Placental mitochondrial DNA content is associated with childhood intelligence

Table 4 Estimated change in intelligence quotient (IQ) for a doubling in mitochondrial DNA content

Intelligence quotient (IQ)	Change in IQ	95% CI	p-value
Total	1.98	0.02 to 3.93	0.05
Verbal	1.42	− 0.51 to 3.34	0.15
Performance	2.29	0.21 to 4.37	0.03

Adjusted for sex, gestational age, birth weight, birth year, zygosity and chorionicity, cord insertion, age at IQ measurement, indicators of socioeconomic status (parental education and neighbourhood household income), smoking during pregnancy and urban environment
CI confidence interval