Results
Infants born by pre-labour CS had significantly decreased levels of the
inflammatory markers (CRP, MCP-1, IL-18) and the stress-marker HSP70,
and significantly increased levels of the growth factors (VEGF and EGF)
compared to infants born by VD. Comparing pre-labour CS with in-labour
CS showed a similar pattern: CRP, MCP-1 and HSP70 were significantly
decreased, and VEGF was increased, in infants born by pre-labour CS
compared to infants born by in-labour CS. When comparing in-labour CS to
VD, only CRP was significantly different. We found no delivery form
depending differences in neonatal levels of the neurotrophic factors
(S100B, BDNF and NT-3), or the anti-inflammatory marker sTNF RI (Figure
1).
Most biomarkers were different between genders: males had significantly
lower levels than females of the anti-inflammatory marker sTNF RI, the
growth factors (EGF and VEGF), and the neurotrophic factor BDNF. The
inflammatory markers CRP and MCP-1 were higher in males compared to
females. Delivery form has an overall effect on S100B and IL-18 in
males, but not in females. The gender differences were generally more
significant after VD (CRP, MCP-1, sTNF RI, EGF, BDNF, VEGF), than after
in-labour (CRP, BDNF) and pre-labour CS (CRP, VEGF) (Figure 2).
We saw an overall increase of the inflammatory markers CRP, IL-18, and
MCP-1 from GA 37-42, and a decrease of the anti-inflammatory marker sTNF
RI. The stress-marker HSP70 decreased from GA 38-40. The growth factors
EGF and VEGF, and the neurotrophic factor S100B, decreased overall in
samples from GA 37 to 42, while no overall significant difference was
found for the neurotrophic factors BDNF and NT-3 (Figure 3).
There was a significant difference in infants’ birth weight between
delivery forms, where the heaviest infants are born by in-labour CS and
the lightest by pre-labour CS (table 1). Birth weight was included in
the first calculations, but did not make any differences as long as GA
was included in the final model, and thus were excluded in the final
calculation. The maternal BMI was higher for mothers in the CS group (no
matter type) compared to VD, and the maternal age was higher in the
pre-labour CS group compared to the other groups. Neither of the factors
could explain any of the differences found in the biomarkers. The age at
sampling could not explain the differences observed in biomarkers
between the different delivery forms, neither could it explain the
differences in males and females. There were significantly more cases of
PROM before in-labour CS and VD. Removing all cases with PROM did not
change the results.