Fig. 1.
Flow-chart study population. 1,2,3Total female birth cohort alive the 1st of January the year of sample collection [29].
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.