Background: To appraise the impact of the changing national childbirth policy since 2002, currently allowing two children per family, on obstetric workload in a regional referral center in China. Methods: In a retrospective cohort study, temporal changes in maternal demographics, incidence of high-risk pregnancies, and resource statistics in our hospital in managing singleton viable pregnancies (birth at ≥28 weeks gestation) for the period 2005-2017 were examined. Findings During this 13-year period, there were 49,479 singletons live-born infants delivered at ≥28 weeks gestation, the annual delivery increasing from 1,941 in 2005 to 5,777 in 2017(p<0.001). There were concomitant and significant (p<0.001) increases in the incidence of parturients of multiparity status (10.6% to 50.8%), of age ≥35 years (6.5% to 24.3%), with prior CS (2.6% to 23.6%), and with ≥3 previous pregnancy terminations (1.0% to 4.9%). There were associated increases in beds and staff complement, and reduced average hospital stay. Nevertheless, while medical staff maintained a stable service efficacy, that for nursing and midwifery staff increased 1.7 fold from 194.1% to 320.9% (p<0.001). Interpretation In our hospital, there has been progressively increasing total annual births and especially incidence of high risk pregnancies following the revised national childbirth policy. Only the increase in medical but not nursing/midwifery staff was commensurate with workload. Our experience is likely a reflection of other tertiary centres in China as well. Remedial measures are urgently required before the anticipated progressive increase in service demand would overwhelm the obstetric service with potentially disastrous consequences. Funding Statement: The research grants of the Key Science and Technology projects (2018ZF009, 2015FA003) from the Department of Yunnan Science and Technology, the National Natural Science Founding of China (grant number 81760274), and a Ph.D. Research and Development of Kunming Medical University (2015BS018). Declaration of Interests: The authors stated: None declared. Ethics Approval Statement: The study was approved by the Health Administrative Departments of Yunnan Province, and the Medical Ethics Committee of the 1st Affiliated Hospital of Kunming Medical University.