Fetal cortisol response to intrauterine microbial colonisation identified by the polymerase chain reaction and fetal inflammation

Abstract

Objective: To determine the fetal cortisol response to intrauterine infection.

Study Design: 16s ribosomal RNA genes or the urease genes of Ureaplasma spps. were identified by the polymerase chain reaction in intrauterine samples. Cord blood cortisol, interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured from 31 infants born at ¡Ü 33 weeks gestation.

Results: 13 infants (median gestation 30 weeks, birthweight 1350g) had at least one positive intrauterine sample for microbial genes whilst 18 (31 weeks, 1320g) did not. Cord blood cortisol was significantly higher in fetuses exposed to intrauterine infection and was significantly increased in fetuses/mothers presenting in preterm labour with intact membranes when compared to infants delivered by elective prelabour caesarean section (CS) (p<0.05). Cord blood cortisol was increased in the mothers with prelabour premature rupture of membranes (pPROM) but this was not significant when compared to the CS group. Cord blood cortisol was significantly increased in the presence of chorioamnionitis or funisitis and was moderately correlated with cord blood IL-6 (R = 0.64, p<0.01) and IL-8 (R=0.52, p<0.01).

Conclusions: Cord blood cortisol was increased in the colonised group when compared to non-colonised infants. It is unclear if infants born in the pPROM group mount an adequate anti-inflammatory response.