Tei index to assess fetal cardiac performance in fetuses at risk for fetal inflammatory response syndrome

To examine, in patients with premature rupture of the amniotic membranes (PROM) at < 34 weeks of gestation, the relationship between fetal myocardial performance measured by the Tei index and fetal inflammatory response syndrome (FIRS).

A case-control study was conducted including 15 preterm PROM patients with gestational age between 24 and 33 weeks admitted to Hospital de Clínicas de Porto Alegre, and 15 controls with the same gestational age range. Fetal echocardiography with Doppler was performed at admission for the preterm PROM group, with serial examinations every 7-10 days thereafter until delivery, and at the time of inclusion in the control group. Flow velocity waveforms were obtained for the left ventricle, from which the Tei index was calculated. Placental histopathology and perinatal outcome were compared between the groups.

The left ventricular Tei index was significantly greater in fetuses with preterm PROM compared with controls (0.63 +/- 0.13 vs. 0.51 +/- 0.10, P = 0.007). While there was no difference in isovolumetric times, the left ventricular ejection time was significantly shorter in the preterm PROM group (164 +/- 17 ms vs. 184 +/- 16 ms, P = 0.003). In the preterm PROM group, neonatal sepsis was diagnosed in 73.3%, and funisitis and chorionic vasculitis confirmed FIRS in 53.3%, compared with 6.7% for these three diagnoses in controls (P = 0.001).

These data provide further evidence that cardiac dysfunction is present in the setting of preterm PROM. The study of myocardial performance with the Tei index is a novel non-invasive approach to assess cardiac function and monitor the fetus affected with FIRS.