Sociodemographic and economic characteristics of susceptibility to rubella among women preparing for pregnancy in rural China

Objectives: Infection with rubella virus during pregnancy can result in congenital defects and adverse pregnancy outcomes. The risk of rubella infection is greatly determined by the level of rubella antibodies in the serum. A survey of rubella antibody seronegativity rates was conducted in 780 000 women in rural China who were planning a pregnancy, in order to evaluate the herd susceptibility in different age groups and by high, middle, and low GDP per capita regions. Methods: In order to evaluate the herd susceptibility to rubella, a nationwide population-based study of rural Chinese women who were planning to have a baby and who were aged 21–49 years was instigated. As a part of the National Free Pre-conception Health Examination Project covering 29 provinces in 2012, a physical check-up program was provided to women who planned to become pregnant within the next 6 months. All medical data were from serological samples tested by ELISA, and the participants’ immunity status was categorized based on levels of rubella antibodies. Economic data were also collected to explore the association between herd susceptibility and socioeconomic characteristics in the women of childbearing age. Results: A total 264 306 of 782 293 recruited women preparing for pregnancy tested susceptible to rubella (33.79%). The seronegativity rate in women with a history of vaccination was significantly lower than that in women who had not received the vaccination or did not know their vaccination history (23.76%, 33.70%, and 35.68%, respectively). The seronegativity rates were 26.89%, 37.86%, and 32.61% in high, middle, and low GDP per capita areas, respectively. After stratified analysis and adjusting for other factors by multiple logistic regression, the lower seronegativity rates in women in high GDP per capita regions compared to women in middle and low GDP per capita regions remained in the different age groups and subgroups of immunization history. Conclusions: There is a clear difference in rubella-specific susceptibility among rural women preparing for pregnancy of different sociodemographic and economic backgrounds. The number of rubella-susceptible rural women preparing for pregnancy, especially in relatively low GDP per capita regions in China, was high. Offering rubella vaccination to women who are rubella-susceptible and who plan to become pregnant should become one of the priorities in the field of public health work in China.