Figure 1.
Sampling flow chart of pregnant women (<20 weeks of pregnancy) and mothers in the postpartum period (2–6 months).
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.