Table 2.

Univariate analysis for first trimester serum analytes and their association with pre-eclampsia

MoM	Percentile	PEC n=293 (%)	Normal n=3423 (%)	RR (95% CI)	P-value
PAPP-A
<0.46	<5th	23 (7.8)	158 (4.6)	1.6 (1.1–2.4)	0.01
<0.58	<10th	45 (15.3)	318 (9.3)	1.6 (1.2–2.2)	0.001
>2.31	>90th	33 (11.3)	336 (9.8)	1.1 (0.8–1.6)	0.47
>2.83	>95th	15 ( 5.1)	170 (4.9)	1.0 (0.6–1.7)	0.94
Free β-hCG
<0.47	<5th	17 (5.8)	169 (4.9)	1.2 (0.7–1.8)	0.53
<0.56	<10th	29 (9.9)	310 (9.0)	1.1 (0.7–1.5)	0.68
>1.99	>90th	28 (9.5)	340 (9.9)	0.9 (0.6–1.4)	0.78
>2.38	>95th	13 (4.4)	165 (4.8)	0.9 (0.5–1.5)	0.73

^*PEC=pre-eclampsia; RR=relative risk; CI=confidence interval; MoM=multiples of the median