancy, and a post-delivery survey at two weeks after their delivery due date (unless a pregnancy loss is reported in the 20 week survey).

Outcomes among infants born to women enrolled in the Registry whose pregnancies result in a livebirth will be assessed with a survey during the post-delivery contact, again at 4 months of age, with a final follow-up when the infant reaches one year of age.

Inclusion Criteria:

• Female active duty service member
• Received one or more dose of BioThrax while pregnant, with the onset of pregnancy defined as the first day of the last menstrual period.

Exclusion Criteria:

• Non-service member, non-active duty pregnant female.

Active duty female service members who received one or more doses of BioThrax® while pregnant, with the onset of pregnancy defined as the first day of the last menstrual period (LMP) All live born infants born to women who join the registry.