Sludge reflects intra-amniotic inflammation with or without microorganisms.

PROBLEM: To investigate whether amniotic fluid (AF) "sludge" in patients with preterm labor (PTL) with intact membranes is related to intra-amniotic infection or inflammation.

METHOD OF STUDY: 105 PTL patients before 29 weeks' gestation were enrolled. AF "sludge" was evaluated by transvaginal sonography. Microorganisms were identified in AF by our newly established PCR method using a eukaryote-made thermostable DNA polymerase.

RESULTS: AF "sludge" was present in 18.1% (19/105) of patients. The results obtained in the AF "sludge" group vs the no "sludge" group were as follows: (i) a similar positive rate of microorganisms in AF by PCR, 31.6% (6/19) vs 38.4% (33/86); (ii) a higher level of AF interleukin-8, 15.2 (0.2-381.5) ng/mL vs 5.8 (0.1-413.7) ng/mL; P = .005); and (3) a higher frequency of histological chorioamnionitis, 52.6% (10/19) vs 23.3% (20/86); P = .010.

CONCLUSION: The presence of AF "sludge" is related to intra-amniotic inflammation with or without microorganisms.