The paper presents the current status of knowledge about pathology of preterm delivery with presentation of biochemical markers diagnostically useful in prediction of this pathology. Infectious cause of preterm delivery and usefulness of infection diagnostic markers in it's prediction are discussed. Diagnostic potential of immunological inflammatory markers such as IL-6, TNF-alfa and fibronectin and oestriol are emphasised in the context of recently published data. The present status of knowledge doesn't allow for pointing of the most sensitive and specific single predictor of preterm delivery. The most promising are multi-marker investigations performed in pregnancy with risk factors.