Figure legends
Figure 1. Flow
charts of data according to eligibility for inclusion in the analysis
(A) and process of collecting TTP from different participants (B).
Figure 2.Estimated survival
function curve for TTP, corresponding to the elapsed time from stopping
contraception to confirmation of pregnancy or end of pregnancy attempt
in the overall population (A) and in Group 1 (C), and sorted by age of
women (B) in the overall population and in Group 1 (D). Group 1
comprises women who had spontaneous pregnancy in the last year. Solid
lines represent the curves for the estimated TTP censored at 120 months;
dashed lines represent the 95% CIs around those curves.
Figure S1. Flow
chart of multistage stratified cluster sampling strategy during
participant selection.
In primary sampling units, the
districts were categorized into two strata, representing high and low
prevalence of infertility according to the prevalence in each district
reported in 1988. Subsequently, two provinces/municipalities were
randomly selected from each stratum. In secondary sampling units,
townships in every province/municipality were ranked according to the
local per capita gross domestic product and the number of women
of childbearing age and were divided into nine strata. Subsequently,
three townships were randomly selected from the highest, moderate, and
lowest strata, respectively. In third sampling units, participants aged
20–49 years were identified in the selected townships; among these
townships, every village/street was investigated as a unit.