Detection ofUreaplasma urealyticumin Second‐Trimester Amniotic Fluid by Polymerase Chain Reaction Correlates with Subsequent Preterm Labor and Delivery

Abstract

Ureaplasma urealyticum is the microorganism most frequently isolated from the amniotic fluid of women in preterm labor. The relationship between intra-amniotic U. urealyticum in healthy second-trimester pregnant women and subsequent pregnancy outcome was investigated. Transabdominal amniotic fluid obtained from 254 asymptomatic women at 15-17 weeks' gestation were tested by polymerase chain reaction (PCR). U. urealyticum was identified in 29 subjects (11.4%). A subsequent preterm labor occurred in 17 U. urealyticum-positive women (58.6%), compared with 10 (4.4%) U. urealyticum-negative women (P<.0001). Preterm birth was documented in 7 (24.1%) U. urealyticum-positive women compared with only 1 U. urealyticum-negative woman (0.4%) (P<.0001). U. urealyticum-positive women also had a higher prevalence of preterm labor in a prior pregnancy (20.7%) than did the negative women (2.7%; P=.0008). PCR testing of second-trimester amniotic fluid for U. urealyticum can identify women at risk for subsequent preterm labor and delivery.

Experimental amniotic fluid infection in sheep: Effects of Ureaplasma parvum serovars 3 and 6 on preterm or term fetal sheep

“…Preterm labour was not a consequence of amniotic fluid ureaplasma colonization. The majority of normal human pregnancies that had amniotic fluid that was PCR positive for Ureasplama at 15-18 weeks gestation also did not deliver prematurely (7,17). Despite the presence of ureaplasmas in the lungs of late gestation lambs and persisting effects on lung development, as indicated by increased surfactant lipid content of 145d lambs, lung function in late gestation was not affected.…”

Mycoplasmas and Ureaplasmas as Neonatal Pathogens

“…However, no significant differences in perinatal outcome were observed between patients with a negative culture but positive PCR and those with a positive amniotic fluid culture (342). Another recent study (93) found that preterm labor occurred in 58.6% women with a positive PCR assay for ureaplasmas at 15 to 17 weeks of gestation compared with only 4.4% of women with negative PCR results, suggesting the potential value of PCR testing of second trimester amniotic fluid to identify women at risk for preterm labor and delivery.…”

Association between Preterm Birth and Vaginal Colonization by Mycoplasmas in Early Pregnancy

“…Ureaplasma has been implicated in infertility, spontaneous abortion, stillbirth, premature birth, low birth weight, and perinatal morbidity and mortality (3). Vaginal colonization with Ureaplasma has not been associated with preterm birth (3), while the presence of Ureaplasma in the amniotic fluid is associated with a robust host response in fetal, amniotic, and maternal compartments (24) and subsequent preterm birth (7). It is not known why this microorganism invades the amniotic cavity only in some women despite heavy colonization of the vagina by Ureaplasma.…”

“…Therefore, U. urealyticum organisms examined in previous studies (3,7,24) may have included both U. parvum and emended U. urealyticum. It is possible that the two new Ureaplasma species differ from each other in pathogenicity, as suggested in several studies (1,18).…”