Amniotic fluid interleukin-6 and the risk of early-onset sepsis among preterm infants.
BACKGROUND
High concentrations of interleukin-6 (IL-6) have been demonstrated in amniotic fluid (AF) from women with intra-amniotic infection. Recent studies have reported that IL-6 levels in AF were related to an increase in neonatal morbidity; moreover, higher IL-6 plasma levels have been observed in neonates with sepsis.


METHODS
A cohort study was carried out at the National Institute of Perinatology in Mexico City. Inclusion criteria were the following: 1) preterm singleton pregnancy; 2) intact membranes at time of enrollment, and 3) written informed consent. Women with other complications of pregnancy were excluded. Newborn sepsis during the first 72 h was defined as early-onset sepsis. Amniotic fluid was obtained at the moment of delivery. Amniotic fluid IL-6 (AF IL-6) was determined by enzyme-linked immunoassays.


RESULTS
Ninety-three women met the criteria for enrollment in the study and 31 (33%) of their newborns had early-onset neonatal sepsis. The mean AF IL-6 in mothers of septic newborns was 5779 +/- 2804 pg/ml compared to 729 +/- 382 pg/ml in mothers with non-infected neonates (p < 0.001). AF IL-6 concentrations higher than 1250 pg/ml were significantly associated with early-onset sepsis (OR 33.3; 95% CI 9.4-117.3) (p < 0.001). Gestational age under 32 weeks was also associated with neonatal sepsis (OR 2.56; 95% CI 1.2-9) (p = 0.002). Women whose infants developed neonatal sepsis had a higher frequency of clinical chorioamnionitis (p = 0.02).


CONCLUSIONS
IL-6 determination in AF may be a useful indicator to identify neonates with higher risk of in utero bacterial infection.
Figueroa-Damián
R
R
Departamento de Infectología e Inmunología, Instituto Nacional de Perinatología, México, D.F., Mexico.
Arredondo-García
J L
JL
Mancilla-Ramírez
J
J
D017668:Age of Onset; D000653:Amniotic Fluid / Q000378:metabolism*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007235:Infant, Premature, Diseases / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism*; D011237:Predictive Value of Tests; D011247:Pregnancy; D012307:Risk Factors; D018805:Sepsis / Q000378:metabolism*
D015850:Interleukin-6