Objective:To summarize and compare the characteristics of oral microbiota in women during the preconception period and the third trimester.Methods:This retrospective cohort study involved 55 women who were recruited in the Preconceptional Offspring Trajectory Study (PLOTS) conducted by Fudan University and followed up to the third trimester in the Maternal and Child Health Care Hospital of Jiading District of Shanghai from September 2016 to December 2019. A total of 110 unstimulated saliva samples were collected in the preconception period ( n=55) and the third trimester ( n=55). Features of oral microbiota in the samples were analyzed by 16S rRNA gene-based sequencing. Moreover, the related factors were also analyzed. Paired t test or Wilcoxon matched-pairs signed-ranks test were used to analyze the differences in α-diversity during preconception and the third trimester; t test, analysis of variance (ANOVA), Kruskal-Wallis test and Mann-Whitney U test for comparison between groups with different characteristics and permutational multivariate analysis of variance (PerMANOVA) for β-diversity were used; Linear discriminant analysis (LDA) effect size (LEfSe 1.0) was used to identify the iconic oral flora. Results:(1) The Ace index of oral microbiota was significantly lower in the third trimester than that in the preconception period [661.14(578.15-752.85) vs 730.64 (632.40-911.00), T=1 077.00, P=0.010]. There was also a significance difference in β-diversity ( F=12.539, R2=0.104, P=0.001). Some species such as Saccharibacteria_TM7_G3, Prevotella_7, Absconditabacteria_SR1_G1, Porphyromonas, Ruminococcaceae_UCG_014, Prevotella, Peptostreptococcus, Prevotella_2, Alloprevotella, Parvimonas, Solobacterium and Eubacterium_nodatum_group in saliva were statistically more abundant in the third trimester than those in the preconception period (all P<0.05). (2) The third-trimester Shannon index was lower among those with lower income [5.44 (5.08-5.77) vs 5.75 (5.44-6.12), U=219.00, P=0.029] and those with gargle habit after meal or dessert [5.36 (4.91-5.48) vs 5.72 (5.44-6.05), U=374.00, P=0.046]. Conclusions:The features of oral microbiota vary in women during the preconception period and the third trimester. There is a significant increase in the abundance of oral pathogenic and opportunistic bacteria in the third trimester.

Preconception cohort studies allow us to conduct in-depth investigations on exposures and heath related factors of couples before pregnancy, and to explore the impact on reproductive health of the couples and on short- and long-term health of the offspring. As a critical window into early life, this area has been gradually gaining much attention worldwide. This paper summarized the characteristics of 21 transnational preconception cohort studies with large samples size, to provide information for relevant researchers in China. Emphasis on international cooperation, application of highly efficient data systems or research tools, and long-term longitudinal survey on parents and their offspring are the direction of further preconception cohort researches.

ObjectiveTo evaluate the validity of four screening questionnaires on chronic obstructive pulmonary disease (COPD) among community residents in Shanghai, and to provide a scientific basis for selecting suitable screening questionnaires and plans for the community use. MethodsA multi-stage random sampling method was used to select community residents aged ≥40 for COPD questionnaire screening and spirometry. The screening questionnaires included the COPD Population Screener Questionnaire (COPD-PS), the COPD Screening Questionnaire (COPD-SQ), the COPD Diagnosis Questionnaire (CDQ), and the Lung Function Questionnaire (LFQ). The diagnostic gold standard for COPD was defined as a ratio of post-bronchodilator forced expiratory volume in one second to forced vital capacity (FEV1/FVC) less than 0.7. The receiver operating characteristic (ROC) curve was used to assess the validity of each questionnaire, and DeLong’s test was used to compare the area under the curve (AUC) of different questionnaires. ResultsAmong the 1 122 residents screened, 99 (8.8%) were diagnosed with COPD based on the gold standard criteria. The AUC values for the four questionnaires ranged from 0.643 to 0.682, with no statistically significant differences in screening accuracy among them (P>0.05). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for each questionnaire at recommended cut-off points were as follows: COPD-PS (sensitivity: 33.3%, specificity: 84.9%, PPV: 17.6%, NPV: 92.9%), COPD-SQ (34.3%, 85.8%, 19.0%, 93.1%), CDQ (73.7%, 42.4%, 11.0%, 94.4%), and LFQ (48.5%, 74.8%, 15.7%, 93.8%). Optimal cut-off values for this population differed from the recommended values. When selecting the optimal cut-off value, the sensitivity of COPD-PS (58.6%), COPD-SQ (55.6%), and LFQ (64.7%) increased, while the specificity of CDQ (75.9%) increased. The AUC of sequential lung function testing for all four screening questionnaires increased to 0.7 or above. The optimal cut-off values for the four questionnaires in this population differed from the recommended values. When applying the optimal cut-off values, the sensitivity of three questionnaires increased: COPD-PS (58.6%), COPD-SQ (55.6%), and LFQ (64.7%), while the specificity of CDQ rose to 75.9%. The AUC of each questionnaire increased to above 0.7 when followed by sequential lung function testing. ConclusionThe COPD-PS, COPD-SQ, CDQ, and LFQ have limited value for COPD screening among Shanghai community residents, indicating that further refinement of these tools is needed.

The preconception cohort is of great importance to explore and analyze the impact of multiple factors before and during pregnancy on human reproductive health, pregnancy outcomes and offspring health. This paper summarizes the information and characteristics of the preconception cohort studies in recent years in China.