The clinical significance of detecting Ureaplasma urealyticum by the polymerase chain reaction in the amniotic fluid of patients with preterm labor.
OBJECTIVE
This study was undertaken to determine the clinical significance of a detection of Ureaplasma urealyticum by using the polymerase chain reaction (PCR) in the amniotic fluid of patients with preterm labor and intact membranes.


METHODS
Amniocentesis was performed in 257 patients with preterm labor and intact membranes. Amniotic fluid was cultured for aerobic and anaerobic bacteria as well as genital mycoplasmas. U urealyticum was detected by PCR using specific primers. Patients were divided into 3 groups according to the results of amniotic fluid culture and PCR for U urealyticum: those with a negative culture and negative PCR (n=228), those with a negative culture but positive PCR (n=6), and those with a positive culture regardless of the results of PCR (n=23).


RESULTS
The prevalence of positive amniotic fluid culture was 9% (23 of 257). U urealyticum was detected by PCR in 6% (15 of 254) of cases. Of the 15 cases with positive PCR for U urealyticum, amniotic fluid culture was negative in 40% (6 of 15). Patients with a negative culture but positive PCR for U urealyticum had significantly shorter median amniocentesis-to-delivery interval and higher amniotic fluid interleukin-6 and white blood cell count than those with a negative amniotic fluid culture and negative PCR (P<.01 for each). Patients with a positive PCR for U urealyticum but a negative amniotic fluid culture had a higher rate of significant neonatal morbidity than those with a negative culture and negative PCR (P<.05). 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.


CONCLUSIONS
Patients with preterm labor and a positive PCR for U urealyticum but negative amniotic fluid culture are at risk for impending preterm delivery and adverse perinatal outcome.
Yoon
Bo Hyun
BH
Department of Obstetrics and Gynecology, Seoul National University College of Medicine, Seoul, Korea.
Romero
Roberto
R
Lim
June-Hee
JH
Shim
Soon-Sup
SS
Hong
Joon-Seok
JS
Shim
Jae-Yoon
JY
Jun
Jong Kwan
JK
D000328:Adult; D000649:Amniocentesis; D000653:Amniotic Fluid / Q000737:chemistry / Q000166:cytology / Q000382:microbiology*; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D015850:Interleukin-6 / Q000032:analysis; D007958:Leukocyte Count; D009174:Mycoplasma / Q000302:isolation & purification; D007752:Obstetric Labor, Premature / Q000382:microbiology*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D016990:Ureaplasma urealyticum / Q000302:isolation & purification*
D015850:Interleukin-6