Second trimester amniotic fluid cytokine concentrations, Ureaplasma sp. colonisation status and sexual activity as predictors of preterm birth in Chinese and Australian women

BACKGROUND This study tested if second trimester amniotic fluid cytokine levels, Ureaplasma sp. colonisation and sexual activity predict preterm birth and explain the differential preterm birth rates in Chinese compared to Australian women. METHODS Amniotic fluid was collected by amniocentesis (Chinese 480, Australian 492). Cytokines were measured by multiplex assay and Ureaplasma sp. DNA was detected by PCR analysis. Lifestyle factors, including history of smoking and sexual activity during pregnancy, were obtained through completion of questionnaires upon recruitment to the study. RESULTS Inflammatory cytokine concentrations were poorly predictive of preterm birth. Ureaplasma sp. was detected in two of the Chinese pregnancies and none from Australia. Sexual activity was less frequent in Chinese, and was not associated with preterm birth or amniotic fluid findings in either population. DISCUSSION Second trimester amniocentesis for measurement of inflammatory markers and Ureaplasma sp. DNA was not indicative of risk of preterm birth, at least in these populations. The lower rate of preterm birth in China was not explained by differences in amniotic fluid inflammatory markers, Ureaplasma sp. colonisation, or sexual activity.