Incidence of invasive ureaplasma in VLBW infants: relationship to severe intraventricular hemorrhage

Abstract

Objective: As Ureaplasmas may be pathogens in preterm infants, this study was conducted to determine the incidence of invasive disease with Ureaplasma parvum and Ureaplasma urealyticum and the relationship with adverse outcomes in a prospective cohort of very low birth weight (VLBW) infants.

Study design: DNA was extracted from the cord or venous blood and cerebrospinal fluid (CSF) samples obtained from 313 VLBW infants. PCR was performed using primers for the mba gene to detect all 14 serovars and then repeated for all positive samples using species-specific primers.

Result: Ureaplasma species were detected in serum and/or CSF samples from 74 of 313 (23.6%) infants. U. parvum was the predominant species (70%). Presence of Ureaplasma was significantly associated with elevated interleukin-1beta in cord blood (odds ratio (OR) 2.6, 1.05 to 6.45, P=0.039). Ureaplasma serum-positive infants had a 2.3-fold increased risk of intraventicular hemorrhage > or =grade 3 (OR 2.50; 1.06 to 5.89, P=0.036).

Conclusion: Invasive Ureaplasma occurs commonly in VLBW infants and may increase the risk for severe intraventricular hemorrhage.

Figure 1

Relationship of Ureaplasma respiratory tract colonization in the first week of life with detection of Ureaplasma in serum and cerebrospinal fluid (CSF) by PCR. PCR to detect Ureaplasma species in serum (white bars) and CSF (hatched bars) was performed in a subset of infantss with known respiratory tract colonization status (tracheal aspirate (TA) or nasopharyngeal (NP)) in the first week of life. The number of PCR-positive infants in each group is shown in black.

Figure 2

Relationship of maternal stage of chorioamnionitis and detection of Ureaplasma species in serum (a) and cerebrospinal fluid (CSF) (b). Number of study infants exposed to different maternal stages of chorioamnionitis with (black) and without Ureaplasma (white). Percentages of Ureaplasma PCR-positive for each stage are noted in each bar. P = 0.008, serum PCR positive vs serum PCR-negative; P = 0.01, CSF PCR-positive vs CSF PCR-negative.