Table 2.

Clinical characteristics of the study population

Characteristics	Pregnant women carrying trisomy 21 fetuses (n = 12)	Pregnant women carrying normal fetuses (n = 38)	Non pregnant women (n = 6)	P value
Age (years)	32.9 ± 3.5	35.3 ± 4.1	29.5 ± 0.7	0.198a
Body mass index (kg/m2)	21.7 ± 2.5	21.4 ± 2.6	21.1 ± 0.3	0.859a
Gestational age (weeks)	11.8 ± 0.8	12.2 ± 0.6	-	0.182b
Gender-ratio of fetus (male: female)	4:8	14:24	-	-

Data are presented as mean ± standard deviation.

^aone-way analysis of variance test.

^bt-test.