FNAIT anti-HPA-1a antibodies with decreased fucosylation are present years after delivery. The degree of anti-HPA-1a Fc fucosylation (specific IgG1 fucosylation minus total IgG1 fucosylation) is plotted against the time after delivery, for 7 anti-HPA-1a FNAIT samples (period of 6 weeks to 7 years postdelivery).