Amniotic fluid soluble human leukocyte antigen-G in term and preterm parturition, and intra-amniotic infection/inflammation

Figures & data

Table I.  Demographic and clinical characteristics of patients in the mid-trimester and those at term with and without spontaneous labor.

	Mid-trimester (n = 55)	p*	Term not in labor (n = 50)	Term in labor (n = 50)	p^†
Maternal age (years)	36 (35–38)	<0.01	27 (21–32)	22 (19–27)	<0.01
Gestational age at amniocentesis (weeks)	16 (16–17)	<0.01	39 (38–39)	38.6 (37.9–39.4)	NS
Gestational age at delivery (weeks)	39 (38–40)	NS	39 (38–39)	38.5 (37.9–39.4)	NS
Birthweight (g)	3344 (3113–3604)	NS	3260 (3080–3630)	3375 (3093–3563)	NS

Values are expressed as percentage (number) or median (interquartile range).

NS: not significant.

p*, comparison between patients in the mid-trimester and those at term not in labor.

p^†, comparison between patients at term not in labor and those at term in labor.

Table II.  Demographic and clinical characteristics of patients presenting with spontaneous preterm labor with intact membranes.

	PTL without IAI term delivery (n = 153)	p	PTL without IAI preterm delivery (n = 108)	p*	PTL with IAI preterm delivery (n = 84)	p^†
Maternal age (years)	22 (19–30)	NS	22 (19–30)	NS	23 (20–28)	NS
Smoking	18.4 (28/152)	NS	10.4 (11/106)	0.001	30 (24/80)	0.04
BMI (kg/m^2)	22.7 (20.1–25.5)	NS	22.3 (20.1–25.2)	<0.01	25 (21.8–30)	<0.01
GA at amniocentesis (weeks)	31.9 (29.4–33.3)	NS	31.9 (29.8–33.1)	<0.01	28.8 (25.1–33)	<0.01
GA at delivery (weeks)	38.7 (38–39.7)	<0.01	34.6 (33.3–35.6)	<0.01	29.8 (25.6–33.3)	<0.01
Birthweight (g)	3170 (2900–3515)	<0.01	2330 (1940–2678)	<0.01	1310 (735–2118)	<0.01

Values expressed as percentage (number) or median (interquartile range).

PTL, preterm labor; GA, gestational age; BMI, body mass index; IAI, intra-amniotic infection/inflammation; NS, not significant.

p*, comparison between PTL who delivered preterm without IAI and PTL with IAI.

p^†, comparison between PTL who delivered at term without IAI and PTL with IAI.

Table III.  Demographic and clinical characteristics of patients presenting with preterm prelabor rupture of membranes.

	Preterm PROM without IAI (n = 44)	Preterm PROM with IAI (n = 46)	p
Maternal age (years)	24.5 (20–32.8)	30 (23.5–37.5)	0.008
Smoking	18.2 (8/44)	17.8 (8/45)	NS
BMI (kg/m^2)	24.5 (21.5–28.8)	25.3 (23.5–27.7)	NS
GA at amniocentesis (weeks)	32.6 (29.4–33.8)	30.5 (27.9–32.4)	0.02
GA at delivery (weeks)	33.2 (31.4–34.4)	30.8 (28.7–33.1)	<0.001
Birthweight (g)	2020 (1678–2323)	1645 (1385–2120)	0.02

Values expressed as percentage (number) or median (interquartile range).

PROM, prelabor rupture of membranes; GA, gestational age; BMI, body mass index; IAI, intra-amniotic infection/inflammation; NS, not significant.

Figure 1.  Amniotic fluid concentration of sHLA-G in normal pregnancies at mid-trimester and in those at term not in labor. No significant differences were observed in the median sHLA-G concentration in amniotic fluid between women in the mid-trimester and those with a normal pregnancy at term not in labor [60.7 U/ml, interquartile range (IQR) 28.6–96 vs. 47.6 U/ml, IQR 33.5–69, respectively; p = 0.5].

Figure 2.  Amniotic fluid concentration of sHLA-G in normal pregnancies with and without spontaneous labor at term. Women with spontaneous labor at term had a significantly lower median amniotic fluid sHLA-G concentration than those without labor (36.2 U/ml, IQR 22.9–57.8 vs. 47.6 U/ml, IQR 33.5–69, respectively; p = 0.02).

Figure 3.  Amniotic fluid concentration of sHLA-G among patients with spontaneous preterm labor and intact membranes (PTL). Patients with spontaneous preterm labor with intact membranes with intra-amniotic infection/inflammation (IAI) had a significantly higher median amniotic fluid concentration of sHLA-G than those who delivered preterm without IAI (PTL with IAI: 88.4 U/ml, IQR 43.5–142.9 vs. PTL without IAI: 46.5 U/ml, IQR 26.9–73.9; p < 0.001) and those with spontaneous preterm labor with intact membranes who delivered at term (PTL with IAI: 88.4 U/ml, IQR 43.5–142.9 vs. PTL delivered at term: 50.4 U/ml, IQR 29.8–85.9; p < 0.001). There were no differences in the median amniotic fluid sHLA-G concentration between patients with spontaneous preterm labor without IAI who delivered preterm and those who delivered at term.

Figure 4.  Amniotic fluid concentration of sHLA-G in patients with preterm prelabor rupture of the membranes (preterm PROM). Patients with preterm PROM with IAI had a significantly higher median amniotic fluid sHLA-G concentration than those with preterm PROM without IAI (76.7 U/ml, IQR 39.7–135.4 vs. 46.6 U/ml, IQR 25.8–94.9, respectively; p = 0.004).

Figure 5.  Amniotic fluid concentration of sHLA-G in patients with spontaneous preterm labor with and without histologic chorioamnionitis who delivered within 72 h from amniocentesis. Patients with histologic chorioamnionitis and/or funisitis had a significantly higher median sHLA-G concentration in amniotic fluid than those without histologic inflammation (122.7 U/ml, IQR 79–190.1 vs. 47.7 U/ml, IQR 28.3–83.7, respectively; p < 0.001).