**5.4 Infection in preterm labor**

Caroll et al. assessed the flow in the middle cerebral and umbilical arteries of fetuses and in the uterine arteries of patients with premature rupture of the membranes with or without intrauterine infection. They found no changes in vascular flow, which means that Doppler examination is not useful for monitoring the developing intrauterine infection associated with premature drainage of amniotic fluid [56].

Different results were obtained by Yücel et al. They analyzed vascular flows in patients after premature drainage of amniotic fluid with histopathologically confirmed placental inflammation. The researchers proved that an increase in the systolic-diastolic index in the uterine artery can be considered as a marker of developing intrauterine infection [57].
