• The positive incidence of the anti-HPA antibody in pregnant Chinese women.
• The morbidity of NAIT in anti-HPA antibody-positive pregnant women in China.
• Antigenic specificity of anti-HPA antibodies.
• Association of the anti-HPA antibody with HLA genotype.
• The relationship between the titre of the anti-HPA antibody and the clinical symptom severity of NAIT.
• Pregnant women 18–50 years of age
• Pregnant women at 12-28 weeks of gestation between 1 January 2017 and 31 December 2018.
• Willingness of the mother to give birth in a participating hospital
• Willingness to participate in the study
• Pregnant women unwilling to participate in the study
• Pregnant women planning to prematurely terminate the pregnancy