Table 4.

Developmental delay risk stratification in children with and without prenatal ZIKV exposure

	ZIKV exposed (n=68), n (%)	ZIKV unexposed (n=63), n (%)	χ2	Fisher’s exact p value
Cognition
Low risk of delay*	64 (94)	61 (97)	0.549	0.682
Med to high risk of delay*	4 (6)	2 (3)
Fine motor			NA*	NA*
Low risk of delay*	68 (100)	63 (100)
Med to high risk of delay*	0 (0)	0 (0)
Gross motor			NA*	NA*
Low risk of delay*	68 (100)	63 (100)
Med to high risk of delay*	0 (0)	0 (0)
Language			0.003	1.000
Low risk of delay*	67 (99)	62 (98)
Med to high risk of delay*	1 (1)	1 (2)
Positive behaviour			1.621	0.232
Low risk of delay*	55 (81)	56 (89)
Med to high risk of delay*	13 (19)	7 (11)
Negative behaviour
Low risk of delay*	56 (89)	52 (91)	0.182	0.766
Med to high risk of delay*	7 (11)	5 (9)
	ZIKV exposed (n=29)	ZIKV unexposed (n=38)	χ2	P value
Visual acuity (logMAR)			4.424	0.035
Low risk of delay†	20 (69)	34 (89%)
Med to high risk of delay†	9 (31)	4 (11)
	ZIKV exposed (n=26)	ZIKV unexposed (n=30)
Contrast sensitivity			3.063	0.080
Low risk of delay†	20 (77)	28 (93)
Med to high risk of delay†	6 (23)	2 (7)

NA=not applicable because cell sizes were too small to run proportional analyses.

*Cut-off scores for classification of delay risk (<10th percentile) in cognition, fine motor, gross motor, and language domains were obtained from the INTER-NDA international standardisation sample.¹⁷

†Cut-off scores for classification of delays in visual acuity and contrast sensitivity were obtained from the Cardiff standardisation samples.¹⁸

INTER-NDA, INTERGROWTH-21st Neurodevelopment Assessment; logMAR, logarithm of the minimum angle of resolution; ZIKV, Zika virus.