Labor SMFM questions

Question 1

what biochemical marker increases the coordiation of contractions for labor.

Answer 1

Gap junctions develop in the myometrium before labor and disappear after delivery. Expression of gap junction protein, connexin-43, in human myometrium is similar in both term and preterm labor.

Question 2

What causes an increase in contractility of the uterus

Answer 2

Increasing evidence suggests that the developing fetus may produce physical and hormonal signals that stimulate macrophage migration to the uterus, with release of cytokines and activation of inflammatory transcription factors, such as nuclear factor κB (NF-κB) and activator protein 1 (AP-1), which also is activated by myometrial stretch. It has been postulated that the increased inflammatory response and NF-κB activation promote uterine contractility via 1) direct activation of contractile genes (e.g. COX-2, oxytocin receptor, and connexin 43) and 2) impairment of the capacity of progesterone receptor to mediate uterine quiescence.