Table 2.

Comparison of MoM levels of serum AFP-L2 and other screening markers during early pregnancy between trisomy 21 and the xontrol group

Group	n	PAPP-A	free β- hCG	NT	AFP-L2
Control	40	0.88 (0.20–3.74)	1.02 (0.33–3.98)	0.87 (0.59–1.15)	1.00 (0.39–2.12)
Trisomy 21	40	0.37 (0.04–1.65)	1.76 (0.15–6.95)	1.17 (0.59–2.10)	1.59 (0.61–3.61)
Z		5.192	3.675	4.197	4.566
P		< 0.001*	< 0.001*	< 0.001*	< 0.001*

PAPP-A pregnancy-associated plasma protein A, free β- hCG free beta-subunit of human chorionic gonadotropin, NT nuchal transparency, AFP-L2 alpha-fetoprotein variants L2, MoM multiple of the median. Data are presented as median (P_2.5–P_97.5); ^*P < 0.001