Reference values for C-reactive protein and procalcitonin at term pregnancy and in the early postnatal period

Variability of C-reactive protein limits its clinical utility in the assessment of sepsis but procalcitonin may serve as a valuable biomarker to help rule out infection in pregnancy and postpartum.


Caroline Joyce, Keelin O'Donoghue

Journal Name
Annals of Clinical Biochemistry
Journal Article
Full Citation

Joyce CM, Deasy S, Abu H, Lim YY, O'Shea PM, O'Donoghue K. Reference values for C-reactive protein and procalcitonin at term pregnancy and in the early postnatal period. Annals of Clinical Biochemistry. 2021;58(5):452-460. https://doi.og/10.1177/00045632211005807.

Link to Publication


It is important to detect infection early during pregnancy and following delivery so treatment can be started quickly with better outcomes for women. We looked at two indicators of inflammation and infection, c-reactive protein and procalcitonin. There is limited information available on the normal values for these markers at delivery and immediately after delivery, therefore we sought to establish normal ranges in this setting so abnormal values associated with infection could be recognised. We collected samples from healthy women with uncomplicated pregnancies at delivery and on the first and third day after delivery. We excluded women with twin pregnancies restricting our study to singleton pregnancies instead. In total, 189 women participated and some of these women were recruited at delivery or after giving birth. We recruited some women who had vaginal delivery and some who had surgical assisted delivery (caesarean section). C-reactive protein results in these women showed huge variability making it an unsuitable test for the assessment of infection. Procalcitonin, on the other hand proved to be a highly specific marker for infection. We were able to establish a cut-off level for procalcitonin (0.25 ug/L) which would enable clinicians to rule out infection in pregnancy or after delivery. 

Pregnancy Loss Research Group

Pregnancy Loss Research Group, Department of Obstetrics & Gynaecology, University College Cork, Fifth Floor, Cork University Maternity Hospital, Wilton, Cork, T12 YE02, Ireland,