Tissue factor and its natural inhibitor in pre-eclampsia and SGA

Figures & data

Table I.  Demographic and clinical characteristics of the study population.

	Normal pregnancy (n = 86)	Pre-eclampsia (n = 133)	SGA (n = 61)
Maternal age (years)	24 (21–27)	25 (20–31)	25 (20–30)
Gravidity*
1	18 (21.4%)	45 (34.1%)	12 (20.3%)
2–5	53 (63.1%)	71 (53.8%)	39 (66.1%)
≥6	13 (15.5%)	16 (12.1%)	8 (13.6%)
Parity^†
1	46 (54.1%)	96 (72.7%)^‡	38 (63.3%)
2–5	38 (44.7%)	32 (24.3%)	21 (35%)
≥6	1 (1.2%)	4 (3%)	1 (1.7%)
Ethnic origin^§
African-Americans	67 (80.7%)	110 (83.9%)	51 (87.9%)
Caucasian	11 (13.3%)	14 (10.7%)	4 (6.9%)
Hispanic	2 (2.4%)	5 (3.8)	1 (1.7%)
Asian	3 (3.6%)	1 (0.8%)	1 (1.7%)
Other	0	1 (0.8%)	1 (1.7%)
Gestational age at blood collection (weeks)	31.1 (27.4–35)	34.3^‡ (30.2–37.5)	37^‡ (31.0–38.3)
Gestational age at delivery (weeks)	39.6 (38.4–40.7)	34.4^‡¶ (31.1–37.6)	37.4^‡ (33.6–39)
Neonatal birthweight (g)	3343 (3050–3700)	1880^‡ (1200–2680)	2085^‡ (1365–2505)

Data are presented as median (interquartile range) or numbers (%).

SGA, small for gestational age.

*p < 0.05 in comparison to normal pregnancy.

^†Normal pregnancy (n = 85); Pre-eclampsia (n = 132); SGA (n = 60).

^‡Normal pregnancy (n = 84); Pre-eclampsia (n = 132); SGA (n = 59).

^§Normal pregnancy (n = 83); Pre-eclampsia (n = 131); SGA (n = 58).

^¶p < 0.05 in comparison to SGA.

Figure 1. Comparison of median maternal plasma TF concentration between patients with normal pregnancy (n = 79), pre-eclampsia (n = 133), and women who delivered an SGA neonate (n = 61).

Figure 2. Comparison of median maternal plasma TFPI concentration between patients with normal pregnancy (n = 86), pre-eclampsia (n = 133), and women who delivered an SGA neonate (n = 61).

Figure 3. Comparison of maternal plasma TFPI/TF ratio between women with normal pregnancy (n = 79), pre-eclampsia (n = 133), and women who delivered an SGA neonate (n = 61).

Table II.  Multiple logistic regression analysis of the association of maternal plasma tissue factor pathway inhibitor and tissue factor concentrations and pre-eclampsia.

Factor	OR (95% CI)
Gestational age at sample collection (wk)	1.002 (0.996–1.007)
Gestational age at delivery (wk)	1.11 (0.92–1.34)
Tissue factor (pg/mL)	1.004 (1.004–1.005)
Tissue factor pathway inhibitor (ng/mL)	1.076 (1.055–1.097)
Neonatal birthweight (g)	1 (0.996–1.007)
Small for gestational age neonate	7.366 (2.585–20.988)

OR, odds ratio; CI, confidence interval.

Table III.  Multiple logistic regression analysis of the association of maternal plasma tissue factor pathway inhibitor/tissue factor ratio and pre-eclampsia.

Factor	OR (95% CI)
Gestational age at sample collection (wk)	3.64 (1.34–9.9)
Gestational age at delivery (wk)	0.186 (0.057–0.608)
TFPI/TF ratio	0.955 (0.934–0.977)
Neonatal birthweight (g)	1 (0.998–1.001)
Small for gestational age neonate	0.747 (0.083–6.711)

TFPI/TF, Tissue factor pathway inhibitor/Tissue factor; OR, odds ratio; CI, confidence interval.

Table IV.  A comparison of placental histologic lesions between patients with pre-eclampsia and patients who delivered an SGA neonate.

Placental histologic findings	Pre-eclampsia (n = 117)	SGA (n = 49)	p value
Findings consistent with amniotic fluid infection
Chorioamnionitis, maternal response	7 (6)	4 (8.8)	0.73
Funisitis, fetal response	2 (1.7)	4 (8.8)	0.05
Findings consistent with maternal under perfusion
Remote villous infarcts	23 (19.7)	5 (10.2)	0.18
Recent villous infarcts	7 (6)	0	0.11
Increased syncytial knots	65 (55.6)	16 (32.7)	0.01
Villous agglutination	16 (13.7)	8 (16.3)	0.64
Increased intervillous fibrin	29 (24.8)	9 (18.4)	0.42
Decreased placental weight	–	–
Distal villous hypoplasia	32 (27.4)	8 (16.3)	0.17
Persistent muscularisation of basal plate arteries	4 (3.4)	2 (4.1)	1
Mural hypertrophy of decidual arterioles	9 (7.7)	4 (8.2)	1
Acute atherosis of basal plate arteries/decidual arterioles	17 (14.5)	3 (6.1)	0.19
Findings consistent with fetal vascular thrombo-occlusive disease
Early villous stromal-vascular karyorrhexis	1 (0.9)	0	1
Exclusively small foci	6 (5.2)	1 (2)	0.67
Variable size foci	1 (0.9)	2 (4.1)	0.19
Fetal thrombotic vasculopathy	1 (0.9)	1 (2)	0.48
Thrombi, large fetal vessels	0	1 (2)	0.29
Intimal fibrin cushions, large fetal vessels	–	–
Fibromuscullar sclerosis, intermediate size fetal vessels	–	–
Chronic villitis with obliterative fetal vasculopathy	9 (7.7)	6 (12.2)	0.38

Values in parentheses denote percentage.