[Objective]To ascertain characteristics of sexual partner network and high-risk sex behaviors among men who have sex with men (MSM) , providing references for intervention of high risk behavior in MSM. [Methods] Face-to-face questionnaire interview was conducted among MSM recruited by voluntary counseling and testing clinics, peer mobilization, internet mobilization, outreach intervention, and so on.Descriptive statistics, χ2test, logistic regression analysis were applied for statistical analysis. [Results]A total of 334 MSM was investigated. Over the past 6 months, proportion of female partners, fixed male partners, multiple male partners, occasional and business male partners was 37.13％, 43.11％, 52.69％, 56.29％, and 4.19％ respectively. Logistic regression analysis showed that respondents who were married, less educated, non-Shanghai domicile, and non-homosexual had more female partners in proportion, those with high income and homosexuality had more fixed male partners in proportion, and those who were married, non-Shanghai domicile had more multiple or occasional male partners in proportion. In the past 6 months, MSM who had unprotected sexual behaviors with female partners, fixed male partners, multiple or occasional male partners accounted for 75.21％, 65.97％, 59.66％, and 48.40％respectively. And analysis showed that respondents had more high-risk sexual behaviors with multiple male partners with their age increasing. [Conclusion] Sexual partner network of MSM is complex. MSM has a variety of sexual partners. Multiple sexual partners and unprotected sexual behaviors exist extensively among MSM. Related factor of sexual behaviors with multiple sexual partners is age.

Objective To investigate the levels of serum Vitamin D(VD) from preconception to pregnancy in Jiading district of Shanghai, and explore the risk factors of VD concentration deficiency in the second and third trimester of pregnancy. Methods A total of 94 women who planned to have antenatal care and delivery in Maternal and Child Health Hospital of Jiading district of Shanghai from September 2016 to December 2018 were recruited as the study participants. Chemiluminescent immunoassay (CLIA) was used to examine the concentration of women’s serum VD from preconception to pregnancy. A total of 282 serum samples were detected. Results The prevalence of VD deficiency among 94 women from preconception to pregnancy were 40.4%,57.4% and 48.9% respectively. Results of the mixed linear model showed that women who had dyed or permed hair within the past 1 year had significantly lower serum VD levels during pregnancy (P<0.05), and women who often drank milk and ate deep-sea fish during pregnancy had higher VD levels during pregnancy (P<0.05). Conclusions VD deficiency was common among women in Jiading district of Shanghai, and it should be emphasized to supplement VD before and during pregnancy.