Trimester-specific reference intervals of hemostasis biomarkers for healthy pregnancy

Figures & data

Table 1. Characteristics of the enrolled healthy pregnant and non-pregnant women.

	Number	Age (years)	GA mean (range)
Non-pregnancy	103	27 ± 3
Pregnancy			–
First trimester	128	28 ± 3	11^+3 (4^+0 – 12^+6)
Second trimester	142	29 ± 4	23^+3(14^+0 – 26^+6)
Third trimester	107	29 ± 4	34^+3(27^+0– 35^+6)
Pre-labor	119	28 ± 3	24 h before the labor

GA: gestational age (weeks).

Figure 1. Concentrations of thrombin-antithrombin complex (TAT), α2-plasmininhibitor-plasmin complex (PIC), thrombomodulin (TM) and tissue plasminogen activator-inhibitor complex (tPAI-C) in non-pregnant women (N), first trimester (F), second trimester (S), third trimester (T) and before labor (pre-L). The bars represent the 25th and 75th percentiles with the medians (horizontal lines). the end of the vertical lines represents the 2.5 and 97.5 percentiles. P: p-values.

Table 2. Median and 95% reference intervals for TAT, PIC, TM and tPAI-C of pregnant women and non-pregnant women in trimester-specific groups.

	Non-pregnancy M (P2.5-P97.5)	First trimester M (P2.5-P97.5)	Second trimester M (P2.5-P97.5)	Third trimester M (P2.5-P97.5)	Pre-labor M (P2.5-P97.5)
TAT (1 µg/L)	1.4 (0.5–3.8)	2.1 (0.7–7.6)	4.4 (1.7–12.0)	7.0 (2.7–16.1)	9.3 (4.8–32.9)
		P^a<0.001	P^b<0.001	P^c<0.001	P^d<0.001
PIC (mg/L)	0.5 (0.2–0.8)	0.5 (0.2–0.9)	0.4 (0.2–1.0)	0.3 (0.1–1.4)	0.4 (0.2–1.9)–
					P^d<0.001
TM (TU/mL)	8.5 (3.8–13.1)	6.3 (2.8–11.0)	7.3 (3.7–11.6)	6.9 (2.9–12.9)	8 (4.2–12.6)
tPAI-C (1 µg/L)	6.1 (1.5–10.7)	3.1 (1.2–6.5)	4.7 (2.8–8.8)	4.0 (1.9–8.0)	5.4 (2.8–15.4)
					P^d<0.001

M: median value; P2.5: 2.5th percentile; P97.5: 97.5th percentile.

TAT: thrombin-antithrombin complex; PIC: α2-plasmininhibitor-plasmin complex; TM: thrombomodulin; tPAI-C: tissue plasminogen activator-inhibitor complex; P^a: P value for First trimester vs Non-pregnancy; P^b: P value for Second trimester vs First trimester; P^c: P value for Second trimester vs Third trimester; P^d: P value for Third trimester vs Pre-labor.