Hematologic profile of the fetus with systemic inflammatory response syndrome

Roberto Romero, Zeynep Alpay Savasan, Tinnakorn Chaiworapongsa, Stanley M. Berry, Juan Pedro Kusanovic, Sonia S. Hassan, Bo Hyun Yoon, Samuel Edwin, Moshe Mazor

Research output: Contribution to journalArticlepeer-review

51 Scopus citations


The fetal inflammatory response syndrome (FIRS) is associated with impending onset of preterm labor/delivery, microbial invasion of the amniotic cavity and increased perinatal morbidity. FIRS has been defined by an elevated fetal plasma interleukin (IL)-6, a cytokine with potent effects on the differentiation and proliferation of hematopoietic precursors. The objective of this study was to characterize the hematologic profile of fetuses with FIRS. Study design: Fetal blood sampling was performed in patients with preterm prelabor rupture of membranes and preterm labor with intact membranes (n=152). A fetal plasma IL-6 concentration ≥11 pg/mL was used to define FIRS. Hemoglobin concentration, platelet count, total white blood cell (WBC) count, differential count, and nucleated red blood cell (NRBC) count were obtained. Since blood cell count varies with gestational age, the observed values were corrected for fetal age by calculating a ratio between the observed and expected mean value for gestational age. Results: 1) The prevalence of FIRS was 28.9% (44/152); 2) fetuses with FIRS had a higher median corrected WBC and corrected neutrophil count than those without FIRS (WBC: median 1.4, range 0.3-5.6, vs. median 1.1, range 0.4-2.9, P=0.001; neutrophils: median 3.6, range 0.1-57.5, vs. median 1.8, range 0.2-13.9, P<0.001); 3) neutrophilia (defined as a neutrophil count >95 th centile of gestational age) was significantly more common in fetuses with FIRS than in those without FIRS (71%, 30/42, vs. 35%, 37/105; P<0.001); 4) more than two-thirds of fetuses with FIRS had neutrophilia, whereas neutropenia was present in only 4.8% (2/42); 5) FIRS was not associated with detectable changes in hemoglobin concentration, platelet, lymphocyte, monocyte, basophil or eosinophil counts; and 6) fetuses with FIRS had a median corrected NRBC count higher than those without FIRS. However, the difference did not reach statistical significance (NRBC median 0.07, range 0-1.3, vs. median 0.04, range 0-2.3, P=0.06). Conclusion: The hematologic profile of the human fetus with FIRS is characterized by significant changes in the total WBC and neutrophil counts. The NRBC count in fetuses with FIRS tends to be higher than fetuses without FIRS.

Original languageEnglish
Pages (from-to)19-32
Number of pages14
JournalJournal of Perinatal Medicine
Issue number1
StatePublished - 1 Jan 2012
Externally publishedYes


  • Cordocentesis
  • FIRS
  • Hypoxia
  • Infection
  • Neutropenia
  • Neutrophil
  • Neutrophilia
  • Nucleated red blood cells
  • Preterm PROM
  • Preterm labor
  • White blood cell count

ASJC Scopus subject areas

  • Pediatrics, Perinatology, and Child Health
  • Obstetrics and Gynecology


Dive into the research topics of 'Hematologic profile of the fetus with systemic inflammatory response syndrome'. Together they form a unique fingerprint.

Cite this