Cervical alterations in pregnancy

Abstract

Spontaneous preterm birth (SPTB), defined as delivery before 37 weeks gestation, remains a significant obstetric dilemma even after decades of research in this field. Although trends from 2007 to 2014 showed the rate of preterm birth slightly decreased, the CDC recently reported the rate of preterm birth has risen for two consecutive years since 2014. Currently, 1 in 10 pregnancies in the US still end prematurely. In this chapter, we will focus on the “compartment” of the cervix. The goal is to outline the current knowledge of normal cervical structure and function in pregnancy and the current knowledge of how the cervix malfunctions leading to SPTB. We will review the mechanisms by which our current interventions are hypothesized to work. Lastly, we will outline gaps in knowledge as well as future research directions that may lead to novel and effective interventions to prevent premature cervical failure and SPTB.

Effects of a gestational level of estradiol on cellular transition, migration, and inflammation in cervical epithelial and stromal cells

“…Cervical ripening is a process needed for a harmless and successful delivery of the fetus 1 . Changes in the cervical extracellular matrix (ECM) during this process lead to decreased tensile strength of the cervix 2–4 . Cervical ripening also involves an inflammatory process characterized by the influx of neutrophils and increased production of inflammatory cytokines such as IL‐6 and IL‐8 5,6 .…”

Term Labor Outcomes after Cerclage Placement in a Multi-institutional Cohort

“…There are differences in collagen remodeling in the cervix among women with cervical insufficiency 7-9 and the mechanism for improved pregnancy outcomes after cerclage placement is unknown. 7 Therefore, we speculate that women who have had a cerclage placed may experience alterations in the biomechanical properties of the cervix which may affect labor outcomes. Of note, large datasets have the potential to identify associations that are statistically significant though may be small in magnitude.…”

“…6 The cervix undergoes biomechanical changes throughout pregnancy, and there are differences in tissue structure among women with cervical insufficiency. [7][8][9] Theoretically, prior cerclage placement could also impact term delivery outcomes through mechanical changes in the cervix. 10,11 However, there is conflicting evidence in the literature of whether cerclage placement affects labor outcomes, including cesarean delivery.…”

The impact of cervical conization size with subsequent cervical length changes on preterm birth rates in asymptomatic singleton pregnancies

“…This CCS impact on PTB rates might be related to a high concentration of neuropeptides, neurotransmitters, oxytocin, and other physiologically active substances in the cervical tissue and lower uterine segment rather than to that in tissues in the upper part of the uterus 63 , 64 . By its modification, the cervix plays an important role during pregnancy and delivery as does the part of the uterine body forming the lower uterine segment 65 , 66 . Subsequently, we suggest that excessive cervical conization might lead to tissue insufficiency and impair cervix structure and function.…”