Medical expenditure of women during pregnancy, childbirth and puerperium at the beginning of China's universal two-child policy enactment: a population-based retrospective study.

The rise in CCE on pregnancy, delivery and puerperium lagged 1 year behind the surge of newborns at the beginning of China's universal two-child policy. Length of stay acted as a crucial mediator driving up maternal medical expenditure. Reducing medical expenditure by shortening the length of stay could be a feasible way to effectively address the issue of cost in women during pregnancy, childbirth and puerperium.