Are women with cervical incompetence at a higher risk of experiencing urinary and pelvic organ prolapse symptoms?

Unravelling the genetic landscape of cervical insufficiency: Insights into connective tissue dysfunction and hormonal pathways

BACKGROUND

The intricate molecular pathways and genetic factors that underlie the pathophysiology of cervical insufficiency (CI) remain largely unknown and understudied.

METHODS

We sequenced exomes from 114 patients in Latvia and Lithuania, diagnosed with a short cervix, CI, or a history of CI in previous pregnancies. To probe the well-known link between CI and connective tissue dysfunction, we introduced a connective tissue dysfunction assessment questionnaire, incorporating Beighton and Brighton scores. The phenotypic data obtained from the questionnaire was correlated with the number of rare damaging variants identified in genes associated with connective tissue disorders (in silico NGS panel). SKAT, SKAT-O, and burden tests were performed to identify genes associated with CI without a priori hypotheses. Pathway enrichment analysis was conducted using both targeted and genome-wide approaches.

RESULTS

No patient could be assigned monogenic connective tissue disorder neither genetically, neither clinically upon clinical geneticist evaluation. Expanding our exploration to a genome-wide perspective, pathway enrichment analysis replicated the significance of extracellular matrix-related pathways as important contributors to CI's development. A genome-wide burden analysis unveiled a statistically significant prevalence of rare damaging variants in genes and pathways associated with steroids (p-adj = 5.37E-06). Rare damaging variants, absent in controls (internal database, n = 588), in the progesterone receptor (PGR) (six patients) and glucocorticoid receptor (NR3C1) (two patients) genes were identified within key functional domains, potentially disrupting the receptors' affinity for DNA or ligands.

CONCLUSION

Cervical insufficiency in non-syndromic patients is not attributed to a single connective tissue gene variant in a Mendelian fashion but rather to the cumulative effect of multiple inherited gene variants highlighting the significance of the connective tissue pathway in the multifactorial nature of CI. PGR or NR3C1 variants may contribute to the pathophysiology of CI and/or preterm birth through the impaired progesterone action pathways, opening new perspectives for targeted interventions and enhanced clinical management strategies of this condition.

Cervical insufficiency a prologue for future pelvic organ prolapse?

BACKGROUND

Preliminary evidence suggests that women with cervical oss insufficiency may have an increased risk to develop pelvic organ prolapse later in life, suggesting a common underlying collagen-oriented mechanism.

OBJECTIVE

The objective of this study was to determine the association between cervical oss insufficiency and the subsequent development of pelvic organ prolapse.

STUDY DESIGN

A matched, case-control study, including women who delivered at the Soroka University Medical Center. Cases were women diagnosed or treated with pelvic organ prolapse (n = 1463), and controls were a representative sample of women of the same age group without pelvic organ prolapse (n = 5637). The association between pelvic organ prolapse and prior preterm birth was tested. Univariate analysis was performed using a conditional logistic regression to assess the association between preterm labor and pelvic organ prolapse. Statistically and clinically significant variables in the univariate analysis were included in the multivariable regression.

RESULTS

The rate of spontaneous preterm birth did not differ between the study groups [pelvic organ prolapse - 4.0% (59/1463) vs. non- pelvic organ prolapse - 4.9% (276/5637), p = 0.16]. The median number of preterm births was higher among women without pelvic organ prolapse (controls) than in those with pelvic organ prolapse (cases) (p = 0.004). Among those who delivered preterm, the individual proportion of preterm deliveries was higher among the controls' group (p = 0.03). Similarly, the rate of cesarean deliveries was also higher among the controls group (p = 0.003). The rate of small for gestational age neonates was higher in the controls group (p = 0.0007), while that of large for gestational age neonates was higher in the case group (p = 0.02). In the univariate analysis, birthweight, vaginal delivery, and prior surgery were associated with subsequent development of pelvic organ prolapse. The multivariable analysis exhibited the same association- having birthweight, vaginal delivery, and all types of prior surgery independently associated with subsequent development of pelvic organ prolapse.

CONCLUSIONS

Obstetrics characteristics associated with pelvic organ prolapse included vaginal delivery and birthweight along with non-obstetrical factors such as prior surgery. There was no association between preterm birth and subsequent development of pelvic organ prolapse. Our findings suggest that the effort during labor at term required for the delivery of appropriate for gestational age or large for gestational age newborns affects the pelvic floor and is a major contributor for the subsequent development of pelvic organ prolapse.

Combination of histochemical analyses and micro-MRI reveals regional changes of the murine cervix in preparation for labor

The cervix is responsible for maintaining pregnancy, and its timely remodeling is essential for the proper delivery of a baby. Cervical insufficiency, or "weakness", may lead to preterm birth, which causes infant morbidities and mortalities worldwide. We used a mouse model of pregnancy and term labor, to examine the cervical structure by histology (Masson Trichome and Picrosirius Red staining), immunohistochemistry (Hyaluronic Acid Binding Protein/HABP), and ex-vivo MRI (T2-weighted and diffusion tensor imaging), focusing on two regions of the cervix (i.e., endocervix and ectocervix). Our results show that mouse endocervix has a higher proportion of smooth muscle cells and collagen fibers per area, with more compact tissue structure, than the ectocervix. With advanced gestation, endocervical changes, indicative of impending delivery, are manifested in fewer smooth muscle cells, expansion of the extracellular space, and lower presence of collagen fibers. MRI detected three distinctive zones in pregnant mouse endocervix: (1) inner collagenous layer, (2) middle circular muscular layer, and (3) outer longitudinal muscular layer. Diffusion MRI images detected changes in tissue organization as gestation progressed suggesting the potential application of this technique to non-invasively monitor cervical changes that precede the onset of labor in women at risk for preterm delivery.