Perinatal Correlates of Ureaplasma urealyticum in Placenta Parenchyma of Singleton Pregnancies That End Before 28 Weeks of Gestation

Abstract

OBJECTIVES. The purpose of this work was to examine the relationship between Ureaplasma urealyticum in the placenta and perinatal outcomes in extreme preterm deliveries and to explore the influence of bacteria coinfection on perinatal outcomes in U urealyticum–positive placentas. METHODS. Under sterile conditions, a piece of chorion from 866 singleton deliveries before 28 weeks’ gestation was obtained and flash frozen. The tissue was later homogenized and cultured for Ureaplasma and bacteria. Placentas were also examined histologically. Maternal and neonatal data were obtained prospectively. Each infant had 3 sets of cranial ultrasound scans between days 1 to 4, 5 to 14, and between day 15 and 40th week postconceptional age. Cranial ultrasound findings were by consensus of 2 or 2 of 3 sonologists. RESULTS. U urealyticum was recovered from 6% and bacteria from 47%; 47% of placentas had no bacteria detectable. Sixty-seven percent of Ureaplasma-positive placentas also harbored bacteria. Placentas that harbored U urealyticum only were more likely than sterile placentas to be associated with a higher prevalence of preterm labor and preterm premature rupture of membranes, as well as umbilical cord, fetal vessel, membrane, and parenchymal inflammation and to predict intraventricular hemorrhage and echolucent brain lesions. Placentas that harbored U urealyticum only were similar to placentas that harbored bacteria only. Recovery of U urealyticum and bacteria from same placenta did not enhance the differences between placentas with U urealyticum alone and sterile placentas. Recovery of U urealyticum only was not associated with a higher risk of death before day 7 of life. CONCLUSIONS. The presence of U urealyticum in placental parenchyma before 28 weeks is associated with increased risk of preterm labor and delivery, higher risk of fetal and maternal inflammation, and increased risk of intraventricular hemorrhage and echolucent brain lesions but not of early neonatal death.