Table 2.

Infants with thrombocytopenia among cases and controls, by postmenstrual age (PMA) at platelet level

PMA at platelet level	Cases, n/N (%)	Controls, n/N (%)	P value
24	4/4 (100)	4/9 (44)	0.105
25	10/13 (77)	8/19 (42)	0.075
26	13/18 (72)	12/29 (41)	0.070
27	15/20 (75)	18/42 (43)	0.029a
28	14/22 (64)	20/50 (40)	0.077
29	13/26 (50)	13/53 (25)	0.040a
30	15/30 (50)	17/59 (29)	0.063
31	20/34 (59)	14/62 (23)	<0.001a
32	20/42 (48)	13/61 (21)	0.009a
33	19/39 (49)	18/67 (27)	0.034a
34	20/47 (43)	16/66 (24)	0.044a
35	13/45 (29)	14/70 (20)	0.367
36	16/48 (33)	14/70 (20)	0.132
37	13/44 (30)	18/69 (26)	0.829
38	13/35 (37)	14/58 (24)	0.239

^aP < 0.05.