Preterm delivery is the leading factor causing neonatal mortality and morbidity. We have conducted a PubMed literature search to obtain an update on the etiology, diagnostic problems and therapeutic considerations of preterm delivery. Approximately 5-10% of all births are premature. Preterm labor is associated with preterm rupture of membranes, cervical incompetence, polyhydramnion, fetal and uterine anomalies, infections, social factors, stress, smoking, heavy work and other risk factors. The diagnosis is made on the patients presenting symptoms, clinical findings and of progressive effacement and dilatation of the cervix. Biochemical markers of preterm delivery are of minor importance in daily clinical work. Measurement of the cervix, however, is a practical and valuable tool to predict preterm delivery. Cervical cerclage can be useful in selected cases. Antibiotics may help to prevent preterm labor in cases of known etiologic agents (e.g. preterm rupture of membranes and urinary infection). The use of tocolytic agents such as beta-sympathetic receptor stimulators can be advocated for a few days. There is evidence that their long-term use is not beneficial and could even be harmful to the fetus. Calcium channel blockers (nifedipine) and a new selective oxytocin receptor antagonist, atosiban, appear to be as effective as beta-sympathomimetic drugs on uterine contractions with fewer side-effects. Prostaglandin synthetase inhibitors such as indomethacin may prevent uterine contractions and can be used prior to the 32nd week of pregnancy. A single course of corticosteroid treatment in two doses of 12 mg betamethasone or 6 mg of dexamethasone is important for the prevention of respiratory distress between the 24th and 34th weeks of pregnancy. Multiple doses may be harmful and should be avoided. In these cases management should depend on gestation age (fetal maturity). Uterine contractions after 34 weeks' gestation are not an indication for tocolytic treatment.
Both preeclampsia and the HELLP syndrome have their origin in the placenta. The aim of this study is to review genetic factors involved in development of preeclampsia and the HELLP syndrome using literature search in PubMed. A familial cohort links chromosomes 2q, 5q, and 13q to preeclampsia. The chromosome 12q is coupled with the HELLP syndrome. The STOX1 gene, the ERAP1 and 2 genes, the syncytin envelope gene, and the −670 Fas receptor polymorphisms are involved in the development of preeclampsia. The ACVR2A gene on chromosome 2q22 is also implicated. The toll-like receptor-4 (TLR-4) and factor V Leiden mutation participate both in development of preeclampsia and the HELLP syndrome. Carriers of the TT and the CC genotype of the MTHFR C677T polymorphism seem to have an increased risk of the HELLP syndrome. The placental levels of VEGF mRNA are reduced both in women with preeclampsia and in women with the HELLP syndrome. The BclI polymorphism is engaged in development of the HELLP syndrome but not in development of severe preeclampsia. The ACE I/D polymorphism affects uteroplacental and umbilical artery blood flows in women with preeclampsia. In women with preeclampsia and the HELLP syndrome several genes in the placenta are deregulated. Preeclampsia and the HELLP syndrome are multiplex genetic diseases.
Preterm delivery is the leading factor causing neonatal mortality and morbidity. We have conducted a PubMed literature search to obtain an update on the etiology, diagnostic problems and therapeutic considerations of preterm delivery. Approximately 5-10% of all births are premature. Preterm labor is associated with preterm rupture of membranes, cervical incompetence, polyhydramnion, fetal and uterine anomalies, infections, social factors, stress, smoking, heavy work and other risk factors. The diagnosis is made on the patients presenting symptoms, clinical findings and of progressive effacement and dilatation of the cervix. Biochemical markers of preterm delivery are of minor importance in daily clinical work. Measurement of the cervix, however, is a practical and valuable tool to predict preterm delivery. Cervical cerclage can be useful in selected cases. Antibiotics may help to prevent preterm labor in cases of known etiologic agents (e.g. preterm rupture of membranes and urinary infection). The use of tocolytic agents such as b-sympathetic receptor stimulators can be advocated for a few days. There is evidence that their longterm use is not beneficial and could even be harmful to the fetus. Calcium channel blockers (nifedipine) and a new selective oxytocin receptor antagonist, atosiban, appear to be as effective as b-sympathomimetic drugs on uterine contractions with fewer side-effects. Prostaglandin synthetase inhibitors such as indomethacin may prevent uterine contractions and can be used prior to the 32nd week of pregnancy. A single course of corticosteroid treatment in two doses of 12 mg betamethasone or 6 mg of dexamethasone is important for the prevention of respiratory distress between the 24th and 34th weeks of pregnancy. Multiple doses may be harmful and should be avoided. In these cases management should depend on gestation age (fetal maturity). Uterine contractions after 34 weeks' gestation are not an indication for tocolytic treatment.
The central rationale of tocolysis for preterm labor (PTL) is to delay delivery for at least 48 h to allow for transfer of the mother to a tertiary facility and for corticosteroids to induce surfactant production in fetal lungs. Beta-mimetics decrease the number of women in preterm labor giving birth within 48 h without reducing adverse neonatal outcomes. Calcium channel blockers inclusive of nifedipine decrease the adverse neonatal outcomes by significantly delaying delivery. Atosiban has the best maternal and fetal safety profile but does not seem to reduce neonatal complications. Magnesium sulfate is controversial as a tocolytic, but is valuable as a neuroprotective agent and for treatment of eclamptic seizures. Indomethacin may be a reasonable first choice for acute tocolytsis in gestational ages less than 32 weeks' gestation. Prolonged use (>48 h) should be avoided. Transdermal nitroglycerin can reduce neonatal morbidity and mortality as a result of decreased risk of birth before 28 weeks' gestation. Nifedipine may be a reasonable first choice because it is easy to administer and also of limited side effects relative to β2-mimetics. Tocolysis does not appear to significantly lengthen the gestational age beyond seven days.
Oxidative stress is a consequence of reduction in the antioxidant capacity and excessive production of reactive oxygen and nitrogen species (ROS). Oxidative agents, which are overproduced due to ischemic-reperfusion injury in the placenta, may overwhelm the normal antioxidant activity. This imbalance is a key feature in the pathogenesis of preeclampsia. A decrease in glutathione peroxidase (GPX) activity is associated with the synthesis of vasoconstrictive eicosanoids such as F2-isoprostanes and thromboxane, which are known to be upregulated in preeclampsia. Biochemical markers of lipid peroxidation, such as malondialdehyde and F2-isoprostane in the placenta, are also increased. Adhesion molecules participate in the pathophysiology of preeclampsia by contributing to a reduced invasion by the trophoblast and increased vascular endothelial damage. Superoxide dismutase (SOD), catalase (CAT) and GPX play important roles counteracting oxidative stress. Other antioxidant factors participate in the etiology of preeclampsia. Levels of antioxidants such as Lycopene, Coenzyme 10, as well as some vitamins, are reduced in preeclamptic gestations.
The aim of this study was to determine, in pregnancies complicated by preterm premature rupture of membranes (PPROM), hypertension, intrauterine growth restriction, multi-fetal gestations and pregnancies 23-26 weeks and ≥34 weeks' gestation, whether antenatal corticosteroids benefit the fetus. Literature review using PubMed, Web of Science, Clinical trials.gov, Cochrane Database of Systematic Reviews (1990Reviews ( -2015. Search terms linked special circumstances with corticosteroids. Randomized clinical trials, retrospective and prospective cohort studies, and case control studies were reviewed. In all, 468 abstracts were identified and 84 added from selected article bibliographies; of these, 503 abstracts were excluded, leaving 49 articles as the basis of review. The literature supports corticosteroids for PPROM up to 32-34 weeks without chorioamnionitis. Antenatal corticosteroids are beneficial for preterm infants of women with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome/severe preeclampsia. Postpartum corticosteroid treatment of HELLP patients results in more rapid correction of liver enzymes, platelet counts, and urinary output, which can reduce maternal morbidity. Corticosteroids in twin pregnancies decrease respiratory distress syndrome but the effect is less than in singleton pregnancies. Corticosteroid effects on intrauterine growth restriction pregnancies are conflicting and steroid use should be individualized. Corticosteroid use for 23-26 weeks reduces neonatal mortality but not morbidity.
The rate of disseminated intravascular coagulation (DIC) during pregnancy varies among nations from 0.03% to 0.35%. The existing reports suggest dissimilarity in the underlying mechanisms leading to DIC during gestation. While in developing countries preeclampsia and the HELLP syndrome are prevalent causes of DIC, the leading causes in the developed countries are placental abruption and postpartum hemorrhage. In different cohort studies, DIC is reported in about 12-14% of women with preeclampsia. Nevertheless, it has been suggested that in most cases these women also had a HELLP syndrome and that the occurrence of DIC in women who had only preeclampsia without manifestations of the HELLP syndrome is rare. The aims of this review are to: (1) highlight the mechanisms leading to DIC; (2) describe the changes in the coagulation system during this complication; and; (3) discuss the diagnostic tool and treatment modalities of DIC, in women who develop a HELLP syndrome.
Background:We investigated the association between supplemental folic acid in pregnancy and childhood cancer in a nation-wide study of 687 406 live births in Norway, 1999–2010, and 799 children diagnosed later with cancer.Methods:Adjusted hazard ratios (HRs) compared cancer risk in children by approximated periconceptional folic acid levels (folic acid tablets and multivitamins (0.6 mg), only folic acid (0.4 mg), only multivitamins (0.2 mg)) and cancer risk in unexposed.Results:Any folic acid levels were not associated with leukemia (e.g., high-level folic acid HR 1.25; 95% CI 0.89–1.76, PTrend 0.20), lymphoma (HR 0.96; 95% CI 0.42–2.21, PTrend 0.51), central nervous system tumours (HR 0.68; 95% CI 0.42–1.10, PTrend 0.32), neuroblastoma (HR 1.05; 95% CI 0.53–2.06, PTrend 0.85), Wilms' tumour (HR 1.16; 95% CI 0.52–2.58, PTrend 0.76), or soft-tissue tumours (HR 0.77; 95% CI 0.34–1.75, PTrend 0.90).Conclusions:Folic acid supplementation was not associated with risk of major childhood cancers.
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