Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Derivation of the final subset of Collaborative Perinatal Project study participants used in the analysis of the association between body mass index and time to pregnancy. Pregnant women enrolled in the Collaborative Perinatal Project at 12 study centers in the United States from 1959 to 1965.
