Patient Sample Collection

Collection of human endometrium, decidua, and serum was carried out with the approvals of the Medical Ethics Committee of Nanfang Hospital, Southern Medical University, the Scientific Research Ethics Committee of the Drum Tower Hospital, Nanjing University Medical School, and the Ethical Committee of the Women’s Hospital, Zhejiang University School of Medicine. Serums (n = 15) and endometrial biopsies (n = 9) of the non-pregnant group were collected during a regular medical examination. Serums of the pregnant patients (n = 13) were collected during the first visit of antenatal care at 5.93 ± 0.71 weeks of gestation. 6 of them were sampled the 2nd time at about 2 weeks after elective abortion. Decidual tissues (n = 9) were collected from women undergoing an elective abortion in the first trimester of pregnancy. There are no significant differences in gravidity, parity, and BMI between the two groups. Serum levels of UA were measured by Blood Uric Acid Analyzer (Roche Applied Science, Basel, Switzerland). Tissues were fixed in 4% PFA and embedded in paraffin for further use. All the patients were written noticed before sampling. Demographic information on the patients who provided samples for this study is included in Table 1.

Patients information.