The continuum of a prolonged labor and a second stage cesarean delivery.

OBJECTIVE: To investigate the association of the timing of primary cesarean delivery with the progress of labor and the operative delivery rate at the subsequent successful trial of labor. METHODS: A retrospective study of women with a primary cesarean and subsequent term cephalic vaginal delivery in two medical centers. Cesarean deliveries were classified as planned, intrapartum first stage or intrapartum second stage. The second stage duration and the operative delivery rate, adjusted to epidural analgesia and oxytocin use, were compared between the groups. χ2 and Kruskal-Wallis tests were used for analysis of categorical and continuous variables, respectively. RESULTS: The study population included 1166 women. The second stage of labor was longer when the previous cesarean delivery occurred during the second stage compared to planned or first stage (1.7 h vs 1.3 h vs 1.3 h, p = 0.005). The proportion of operative deliveries was greater among women with previous cesarean in the second stage of labor (39.6%), compared to planned (26.9%) or first stage (28.8%), p = 0.006. CONCLUSION: Cesarean delivery at the second stage of labor is associated with a longer second stage and an increased operative delivery rate at the subsequent vaginal birth. Our findings attest to the delicate passenger-passage relations that can exist in some parent-couples.

Trained Memory of Human Uterine NK Cells Enhances Their Function in Subsequent Pregnancies.

Natural killer cells (NKs) are abundant in the human decidua, regulating trophoblast invasion and angiogenesis. Several diseases of poor placental development are associated with first pregnancies, so we thus looked to characterize differences in decidual NKs (dNKs) in first versus repeated pregnancies. We discovered a population found in repeated pregnancies, which has a unique transcriptome and epigenetic signature, and is characterized by high expression of the receptors NKG2C and LILRB1. We named these cells Pregnancy Trained decidual NK cells (PTdNKs). PTdNKs have open chromatin around the enhancers of IFNG and VEGFA. Activation of PTdNKs led to increased production and secretion of IFN-γ and VEGFα, with the latter supporting vascular sprouting and tumor growth. The precursors of PTdNKs seem to be found in the endometrium. Because repeated pregnancies are associated with improved placentation, we propose that PTdNKs, which are present primarily in repeated pregnancies, might be involved in proper placentation.