Fig. 3From: Incidence and risk factors of infertility among couples who desire a first and second child in Shanghai, China: a facility-based prospective cohort studyInfertility rates in different years (2013: 15.2%; 2014: 16.8%; 2015: 19.1%; 2016: 21.4%; 2017: 21.3%) (Trend P test < 0.01)Back to article page