Table 1. Maternal Serology and Cord... | American Society of Hematology

Table 1.

Maternal Serology and Cord Blood Platelet Counts in 46 HPA-1a Alloimmunized Women

Unique Study Number	Parity^-150	Earliest Antibody Positive Sample	Anti–HPA-1a Titer in Third Trimester	HPA-1 Genotype/ Phenotype of Father	Platelet Count at Birth (×10⁹/L)
Persistent Antenatal Antibodies With Severe Thrombocytopenia (n = 10)
274	4 + 0	7	32	1a1b	37
57	0 + 1	8	128	1a1b	6
622	1 + 0	10	64	ND	9
306^-151	2 + 1	16	128	ND	17
479	2 + 0	17	64	1a1a	8
152^-152	0 + 1	16	64		ND
	0 + 2	21	16	1a1b	5
347^-153	0 + 0	26	64	1a1a	4
421	0 + 0	32	8	1a1a	2
LR^-155	0 + 0	ND	ND	1a1a	14
SL^-155	0 + 0	ND	ND	1a1a	ND
Persistent Antenatal Antibodies With Mild Thrombocytopenia (n = 10)
223	3 + 0	9	16	1a1b	110
598	0 + 1	12	8	ND	60
639	1 + 0	12	2	1a1b	107
60	1 + 4	14	1	1a1a	117
424	1 + 0	17	1	1a1a	52
620	0 + 0	17	2	1a1a	132
64	1 + 0	19	4	1a1a	94
330	2 + 0	21	32	1a1a	97
54	0 + 0	26	1	ND	118
178	0 + 0	30	1	ND	140
Persistent Antenatal Antibodies With Normal Platelet Counts (n = 7)
599	1 + 2	11	1	1a1a	335
248	1 + 0	16	1	1a pos	215
322	1 + 0	16	32	1a1a	197
571	0 + 0	17	8	1a1a	323
481	2 + 1	18	16	1a1b	192
431	0 + 0	37	2	1a1b	491
607	0 + 0	37	4	ND	228
Transient Antenatal Antibodies (n = 6)
487	3 + 1	8	2	1a1b	ND
614	1 + 0	8	2	1a1b	267
605	1 + 0	9	1	ND	133
398	3 + 0	15	1	ND	261
206	2 + 1	16	1	ND	604
420	0 + 1	20	1	ND	352
Postnatal Antibodies Only With HPA-1a–Positive Baby¶ (n = 7)
42^-151	0 + 0	PN	1	1a1a	ND
62	2 + 1	PN	8	ND	275
221	0 + 1	PN	2	1a1a	153
267	1 + 0	PN	4	1a1b	274
302	1 + 3	PN	4	1a1a	SA 15/40
325	0 + 0	PN	1	ND	146
412	1 + 2	PN	4	1a1a	53
Antenatal Antibodies With HPA-1a–Negative Baby (n = 6)
417	1 + 1	11	32	1a1b	286
199#	0 + 1	17	4	1a1b	222
230^-160	1 + 2	17	16	1b1b	229
304	4 + 0	26	2	1a1b	384
172	2 + 0	29	1	1a1b	341
542	0 + 1	35	2	ND	285

Unique Study Number	Parity^-150	Earliest Antibody Positive Sample	Anti–HPA-1a Titer in Third Trimester	HPA-1 Genotype/ Phenotype of Father	Platelet Count at Birth (×10⁹/L)
Persistent Antenatal Antibodies With Severe Thrombocytopenia (n = 10)
274	4 + 0	7	32	1a1b	37
57	0 + 1	8	128	1a1b	6
622	1 + 0	10	64	ND	9
306^-151	2 + 1	16	128	ND	17
479	2 + 0	17	64	1a1a	8
152^-152	0 + 1	16	64		ND
	0 + 2	21	16	1a1b	5
347^-153	0 + 0	26	64	1a1a	4
421	0 + 0	32	8	1a1a	2
LR^-155	0 + 0	ND	ND	1a1a	14
SL^-155	0 + 0	ND	ND	1a1a	ND
Persistent Antenatal Antibodies With Mild Thrombocytopenia (n = 10)
223	3 + 0	9	16	1a1b	110
598	0 + 1	12	8	ND	60
639	1 + 0	12	2	1a1b	107
60	1 + 4	14	1	1a1a	117
424	1 + 0	17	1	1a1a	52
620	0 + 0	17	2	1a1a	132
64	1 + 0	19	4	1a1a	94
330	2 + 0	21	32	1a1a	97
54	0 + 0	26	1	ND	118
178	0 + 0	30	1	ND	140
Persistent Antenatal Antibodies With Normal Platelet Counts (n = 7)
599	1 + 2	11	1	1a1a	335
248	1 + 0	16	1	1a pos	215
322	1 + 0	16	32	1a1a	197
571	0 + 0	17	8	1a1a	323
481	2 + 1	18	16	1a1b	192
431	0 + 0	37	2	1a1b	491
607	0 + 0	37	4	ND	228
Transient Antenatal Antibodies (n = 6)
487	3 + 1	8	2	1a1b	ND
614	1 + 0	8	2	1a1b	267
605	1 + 0	9	1	ND	133
398	3 + 0	15	1	ND	261
206	2 + 1	16	1	ND	604
420	0 + 1	20	1	ND	352
Postnatal Antibodies Only With HPA-1a–Positive Baby¶ (n = 7)
42^-151	0 + 0	PN	1	1a1a	ND
62	2 + 1	PN	8	ND	275
221	0 + 1	PN	2	1a1a	153
267	1 + 0	PN	4	1a1b	274
302	1 + 3	PN	4	1a1a	SA 15/40
325	0 + 0	PN	1	ND	146
412	1 + 2	PN	4	1a1a	53
Antenatal Antibodies With HPA-1a–Negative Baby (n = 6)
417	1 + 1	11	32	1a1b	286
199#	0 + 1	17	4	1a1b	222
230^-160	1 + 2	17	16	1b1b	229
304	4 + 0	26	2	1a1b	384
172	2 + 0	29	1	1a1b	341
542	0 + 1	35	2	ND	285

Within each category, cases are listed according to timing of first detectable antibody.

Abbreviations: ND, not determined; SA, spontaneous abortion; PN, postnatal.

Parity: number of births after 24 weeks + number before 24 weeks.

Also produced anti–HPA-5b antenatally.

Two pregnancies during the study period.

Intracerebral hemorrhage in utero.

Not originally typed as HPA-1a negative.

¶Titre refers to postnatal sample.

#HLA-DRB3 *0101 negative.

New partner: previous child HPA-1a positive with severe thrombocytopenia.