Contribution of Preterm Delivery to Perinatal Mortality

Rush, R. W.; Keirse, M.J.N.C.; Howat, P; Baum, J D; Anderson, Anne B. M.; Turnbull, A. C.

doi:10.1097/00006254-197710000-00003

Cited by 45 publications

(56 citation statements)

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“…The remaining undigested tissue was subjected to a further incubation in the original digestion mix and the cells obtained were combined with the first batch of isolated cells. Cells were plated at a density of 1.5 ϫ 10 4 cells/cm 2 in 75 cm 2 flasks, allowed to grow to confluence, and passaged using standard methods at a ratio of 1:3. At confluence the medium was removed and fresh medium was added containing either 50 mol/L sodium arsenite (NaArs), 100 mol/L cadmium chloride (CdCl 2 ), 100 mol/L diethylmaleate (DEM), 20 mol/L H 2 0 2 , or medium alone.…”

Section: Induction Of Ho-1 In Myometrial Cell Culturesmentioning

confidence: 99%

“…It is also responsible for up to 75% of neonatal morbidity with considerable long-term morbidity in the child. [1][2][3] Drugs used to treat preterm labor, such as prostaglandin synthesis inhibitors, calcium channel antagonists and ␤-adrenoceptor agonists, have only short-lived effects or have potential side effects for mother and fetus. 4,5 Agents that have been used more recently, such as oxytocin receptor antagonists 6 and nitric oxide (NO) donors, 7 are currently the focus of intensive research, but early reports suggest that they will not confer major benefits.…”

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confidence: 99%

See 1 more Smart Citation

Hemoxygenase and Nitric Oxide Synthase Do Not Maintain Human Uterine Quiescence during Pregnancy

Barber¹,

Robson

Lyall³

1999

The American Journal of Pathology

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The nitric oxide (NO)-cGMP pathway has been proposed as a mechanism for relaxation of myometrium during pregnancy and as a modulator of labor. Carbon monoxide (CO) , produced by hemeoxygenases (HO-1 and HO-2) , also activates soluble guanylate cyclase to increase cGMP. A recent study reported a large increase in HO-1 and HO-2 proteins during pregnancy , suggesting that the HO-CO pathway may be important in the maintenance of uterine quiescence during pregnancy. In this study we used Western blotting , reverse transcription-polymerase chain reaction , and immunohistochemistry to determine HO-1 and HO-2 expression in nonpregnant , pregnant, and laboring myometrium. Immunolocalization of HO was also compared with endothelial and inducible nitric oxide synthases (eNOS and iNOS). In contrast to HO-1 protein , which was not detected in myometrium , HO-2 protein and mRNA were constitutively expressed , although there were no differences in expression between the groups. eNOS was expressed in endothelial cells but not in myometrial smooth muscle. iNOS protein was not detected in myometrium. These data do not support an up-regulation of HO-1 and HO-2 during pregnancy and are not consistent with a role for NO or a major role for CO in human myometrial quiescence. Our results are also in keeping with HO-2 being an noninducible protein. Although spontaneous preterm birth (delivery before 37 weeks) accounts for 5 to 10% of all births, it is associated with up to 70% of neonatal deaths. It is also responsible for up to 75% of neonatal morbidity with considerable long-term morbidity in the child. 1-3 Drugs used to treat preterm labor, such as prostaglandin synthesis inhibitors, calcium channel antagonists and ␤-adrenoceptor agonists, have only short-lived effects or have potential side effects for mother and fetus. 4,5 Agents that have been used more recently, such as oxytocin receptor antagonists 6 and nitric oxide (NO) donors, 7 are currently the focus of intensive research, but early reports suggest that they will not confer major benefits. One reason there is no effective method of treating preterm labor is our limited knowledge of the mechanisms that control myometrial quiescence during pregnancy and its contractile state in normal and preterm labor. 8,9 NO, produced by the enzyme nitric oxide synthase (NOS), binds to the heme prosthetic moiety of the soluble guanylate cyclase, leading to increased cGMP production and smooth muscle relaxation. Carbon monoxide (CO) also binds to heme and activates soluble guanylate cyclase. 10 Discrepancies in localization of NOS and guanylate cyclase in the brain indicate that a substantial portion of guanylate cyclase may not serve as a target for NO. 11 CO is produced by heme oxygenase (HO), a microsomal enzyme that oxidatively cleaves heme, a prooxidant, to produce biliverdin and CO in the presence of NADPH-cytochrome P 450 reductase and NADPH. 12 HO consists of two homologous isoenzymes: HO-1, which is inducible, and HO-2, which is constitutive. 13,14 HO-1 is expressed at high concent...

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Section: Induction Of Ho-1 In Myometrial Cell Culturesmentioning

confidence: 99%

mentioning

confidence: 99%

Hemoxygenase and Nitric Oxide Synthase Do Not Maintain Human Uterine Quiescence during Pregnancy

Barber¹,

Robson

Lyall³

1999

The American Journal of Pathology

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“…In the study by Tomazevic et al [7], they observed that a hysteroscopic correction of intrauterine septa lead to reduced preterm delivery rates and very preterm delivery rates in patients with singleton pregnancies -comparable to levels in control patients. Preterm delivery is significantly associated with intrauterine septa [6][7][8][9][10] and can, therefore, contribute significantly to lower live birth rates [22,23]. In our study, the relative risks of preterm delivery were still higher in the septum patients who had hysteroscopic surgery.…”

Section: Discussionmentioning

confidence: 46%

Perinatal outcomes in singleton and twin ICSI pregnancies following hysteroscopic correction of partial intrauterine septa

Özgür

Bulut

Berkkanoğlu

et al. 2015

J Assist Reprod Genet

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Purpose To investigate the perinatal outcomes of patients with clinical pregnancies from ICSI treatments who had previously undergone hysteroscopic surgery to correct partial intrauterine septa and compare them to outcomes of patients with no intrauterine anomalies. Method A retrospective observational analysis of 2024 ultrasound confirmed pregnancies from ICSI treatments performed between January 2005 and June 2012. The patients were grouped according to their intrauterine status, and subgrouped according to the number of fetal hearts observed; singleton control (n=1128), twin control (n=566), singleton septum (n=217) and twin septum (n=113). The primary outcomes analyzed were miscarriage, preterm, very preterm, stillbirth, vanishing twin and live delivery rates, as well as low birth weight and very low birth weight rates. Result(s) The live birth rate (89,9 %) in the singleton control subgroup was non-significantly higher than the live birth rate (85,3 %) in the septum subgroup, with a RR of 1,05 (p=0, 0583, 95 % CI 0,9943-1,1182) for live birth. In contrast the live birth rate (91,3 %) in twin control subgroup was significantly higher than the live birth rate (84,1 %) in the septum subgroup, with a RR 1,09 (p=0,0282, 95 % CI 0,9988-1, 1819). Non-significantly, higher miscarriage and stillbirth rates were the main contributors to the reduced live birth rates. The singleton and twin septum subgroups also had higher rates of premature and very premature delivery and LBWs and vLBW, especially in the singleton septum subgroup. Conclusion(s) The hysteroscopic correction of intrauterine septa may not eliminate all risks for premature delivery.

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“…The perinatal morbidity and mortality associated with prematurity make this complication all the more significant. It has been estimated that 85% of perinatal deaths not due to congenital anomalies occur in premature infants [13]. Despite the identification of multiple risk factors for premature labor, no clear-cut etiologic mechanism can be identified in the majoritty of patients who deliver prematurely.…”

Section: Introductionmentioning

confidence: 99%

Placental lipid contents in preterm labor complicated by chorioamnionitis

Đelmiš¹

1989

Jpme

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Contribution of Preterm Delivery to Perinatal Mortality

Cited by 45 publications

References 0 publications

Hemoxygenase and Nitric Oxide Synthase Do Not Maintain Human Uterine Quiescence during Pregnancy

Hemoxygenase and Nitric Oxide Synthase Do Not Maintain Human Uterine Quiescence during Pregnancy

Perinatal outcomes in singleton and twin ICSI pregnancies following hysteroscopic correction of partial intrauterine septa

Placental lipid contents in preterm labor complicated by chorioamnionitis

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