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.
Forest plots showing the results of meta‐analysis as follows. (A) proportion of live births in subsequent pregnancy in cohort studies, (B) proportion of miscarriages in subsequent pregnancy in cohort studies, (C) proportion of preterm births in subsequent pregnancy in cohort studies and (D) odds of preterm birth in subsequent pregnancy in case control studies.
