Treatment with an inhibitor of catechol-O-methyltransferase activity reduces preterm birth and impedes cervical resistance to stretch in pregnant rats.
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Catechol-O-methyltransferase (COMT) enzyme catalyzes the methylation of the 2- or 4-hydroxyestrogens to 2- or 4-methoxyestrogens. Both the hydroxyestrogens and methoxyestrogens have been shown to block or enhance the effects of estrogen respectively. Our objective was to investigate the potential role of COMT in parturition and cervical ripening using a rat model. Immunohistochemistry was conducted to detect and localize the COMT protein in rat uterine tissues during pregnancy. We measured the longitudinal changes in urinary 2-hydroxyestrogen before, during, and after pregnancy in rats. Animal studies were conducted to determine the effect of treatment with a selective COMT inhibitor on (1) mifepristone-induced preterm birth and (2) cervical resistance to stretch in pregnant rats. The intensity of staining for the COMT protein differed within the luminal epithelium, uterine gland epithelium, endometrium, and myometrium during pregnancy. Levels of staining for the COMT protein in rat myometrium were highest on day 1 and lowest on days 8 and 13, but high levels returned by days 16 and 19 of pregnancy. The levels of urinary 2-hydroxyestrogen gradually increased in the first 2 weeks of pregnancy, peaked from days 16 to 18 of pregnancy, and then gradually returned to pre-pregnancy levels after delivery. The percentage of pups retained in the uterus of pregnant rats treated with both mifepristone and COMT inhibitor (48 +/- 15%) was significantly higher (P < 0.05) when compared with the value of pregnant rats treated with mifepristone alone (12 +/- 4%). The resistance to stretch was significantly higher (P < 0.05) in cervical tissues from the pregnant rats treated with COMT inhibitor (0.28) when compared with cervical tissues taken from rats treated with vehicle control (0.18). Modulation of COMT activity may play a role in the regulation of myometrial contractility and cervical ripening during pregnancy. (+info)
Ultrasound assessment of cervical length in prolonged pregnancy: prediction of spontaneous onset of labor and successful vaginal delivery.
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Predictors of newborn admission after labour induction at term: Bishop score, pre-induction ultrasonography and clinical risk factors.
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INTRODUCTION: Following labour induction at term, 12 percent of neonates can expected to be admitted to the neonatal intensive care unit. We aimed to evaluate the Bishop score, pre-induction ultrasonography (US) assessment of amniotic fluid, foetal weight and cervical length, and pre-induction and intrapartum risk factors as predictors of neonatal admission. METHODS: 152 women at term, scheduled for labour induction, consented to participate in this prospective study. Transabdominal US was performed to obtain foetal biometry and amniotic fluid index, followed by transvaginal US to measure cervical length. US findings were concealed. The Bishop score was obtained at initiation of labour induction. Pre-induction and intrapartum risk factors were also considered in the multivariate logistic regression analysis. All study women received standard care. RESULTS: On univariate analysis, factors associated with neonatal admission were: gestational age at less than or equal to 40 weeks, labour induction for diabetes mellitus, Bishop score of less than 5 at initiation of labour induction, estimated foetal weight of less than 2.5 kg by US, induction to delivery interval of more than 24 hours, caesarean delivery and umbilical cord blood pH of less than 7.1. Cervical length of greater than 20 mm on transvaginal US (p-value is 0.10) was not significant. After multivariate logistic regression analysis, controlling for the significant variables, only the unfavourable Bishop score (adjusted OR 4.2; 95% CI 1.2-13.8; p-value is 0.02) and caesarean delivery (adjusted OR 3.9; 95% CI 1.1-13.7; p-value is 0.035) were independent predictors of neonatal admission. CONCLUSION: The identification of an unfavourable Bishop score as an independent predictor of neonatal admission is useful in the counselling of women who are considering labour induction. (+info)
Estrogen and progesterone metabolism in the cervix during pregnancy and parturition.
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Selective use of sonographic cervical length measurement for predicting imminent preterm delivery in women with preterm labor and intact membranes.
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Does self-administered vaginal misoprostol result in cervical ripening in postmenopausal women after 14 days of pre-treatment with estradiol? Trial protocol for a randomised, placebo-controlled sequential trial.
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