Amniotic fluid CD36 in pregnancies complicated by spontaneous preterm delivery: a retrospective cohort study

Figures & data

Table 1. Maternal and clinical characteristics of women with preterm prelabor rupture of membranes based on the presence and absence of intra-amniotic infection.

Characteristic	Presence of intra-amniotic infection (n = 16)	Absence of intra-amniotic infection (n = 64)	p Value
Maternal age [years, median (IQR)]	35 (30–38)	31 (27–36)	.06
Primiparous [number (%)]	5 (31%)	39 (61%)	.05
Pre-pregnancy body mass index [kg/m^2, median (IQR)]	23.9 (20.3–30.8)	24.2 (20.7–28.6)	.6
Smoking [number (%)]	3 (19%)	8 (13%)	.69
Interval between PPROM and amniocentesis [hours, median (IQR)]	6 (3.3–16.5)	4 (3–10)	.25
Gestational age at admission [weeks + days, median (IQR)]	30 + 4 (26 + 1–32 + 5)	33 + 2 (31 + 1–35 + 0)	.0077
Gestational age at delivery [weeks + days, median (IQR)]	31 + 3 (27 + 2–33 + 1)	34 + 0 (32 + 6–35 + 2)	.0019
Latency between PPROM and delivery [hours, median (IQR)]	91 (25–191)	44 (18–125)	.28
Amniotic fluid IL-6 levels at admission [pg/mL, median (IQR)]	14245 (9182–28415)	796 (417–1689)	<.0001
CRP levels at admission [mg/L, median (IQR)]	6.5 (4.1–14.4)	6.2 (2.8–14)	.32
WBC count at admission [x10^9 L, median (IQR)]	11.2 (9.9–16)	11.8 (9.6–14)	.49
Administration of corticosteroids [number (%)]	14 (88%)	44 (69%)	.21
Spontaneous vaginal delivery [number (%)]	12 (75%)	46 (74%)	>.99
Cesarean delivery [number (%)]	4 (25%)	16 (26%)	>.99
Birth weight [grams, median (IQR)]	1655 (930–2240)	2265 (1800–2500)	.001
Apgar score <7; 5 min [number (%)]	3 (19%)	2 (3%)	.06
Apgar score <7; 10 min [number (%)]	2 (13%)	2 (3%)	.19

Continuous variables were compared using a nonparametric Mann–Whitney U test. Categorical variables were compared using the Fisher’s exact test. Continuous variables are presented as median (IQR) and categorical as number (%). Statistically significant results are marked in bold.

CRP: C-reactive protein; IL-6: interleukin-6; IQR: interquartile range; WBC: white blood cells.

Table 2. Maternal and clinical characteristics of women with spontaneous preterm labor with intact membranes based on the presence and absence of intra-amniotic infection.

Characteristic	Presence of intra-amniotic infection (n = 7)	Absence of intra-amniotic infection (n = 64)	p-value
Maternal age [years, median (IQR)]	34 (29–38)	29 (25–32)	.02
Primiparous [number (%)]	2 (29%)	40 (63%)	.11
Pre-pregnancy body mass index [kg/m^2, median (IQR)]	26 (21.1–36.1)	22.6 (20.1–28.9)	.41
Smoking [number (%)]	3 (43%)	7 (11%)	.05
Gestational age at admission [weeks + days, median (IQR)]	26 + 0 (23 + 0–29 + 5)	29 + 6 (25 + 6–34 + 0)	.06
Gestational age at delivery [weeks + days, median (IQR)]	27 + 0 (24 + 6–29 + 5)	34 + 3 (28 + 4–36 + 6)	.006
Latency from amniocentesis to delivery [days, median (IQR)]	3 (0–13)	11 (0–38)	.21
Amniotic fluid IL-6 levels at admission [pg/mL, median (IQR)]	50000 (16946–50000)	1244 (507–4424)	<.0001
CRP levels at admission [mg/L, median (IQR)]	10.3 (5–37)	5.8 (2.9–14)	.14
WBC count at admission [×10^9 L, median (IQR)]	14.9 (10.7–19.1)	12.9 (9.9–16.1)	.32
Administration of corticosteroids [number (%)]	6 (86%)	46 (72%)	.67
Spontaneous vaginal delivery [number (%)]	6 (86%)	39 (72%)	.66
Birth weight [grams, median (IQR)]	940 (740–1560)	2090 (1100–2710)	.01
Apgar score <7; 5 min [number (%)]	2 (29%)	7 (13%)	.27
Apgar score <7; 10 min [number (%)]	3 (43%)	5 (9%)	.04

Continuous variables were compared using a nonparametric Mann–Whitney U test. Categorical variables were compared using Fisher’s exact test. Continuous variables are presented as median (IQR) and categorical as number (%). Statistically significant results are marked in bold.

CRP: C-reactive protein; IL: interleukin; IQR: interquartile range; WBC: white blood cells.

Table 3. Microbial species identified in the amniotic fluid of women with preterm prelabor rupture of membranes and spontaneous preterm labor with intact membranes.

Preterm prelabor rupture of membranes	Preterm labor with intact membranes
Ureaplasma spp. (n = 12)	Fusobacterium nucleatum (n = 3)
Ureaplasma spp. + Streptococcus anginosus (n = 1)	Ureaplasma spp. (n = 1)
Ureaplasma spp. + Gardnerella vaginalis + Aerococcus christensenii (n = 1)	Ureaplasma spp., Capnocytophaga ochracea, Fusobacterium nucleatum (n = 1)
Ureaplasma spp. + Sneathia spp. + Peptoniphilus incolicus (n = 1)	Staphylococcus epidermidis (n = 1)
Ureaplasma spp. + Sneathia sanquinegens + Lactobacillus iners (n = 1)	Burkholderia cepacia (n = 1)
Ureaplasma spp. + Streptococcus oralis (n = 1)
Escherichia coli (n = 2)
Gardnerela vaginalis (n = 1)
Peptoniphilus indolicus (n = 1)
Enterococcus faecalis (n = 1)
Streptococcus agalactiae (n = 1)
Moraxela osloensis (n = 1)
Streptococcus sanquinis (n = 1)
Sneathia sanquinenges (n = 1)
Mycoplasma hominis (n = 1)
Clostridium perfringens (n = 1)

Figure 1. Amniotic fluid CD36 concentrations in the subgroups of women with PPROM (a) and PTL (b). PPROM, preterm prelabor rupture of membranes; PTL, preterm labor with intact membranes.

Figure 2. Amniotic fluid CD36 concentrations based on the presence of intra-amniotic infection in women with PPROM (a) and receiver operating characteristic curve for amniotic fluid CD36 protein in PPROM women with intra-amniotic infection (b). PPROM, preterm prelabor rupture of membranes.

Data availability statement

The data that support the findings of this study are available from the corresponding author, [Ondrej Soucek], upon reasonable request.