The multifactorial pathway leading to preterm labor possibly includes the implication of apoptosis. This study aimed to clarify the role of amniotic fluid apoptotic molecules (TNF-alpha, cytochrome C and cell death nucleosomes) at midtrimester as possible predictors of preterm labor (PTL) and/or premature rupture of membranes (PROM).

In this case–control study, comprising 360 women undergoing genetic amniocentesis and out of whom 38 delivered preterm and 18 out of the latter after PROM, the above apoptotic molecules were determined by ELISA. The 38 cases with PTL and 18 cases with PROM were matched for age with 38 and 18 respective controls delivering at term, and the levels of apoptotic molecules were compared.

Cell death nucleosome levels were found to be significantly associated with preterm delivery. Specifically, for every unit increase in nucleosomes, women were on average 0.2% more likely to deliver preterm (OR: 1.002, CI: 1.0–1.003, p = 0.018). In contrast, such an association was not found concerning the other two apoptotic molecules (TNF-a and Cytochrome C).

Second-trimester amniotic fluid cell death nucleosomes’ levels are significantly associated with preterm delivery and could possibly serve as predicting markers.