Fetal Thymus Size in Pregnancies Complicated by Preterm Premature Rupture of the Membranes: a case-control study

INTRODUCTION: The aim of this study was to investigate the fetal thymus size in pregnancies complicated by preterm premature rupture of membranes.
METHODS: This prospective case-control study comprised 50 pregnant women aged 18-40 years with active amniotic fluid leakage between 24 and 37 gestational weeks and 60 healthy pregnant women as controls. Anteroposterior diameter of the thymus, transverse thymic diameter, and thymic-thoracic ratio were compared between the study and control groups. Correlations between the thymic-thoracic ratio and maternal and fetal serum inflammation parameters were determined in the case group.
RESULTS: The thymic-thoracic ratio was found to be 0.30±0.06 in pregnancies complicated by preterm premature rupture of the membranes and 0.39 ± 0.08 in the control group (p<0.001). In the case group, the transverse thymic diameter was statistically significantly lower than in the control group (26±7.06 and 35.1±11.9, respectively; p<0.001). There was a statistically significant moderate negative correlation between maternal white blood cell count and fetal thymic-thoracic ratio (r=- 0.318, p=0.010).
DISCUSSION AND CONCLUSION: In pregnancies complicated by preterm premature rupture of the membranes, the fetal thymic-thoracic ratio and fetal transverse thymic diameter were reduced.