Contraception, unintended pregnancy, and induced abortion within 24 months of delivery in China: a retrospective cohort study.

Objective: To explore the prevalence of contraceptive use, unintended pregnancy, and induced abortions within 24 months postpartum in eastern, central, and western regions of China and in China overall.

Study Design: We conducted a retrospective cohort study and selected women who delivered a live birth between 12 and 24 months before the survey at 60 hospitals in eastern, central, and western regions of China. We used structured questionnaires for data collection and applied life-table analyses to estimate the prevalence of contraception, unintended pregnancy, and abortions.

Dandelion flower-like micelles.

Dandelion flower-like micelles (DFMs) were prepared by self-assembly of polycaprolactone (PCL) functionalized surface cross-linked micelles (SCMs). Upon reductive stimuli, the SCMs can be released from the DFMs by non-Brownian motion at an average speed of 19.09 μm s.