Second trimester amniotic fluid cytokine concentrations, Ureaplasma sp

33 Background: This study tested if second trimester amniotic fluid cytokine levels, Ureaplasma sp. 34 colonisation and sexual activity predict preterm birth and explain the differential preterm birth rates 35 in Chinese compared to Australian women. 36 Methods: Amniotic fluid was collected by amniocentesis (Chinese 480, Australian 492). Cytokines 37 were measured by multiplex assay and Ureaplasma sp. DNA was detected by PCR analysis. Lifestyle 38 factors, including history of smoking and sexual activity during pregnancy, were obtained through 39 completion of questionnaires upon recruitment to the study. 40 Results: Inflammatory cytokine concentrations were poorly predictive of preterm birth. Ureaplasma 41 sp. was detected in two of the Chinese pregnancies and none from Australia. Sexual activity was less 42 frequent in Chinese, and was not associated with preterm birth or amniotic fluid findings in either 43 population. 44 Discussion: Second trimester amniocentesis for measurement of inflammatory markers and 45 Ureaplasma sp. DNA was not indicative of risk of preterm birth, at least in these populations. The 46 lower rate of preterm birth in China was not explained by differences in amniotic fluid inflammatory 47 markers, Ureaplasma sp. colonisation, or sexual activity. 48