In terms of inequality, the difference between urban and rural areas increased by 40% between 2000 and 2013. From the results, we noted that the inequality in IBD reached its peak after a compulsory premarital check was cancelled in 2003. Therefore, the decline in premarital medical examinations may also be a cause of the increased inequality in IBD. A premarital medical check-up plays an important role and is the primary threshold for the prevention and control of birth defects in China ; specifically, there is a greater preventive impact of premarital medical check-ups in rural, remote, and socio-economically underdeveloped areas . Additionally, the recognition and support of local governments for premarital medical examinations are more significant for the reduction in IBD and enhancement of IBD equality . Attention should be paid to the function of primary preventive methods to control birth defects, including premarital examinations, while continuously implementing functions such as the “pre-pregnancy eugenic health check” and “neonatal screening in poor areas”. Depending on the condition, regions can also expand the services of these projects based on their own needs and provide partially paid services to maximize their effectiveness.