Table 1. Clinical characteristics of maternal serum samples in HUVEC experiments.

	Obstetric history		Index pregnancy
case*	ICH in previous pregnancyaa –/+b	Platelet count previous childc (< or >50 × 109/l) –/+b	Titre of HPA-1a-Absd pre-IVIGf (1)e	Titre of HPA-1a-Absd post-IVIGf (1)e	HLA-Absd +/–/±b	Platelet count in index pregnancyc (< or >50 × 109/l) –/+b
1	+	–	64	40	–	–
2	–	–	80	128	+	–
3	–	–	10	32	+	+
4	+	–	40	64	–	–
5	+	–	10	8	+	+
6	– (†)	–	40	32	±	–
7	–	–	4	32	±	–
8	–	–	32	16	–	–
9	–	–	4	4	–	–
10	–	–	128	32	–	–
11	–	–	32	32	–	+
12	–	–	40	16	–	+
13	–	–	10	4	–	+
14	–	–	32	16	–	+
15	–	+	32	16	–	+
16	+(†)	–	32	32	–	+
17	–	–	40	16	±	+
18	–	–	4	4	±	+
19	–	–	64	8	–	+

^*Serum sample of mothers that have been treated intravenously with immunoglobulin G (IVIG) during the pregnancy of a child at risk of alloimmune thrombocytopenia;

^aoccurrence of intracranial haemorrhage (ICH) in a previous pregnancy due to severe alloimmune thrombocytopenia; Abs = antibodies;

^b+ = yes or presence, –= no or absence, ± = weak presence;

^cplatelet count at birth, <50 = –, >50 = +;

^danti-HPA-1a- or HLA class I-antibodies;

^etitre of antibodies, for example 1 in 32;

^fpre-IVIG = serum sample taken before start of IVIG treatment, post-IVIG = serum sample taken after IVIG-treatment;

^†= deceased.