Introduction The most important risk factor for post-partum maternal infection is caesarean section (CS). High-sensitivity C-reactive protein (HS-CRP) accurately detects low concentrations of CRP as a predictor of inflammation in blood. This study evaluated the feasibility of measuring HS-CRP in amniotic fluid (AF) and maternal serum at CS.

Methods This was a prospective observational study of women undergoing elective and emergency CS. AF was obtained at CS by direct needle aspiration from intact amnion. Samples were processed for HS-CRP, bacterial count and culture. Maternal serum CRP was measured before and 3 days after CS.

Results Seventy-nine women undergoing CS participated. In 5 (6%), AF could not be analysed; it was either not obtained or could not be processed due to thick meconium. Of the remainder, 47% (35/74) women underwent elective and 53% (39/74) emergency CS. There was a significant difference in AF HS-CRP levels from elective versus emergency CS (median 68.6 ng.ml vs 192.3 ng.ml; p = 0.009). There was no difference in serum HS-CRP levels between elective and emergency CS. Almost 60% (44/74) of AF samples showed bacterial colonisation. There was no difference in AF or serum HS-CRP levels between patients with sterile amniotic fluid compared to those with bacterial colonisation. However serum HS-CRP levels were higher where AF samples at emergency CS showed bacterial growth (p = 0.03).

Conclusion This study proves the feasibility of measuring HS-CRP in <1 ml amniotic fluid in both elective and emergency settings. AF HS-CRP levels were significantly higher in emergency compared to elective CS. However, analysis of HS-CRP was limited by AF consistency.