Dehydroepiandrosterone sulphate promotes hyaluronic acid-induced cervical ripening in rabbits. (1/94)

Hyaluronic acid (HA) stimulates the synthesis of interleukin (IL) 8, while dehydroepiandrosterone sulphate (DHEA-S) induces the expression of IL-8 and its receptor in the human cervical fibroblast. This has led us to investigate the effect of DHEA-S on HA-induced cervical ripening. Experiments were performed in pregnant rabbits using vaginal suppositories containing 1 mg HA, 30 mg DHEA-S, 30 mg DHEA-S + 0.1 mg HA, 30 mg DHEA-S + 1 mg HA, and 500 microl Witepsol-50 base (control). The effects were evaluated by measuring collagenase, gelatinase and elastase activities, water content, neutrophil infiltration, relative collagen concentration and histological assessment. The activities of collagenase, gelatinase and elastase were significantly increased in rabbits treated with DHEA-S + 1 mg HA compared with rabbits treated with DHEA-S + 0.1 mg HA (P < 0.009, P < 0.001, P < 0.009 respectively). Water content was markedly increased in rabbits treated with DHEA-S + 1 mg HA compared with DHEA-S + 0.1 mg HA treatment (P < 0.05). Neutrophil infiltration was markedly increased, while relative collagen concentration was significantly decreased with DHEA-S + 1 mg HA compared with the DHEA-S + 0.1 mg HA approach (P < 0.001, P < 0.002). The histology of cervices treated with DHEA-S + 1 mg HA showed the density of collagen to be markedly decreased, and collagen fibres irregularly separated. Increased vascularity with massive dilatation of blood vessels was also observed in these rabbits. We conclude that DHEA-S upregulates the HA-induced cervical ripening process.  (+info)

Current trends in cervical ripening and labor induction. (2/94)

Labor is induced in more than 13 percent of deliveries in the United States. Postdate pregnancy is the most common indication. Oxytocin is the drug of choice for labor induction when the cervical examination shows that the cervix is favorable. The use of this agent requires experience and vigilant observation for uterine hyperstimulation, hypertonus or maternal fluid overload. In a patient whose cervix is unfavorable, the use of prostaglandin analogs for cervical ripening markedly enhances the success of inductions. Misoprostol, a prostaglandin E1 analog marketed as a gastrointestinal mucosal protective agent, is safe, efficacious and inexpensive for use in cervical ripening and labor induction. Further studies will better delineate its optimal use. Family physicians need to be familiar with the various methods of cervical ripening and labor induction.  (+info)

Nitric oxide donors stimulate prostaglandin F(2alpha) and inhibit thromboxane B(2) production in the human cervix during the first trimester of pregnancy. (3/94)

Nitric oxide (NO) donors are capable of ripening the human cervix during pregnancy. The purpose of this study was to examine how NO donors may be involved in this process. Cervical biopsies were obtained from pregnant women randomized to receive isosorbide mononitrate (n = 10) or no treatment (n = 10) prior to suction termination. Enzyme-linked immunosorbent assays (ELISA) were performed on culture supernatant for interleukin (IL)-1, IL-6, IL-8, IL-10, IL-15, tumour necrosis factor-alpha, monocyte chemoattractant protein-1 and prostaglandin metabolites. Immunohistochemistry was performed to localize these cytokines, cyclooxygenase (COX)-1, COX-2 and prostaglandin dehydrogenase in cervical tissue and reverse transcription-polymerase chain reaction (RT-PCR) to identify COX-1 and COX-2 expression. Biopsies treated with the NO donor isosorbide mononitrate (IMN) produced significantly greater amounts of prostaglandin F(2alpha) in culture and lower amounts of thromboxane B(2) than controls (572.8 versus 34.9 pg/ml, P < 0.05; 53.3 pg/ml versus 530.9 pg/ml, P < 0.01 respectively). The release of other prostaglandins and of cytokines was not affected by treatment with NO. Inflammatory mediators were localized to cervical tissue and COX-1 and COX-2 expression was confirmed by RT-PCR. In conclusion, the mechanism of NO donor-induced cervical ripening during pregnancy may be mediated in part via increased prostaglandin F(2alpha) synthesis.  (+info)

Male and female isoenzymes of steroid 5alpha-reductase. (4/94)

There are two steroid 5alpha-reductase isoenzymes, designated type 1 and type 2, in mammals and recent experiments show that each plays a unique physiological role. In this article, the hypothesis is developed that the type 1 gene specifies a female isoenzyme, whereas the type 2 gene specifies a male isoenzyme. This idea results from the following observations. First, mutation of the 5alpha-reductase type 1 gene in mice affects reproduction in females by decreasing fecundity and blocking parturition, but has no effect on reproduction in males. Second, mutation of the 5alpha-reductase type 2 gene in mice and men prevents proper virilization but does not affect development or reproductive function in females. Analyses of these diverse phenotypes indicate that the isoenzymes catalyse both anabolic and catabolic reactions in steroid hormone metabolism.  (+info)

Human cervical ripening, an inflammatory process mediated by cytokines. (5/94)

An extensive remodelling process, referred to as cervical ripening, takes place in the cervical tissue during pregnancy and labour. It is recognized as softening and dilation of the cervical canal, and starts as a slow process during pregnancy, becoming rapid close to partum. In this study we focus on cytokines as possible mediators of this final remodelling. mRNA levels for interleukin (IL)-8, IL-6 and granulocyte colony-stimulating factor (G-CSF) were upregulated in the ripe postpartum cervical tissue (n = 8) compared to the unripe state (n = 9). Likewise, released cytokine concentrations increased from non-pregnant (n = 11) to the term-pregnant group (n = 13) with a further increase at partum (n = 16). IL-8 concentrations increased 4-fold from non-pregnant to term-pregnant (P<0.01), and a further 10-fold to postpartum state (P<0.0001). Concentrations of IL-6 and G-CSF were similarly increased. Specific IL-8 immunostaining was identified in the epithelia of pregnant cervical tissue (n = 7) and was most pronounced in the epithelia and stroma of postpartum tissue (n = 4). In conclusion, IL-8, IL-6 and G-CSF increase in the human cervix during the ripening process, indicating their important role in the cervical remodelling. These data demonstrate that cervical ripening is similar to an inflammatory process.  (+info)

Studies of cervical ripening in pregnant rats: effects of various treatments. (6/94)

The exact mechanisms that regulate cervical softening or ripening during pregnancy are not completely understood. The aim of this study was to estimate the effects of various agents on cervical softening during pregnancy in rats. Cervical resistance was examined after treatment with nitric oxide (NO) donors and inhibitors and different hormonal agents. Cervical resistance was significantly reduced (P< 0.05) in rats treated with the NO donors: sodium nitroprusside, molsidomine and prostaglandin E(2). However, treatments with the NO synthase (NOS) inhibitors N(omega)-nitro-L-arginine methyl ester (L-NAME) and L-N(6)-1-iminoethyl-lysine (L-NIL), or the prostaglandin synthesis inhibitor, indomethacin, significantly increased resistance (P<0.05). The antiprogesterone, onapristone, reduced cervical resistance and its effects were only partially blocked by the progesterone agonist, promegestone. Relaxin reduced cervical resistance and NOS inhibitors partially blocked the effect of relaxin. These studies demonstrate that NO regulates cervical ripening. Relaxin also softens the cervix and may act by stimulating NO synthesis. Progesterone seems important in the control of cervical ripening, but its role appears complex. NO and prostaglandin pathways may independently control ripening by acting in parallel or synergistically.  (+info)

Prostaglandin E2 gel In ripening of cervix in induction of labour. (7/94)

A study was done in 75 patients who underwent induction of labour with Prostaglandin E2 gel. All these patients had an unripe cervix. The commonest indications were post-datism, intrauterine growth retardation and pregnancy-induced hypertension. All patients were primigravidas with singleton pregnancy and beyond 35 weeks of pregnancy. The mean Bishop score at the time of instillation was less than three. The improvement of another 2-3 points within six hours and by 7-8 points within 12 hours was found after instillation of the gel. 92% of the patients went into spontaneous labour and 8% required reinstillation. The incidence of failed induction was 1.33%. The mean duration of latent phase was 10.34 hours. Induction delivery time was 16.43 hours. 68.1% patients required augmentation of labour and 31.9% did not require augmentation of labour with oxytocin drip. The incidence of vaginal delivery was 81.33% and that of caesarean section was 17.33%. The commonest indication of caesarean section was foetal distress.  (+info)

The cervix as a predictor of preterm delivery in 'at-risk' women. (8/94)

OBJECTIVE: To examine the relationship between ultrasound-determined cervical status and pregnancy outcome in women 'at-risk' of spontaneous preterm delivery. DESIGN: A prospective cohort study of 120 pregnant women considered to be 'at-risk' of spontaneous preterm delivery by their clinician. Transvaginal ultrasound of the cervix was used to assess overall cervical length, closed endocervical canal length, diameter and internal os dilatation in the second trimester. The main outcome measure was occurrence of spontaneous preterm birth (< 34 and < 37 weeks of gestation). RESULTS: The overall preterm delivery rate (< 37 weeks gestation) in these women was 35% (n = 42) with 20% (n = 24) delivering < 34 weeks gestation. Of the 71 women with a normal cervix, 8 (11%) delivered < 34 weeks, whereas of the 49 women with an abnormal cervix, 16 (33%) delivered < 34 weeks (RR 2.90; 95% CI 1.35-6.24). Using linear regression, closed endocervical canal length of < 21 mm before 20 weeks is associated with delivery < 34 weeks in 95% of women, and with delivery < 37 weeks in 95% of women if the canal length is < 33 mm. Logistic regression showed closed endocervical canal length to be the only significant factor in those women who delivered < 34 weeks after controlling for possible confounders. CONCLUSIONS: A strong relationship is demonstrated between cervical status and pregnancy outcome, particularly the cervical findings before 20 and 24 weeks of gestation. The length of the closed portion of the endocervical canal is the best predictor. A beneficial effect of this approach to 'at-risk' women is the reduction in unnecessary interventions in those with normal cervical findings.  (+info)

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