Table 2.

Comparison of general characteristics between the uninfected screened newborns and the identified congenital cases

	Uninfected screened newborns	Infected cases	p Value	Infected cases with abnormalities at birth†
	n=18 330*	n=66		n=20
Mean±SD of mothers' age (years old)	31.2±4.8	29.7±5.9	NS	30.6±5.0
Mean±SD of gestation age	39w1.9d±1w2.1d	38w3.9d±2w6.1d	NS	38w3.7d±2w5.2d
Mean±SD of birth weight (g)	3002.9±385.2	2756.4±463.7	NS	2589.5±515.0
Proportion of low birth weight (<2500 g), % (95% CI)	7.3 (6.9 to 7.7)	22.7 (14.1 to 34.3)	<0.001	40 (21.8 to 61.4)
Proportion of those small for gestational age‡, % (95% CI)	5.3 (5.0 to 5.6)	18.2 (10.6 to 29.3)	<0.001	30 (14.3 to 52.1)
Proportion of the cases with elder sibling(s), % (95% CI)	48.8 (48.1 to 49.5)	63.6 (51.6 to 74.2)	<0.02	60 (38.6 to 78.2)

^*Uninfected newborns whose information was available from 17 study sites in all six areas.

^†Abnormalities include typical clinical manifestations and abnormalities found in brain imaging (see the text).

^‡<−1.5SD in the distribution in the Japanese standard list of birth weight, which is based on sex, number of pregnancy and gestational age.

d, days; w, weeks.