Table 3. Summary of age-related correlation coefficients within the same age groups.

Age group	Sex	N	Correlation coefficient
Fetal stage	Male	4	0.87±0.02
	Female	4	0.93±0.03
	Male and Female	8	0.87±0.04
12 weeks	Male	4	0.93±0.03
	Female	4	0.88±0.04
	Male and Female	8	0.90±0.04
20 weeks	Male	4	0.98±0.01
	Female	4	0.98±0.00
	Male and Female	8	0.98±0.01
30 weeks	Male	3	0.96±0.02
	Female	4	0.94±0.05
	Male and Female	7	0.95±0.03

Average correlation coefficients calculated within the groups of males, groups of females, groups of males and females of the same age. Values are means±SD.