Birth cohort study has played an important role in exploring the effect of exposures in early life on long-term health of offspring. With the rapid increase of problems of reproductive health among couples at childbearing age, the assisted reproductive technology (ART) has been widely introduced into clinical practice. However, the influences of ART on long-term outcomes of mothers and infants have not been fully studied. In 2016, the China National Birth Cohort (CNBC), a multicenter prospective cohort study recruiting families with ART-conceived pregnancies and spontaneous-conceived pregnancies simultaneously was launched officially. By June 30, 2021, a total of 72 000 families covering 39 000 ART- pregnancies and 33 000 spontaneous- pregnancies have been recruited in the study, their information and biological samples were collected at multiple time points, i.e., before assisted reproductive treatment, in embryo transfer period, in first, second and third trimesters, at delivery, and at 42 days after birth, 6 months, 1 year old and 3 years old. The main objectives of this study are to assess the development and health of offspring born after ART treatment, identify risk factors associated with adverse birth outcomes and childhood diseases and provide scientific basis for the strategies to improve the quality of new birth population. This paper will give a brief introduction to the establishment and research progress of CNBC.

Humans ; Genetic Predisposition to Disease ; Multifactorial Inheritance ; Genome-Wide Association Study ; Risk Factors

Objective:To evaluate the possible mediation effect of smoking and healthy diet score on the association between educational level and the risk of lung cancer incidence.Methods:After excluding individuals with missing educational levels and cancer information at baseline, 446?772 participants in the UK Biobank (UKB) prospective cohort study were included. Cox regression models were used to investigate the associations of educational level and smoking and healthy diet score with the incidence of lung cancer. Mediating effect analysis was conducted to analyze the mediating effect of smoking and healthy diet score on the correlation between educational level and lung cancer.Results:During a median follow-up of 7.13 years, 1?994 new- onset lung cancer cases were observed. Per 1 standard deviation (5 years) increase in educational level was associated with a 12% lower risk of lung cancer ( HR=0.88, 95% CI: 0.84-0.92). The corresponding level 1-5 in the International Standard Classification for Education (ISCED) were mapped to UKB self‐report highest qualification to estimate the educational level. A higher rank means a higher educational level. Compared with level ISCED-1, the HR(95% CI) of level ISCED-2, ISCED-3, ISCED-4 and ISCED-5 were respectively 0.83 (0.72-0.94), 0.67 (0.53-0.85), 0.76 (0.65-0.89) and 0.72 (0.64-0.80) for lung cancer. Education years were negatively correlated with smoking, with β coefficients (95% CI) being -0.079 (-0.081- -0.077), but positively correlated with healthy diet score ( β=0.042, 95% CI: 0.039-0.045). Analysis of mediating effect indicated that the association of educational level with lung cancer risk was mediated by smoking and healthy diet score, the proportions of mediating effect were 38.952% (95% CI: 31.802%-51.659%) and 1.784% (95% CI: 0.405%-3.713%), respectively. Conclusion:Smoking and healthy diet score might mediate the effect of educational level on the incidence of lung cancer, indicating that improving the level of education can reduce the risk of lung cancer by changing lifestyles such as smoking and diet.

Liver cancer is one of the most common cancers in China. In recent years, liver cancer tends to be treated with comprehensive therapies, including surgery, ablation, interventional embolization, radiotherapy, chemotherapy, targeted therapy, immunotherapy, and liver transplantation. At present, the low surgical resectionrate is one of the main factors affecting the prognosis of liver cancer patients. Preoperative neoadjuvant therapy or conversion therapy for liver cancer can maximize the rate of surgical resection and improve the prognosis. With the rapid development of radiotherapy and immunotherapy in the comprehensive treatment of liver cancer, it has been gradually confirmed that the unique effects of preoperative radiotherapy and immune therapy for liver cancer can improve the prognosis of the patients. Therefore, this paper reviewed the research progress in the preoperative radiotherapy and immunotherapy for liver cancer by searching relevant literature and reports at home and abroad.

Recent years with the rapid progress in high-throughput omics techniques, the accumulation of population cohorts and biobanks, great advances in internet and information technology, and the emerging tools for big data utilization, health care big data provide abundant data resources and broad research platforms for epidemiological research. We aimed to review the opportunities and challenges of epidemiological research in the era of big data, and explore the future development of epidemiology. Epidemiology should seize the opportunities, open up new directions, develop new methods, and promote the translation of research results into public health and clinical medicine, which will eventually realize the vision of "Healthy China".

Objective:To explore how to personalize lung cancer screening programs for prevention in Chinese populations based on individual genetic risk score.Methods:We constructed the lung cancer polygenic genetic risk score (PRS-19) based on the 19 previously published genetic variations, using 100 615 participants with genotyping data from the China Kadoorie Biobank (CKB). Using the 5-year absolute risk of lung cancer in a population (55 years old with at least 30-pack-year history of smoking) as reference, the trend of 5-year absolute risk in different genetic risk groups was calculated in smokers and non-smokers, respectively. Distribution curves of 5-year absolute risk were also described to determine the theoretical age or smoking dose when different genetic risk groups reached the reference values. Given the overall findings, the specific start age for lung cancer screening were suggested for different genetic risk groups.Results:The 5-year absolute risk of lung cancer was 0.67% in 55-year-old smokers with 30 packs per year in the CKB. Among smokers, 5-year absolute risk of participants increased as the genetic risk increased. Hence, it was recommended that people at high genetic risk should start screening earlier. For the highest genetic risk populations (the top 1% of PRS), the start age might be changed to 50 years old. If the start age remained at 55-year-old, the smoking dose should be set lowered in high genetic risk populations. For the highest genetic risk populations, they should be included in lung cancer screening regardless of the cumulative smoking exposure. Among nonsmokers, it was also valuable to screen people with high genetic risk, considering the start age of 62 for the highest genetic risk populations and 74 for the lowest genetic risk populations (the bottom 5% of PRS).Conclusions:PRS-19 can be effectively used in developing lung cancer screening program for individualized prevention in China. For smokers with high genetic risk, the recommended starting age and smoking dose could be lowered for lung cancer screening, and non-smokers with high genetic risk could also be included in the screening programs.

With the rapid changes in lifestyle, natural and social environment, the reproductive health status of couples in childbearing age continues to decline, and long-term outcomes of the rapidly increasing offspring conceived by assisted reproductive technology (ART) needs to be evaluated urgently. Therefore, the focus of research now needs to be extended from death and severe diseases to full life cycle and full disease spectrum. In order to meet the demand for such research, we launched the China National Birth Cohort (CNBC) study, an ongoing prospective and longitudinal study aiming to recruit 30 000 families underwent ART and 30 000 families with spontaneous pregnancies. Long-term follow-up programs will be conducted for both spouses and their offspring. Data of couples and their offspring, such as environmental exposure, reproductive history, psychological and behavioral status, will be collected during follow-up. Peripheral blood, urine, umbilical blood, follicular fluid, semen were also collected at different follow-up nodes. Based on high-quality data and biological samples, CNBC will play an extremely important supporting role and have a far-reaching impact on maternal and children's health care and reproductive health in China. This paper is exactly a brief introduction to the construction and basic design of CNBC.

Birth cohort is an effective method to explore the relationship between various prepregnant and pregnant exposures and the health of fetuses, infants and young children. It is a long construction period to build a birth cohort and the quality of research may be affected by many factors. This paper reviews the quality assurance and quality control measures in the process of China National Birth Cohort (CNBC), and summarizes the construction experience. We aim to provide experience for related cohort studies, which could improve the quality of cohort studies through removing the impact of related factors. CNBC adopted a series of measures to ensure the quality of research in the top-level design of quality assurance, including screening research center, developing member management system, formulating standard operating procedures and training staff by it. In terms of quality control, it includes real-time, timely and timing quality control for the process of data generation, full-cycle quality control for biological sample collection, processing, storage and comprehensive three-dimensional quality control for staff training, supervision and quantitative assessment.

Objective:To explore the effects of environmental, genetic factors as well as the interactions in early life on the short-term and long-term health of offspring and to systematically evaluate the pregnancy outcomes and health of offspring after birth between families with assisted reproductive technology (ART) conception and families with spontaneous conception.Methods:The China National Birth Cohort (CNBC), a multicenter prospective birth cohort study, includes both families with ART conception and families with spontaneous conception. Since 2016, CNBC has recruited families from 24 hospitals located in 12 provinces, municipalities and autonomous regions throughout China. Information and biospecimens were collected before ART treatment, embryo transfer, at early, second, third trimester and delivery, and at 42 days, 6, 12 and 36 months after birth.Results:By June 2020, CNBC had included 27 044 families with ART conception and 29 589 families with spontaneous conception. The majority of the participants are urban residents. Among the families with ART conception, 65.5% of the men and 63.7% of the women had college degrees or higher. The mean age distribution of men and women was (33.83±5.52) and (32.38±4.67) years. 83.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.8% and 2.1% in women. Among the families with spontaneous conception, 81.5% of the men and 86.5% of the women had college degrees or higher. The mean age distribution of men and women was (32.06±5.09) and (30.40±4.27) years. 67.2% of women were primiparas, and the prevalence rates of current regular smokers and current alcohol drinkers were 0.1% and 2.2% in women. The baseline characteristics were different between the families with ART conception and spontaneous conception in different regions.Conclusion:CNBC provides a powerful and rich resource in studying the impact of genetic, environmental factors and interactions in early life and ART treatment on the health of offspring after birth.