Objective: To understand the prevalence and epidemiological features of anemia during pregnancy in China. Methods: The literature retrieval was conducted by using China Biology Medicine disc (CBMdisc), China National Knowledge Infrastructure (CNKI), Wanfang Data, China Science and Technology Journal Database (CSTJ), PubMed, Cochrane Library and Embase database. The time was from January 2012 to October 2017, and the language was limited to Chinese and English. The Chinese and corresponding English search terms included pregnancy, anemia, epidemiology and prevalence. Results: A total of 28 papers were included. The total number of participants investigated was 58 752, with 11 588 cases with anemia during pregnancy identified. The overall prevalence of anemia during pregnancy was 19.9% (95%CI: 16.3%-23.5%). The prevalence varied in anemia with different levels. The prevalence of mild, moderate and severe anemia were 15.9% (95%CI: 11.7%-20.2%), 5.7% (95%CI: 4.5%-6.8%) and 1.3% (95%CI: 0.8%-1.8%) respectively. The prevalence of mild anemia was highest and the prevalence of severe anemia was lowest. The prevalence of anemia increased with gestational weeks. The prevalence of anemia at the first, second and third trimester of pregnancy were 10.1% (95%CI: 6.2%-14.0%), 26.7% (95%CI: 18.0%-35.5%) and 28.1% (95%CI: 21.0%-35.1%) respectively. Both degree and gestational week subgroup analysis showed a significant difference among groups (P<0.05). There were no statistically significant differences among subgroups of cut-off year, region, resident area, age, education level and parity (P>0.05). Conclusion The prevalence of anemia during pregnancy in China had remained at a low level during the past 5 years. The prevalence of mild anemia was higher than that of moderate and severe anemia. The prevalence of anemia in women at the second and third trimester of pregnancy was higher than that at the first trimester of pregnancy. Women at the second and third trimester of pregnancy should be attached a great importance in the prevention and control of anemia during pregnancy.

Objective:To observe the histopathological changes in peripheral retinal lesions under intraoperative optical coherence tomography (iOCT).Methods:A retrospective case series study. Eighty-eight patients (194 eyes) who underwent vitreoretinal surgery in the Department of Ophthalmology at the East Ward of the First Affiliated Hospital of Zhengzhou University from October 2021 to May 2022 in 94 eyes were included in the study. Among them, 49 cases were male and 39 cases were female, with the mean age of (50.93±17.55) years. Ninety-four eyes included 32 eyes with retinal detachment, 6 eyes with proliferative diabetic retinopathy, 28 eyes with vitreous hemorrhage, 8 eyes with ocular trauma, 14 eyes with the macular lesion, 1 eye with uveitis, 1 eye with family exudative vitreoretinopathy (FEVR), 1 eye with acute retinal necrosis (ARN), and 3 eyes with lens dislocation. All affected eyes were examined with iOCT during vitreoretinal surgery. The iOCT scanning of the peripheral retina was performed with the help of episcleral pressure. The pre-equatorial and serrated edge anterior and posterior of retinas were scanned according to the characteristics of different fundus diseases. Various abnormal fundus manifestations were recorded.Results:In 94 eyes, 53 eyes (56.38%, 53/94) have different types of retinopathy in the peripheral retina. Of these, 7 eyes (7.45%) have retinal cystoid degeneration; 19 eyes (20.21%) have lattice degeneration; and 8 eyes (8.51%) have pigment degeneration; 9 eyes (9.57%) have pavement-like degeneration; 7 eyes (7.45%) have small occult holes; 1 eye (1.06%) has familial exudative vitreoretinopathy (FEVR) serrated edge "dyke-like" proliferative degeneration; 4 eyes (4.26%) have vitreous and retinopathy adhesions; and one eye (1.06%) has ARN.Conclusion:With clear refractive media, iOCT can provide clear scans of different peripheral retinal lesions.