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[Association of PON2 gene polymorphisms in neonates with preterm].

Branch of Institute for Biomedicine,Anhui Medical University,Anqing 246000,China Abstract:The objective is to investigate whether gene polymorphisms in the PON2 gene (PON2148 and PON2311) of neonates are associated with preterm. Using standard questionnaires,194 singleton live born mother-neonate pairs (include preterm cases and term controls) were investigated by the trained field workers with cross-sectional survey at the hospitals in Anqing,Anhui Province,China. Epidemiological and clinical data and blood samples were obtained from 194 mother-neonate pairs. Among neonates,PON2 Ala148Ala homozygote is significantly associated with preterm,compared with Gly148Gly homozygote / Ala148Gly heterozygote before and after adjustment confounders and the same was true for PON2 Ser311Ser homozygote. However,when PON2148 polymorphism and PON2311 polymorphism were considered jointly,no significant gene interaction between PON2148 polymorphism and PON2311 polymorphism in relation to preterm was observed. We draw a conclusion from this research that both PON2148 polymorphism and PON2311 polymorphism in neonates are significantly associated with preterm respectively. But the gene interactions between PON2148 polymorphism and PON2311 polymorphism in neonates are not significantly associated with preterm.

English Abstract↗

[Antibiotic administration in preterm delivery].

DESIGN: Although an association between subclinical intrauterine infection and preterm birth is well established, there is conflicting evidence regarding the benefits of antibiotic administration in women in preterm labor. OBJECTIVES: We attempted to determine the effect of antibioticotherapy in mothers on congenital neonatal infection. MATERIALS AND METHODS: The study group consisted of 1049 pregnant women with imminent preterm labor hospitalized in Clinics of The Research Institute Polish Mother's Memorial Hospital. RESULTS: 244 women delivered preterm and no significant difference in neonatal outcomes could be detected in two groups with intact membranes and preterm premature rupture of membranes. CONCLUSIONS: The results of this study do not support the routine use of antibiotic administration in women with preterm labor.

Adult↗

Role of cytokines in preterm labor and birth.

Preterm birth (defined as delivery prior to 37 weeks' gestation) complicates 5-10% of all births. It is a major cause of perinatal mortality and morbidity. Approximately 20% of all preterm births are iatrogenic resulting from obstetric intervention for maternal and/or fetal indications. Of the remainder, 2/3 are spontaneous preterm labor with or without preterm premature rupture of the membranes (pPROM). Preterm labor is a syndrome rather than a diagnosis since the etiologies are varied. Risk factors include, among others, pPROM, cervical insufficiency, pathologic uterine distention (polyhydramnios, multiple gestation), uterine anomalies, intrauterine infection/inflammation, and social factors (stress, smoking, heavy work). The final common pathway appears to be activation of the inflammatory cascade. Bacterial colonization and/or inflammation of the choriodecidual interface induces production of pro-inflammatory cytokines that, in turn, lead to neutrophil activation and the synthesis and release of uterotonins such as prostaglandins (which cause uterine contractions) and metalloproteinases (that weaken fetal membranes and remodel cervical collagen). This monograph reviews the role of cytokines in the pathophysiology of preterm labor and delivery.

Adolescent↗

[Transvaginal ultrasonography of the cervix length and the prediction of preterm delivery].

OBJECTIVE: To determine if cervical shortening between 12 and 28 weeks gestation predicts risk of spontaneous preterm birth or cervical funneling requiring cerclage. STUDY DESIGN: We reviewed retrospectively all the patients who had transvaginal cervical ultrasound assessment during one year. 43 patients who had a second and early third trimester delivery or cerclage placement were chosen for the study. The control group consisted of 78 patients without signs of preterm labor and cervical shortening as assessed by transvaginal ultrasound. The results of the last ultrasound cervical length measurement were correlated with the likelihood of preterm delivery or cervical funneling requiring cerclage. RESULTS: 26 of 121 patients studied delivered preterm and 15 required cervical cerclage because of cervical shortening and funneling. The mean cervical length assessed by ultrasound was 23.22 +/- 3.07 mm in the group with preterm contractions and delivery and 21.99 +/- 7.05 mm in the group with cervical incompetence. In the normal pregnancy group mean cervical length was 35.59 +/- 3.07 mm. CONCLUSIONS: Cervical length of < 3.0 cm and further shortening of the cervix is predictive of preterm delivery or cervical incompetence requiring cerclage.

Adult↗

Carnitine concentrations in term and preterm newborns at birth and during the first days of life.

Carnitine plays an important role in energetic metabolism. The aim of the study was to characterize the carnitine status in term and preterm newborns with respect to gestational age, birth weight, haematocrit and red blood cell count (RBC). The effect of nutrition on carnitine levels in the first week of life was also studied. Total blood pool of free carnitine (FC), acylcarnitines (AC) and total carnitine (TC) were analysed in whole cord blood and postnatally in capillary blood obtained at the day 4-6 in 33 term newborns and at the day 7-10 in 27 preterm newborns using tandem mass spectrometry. Plasma level of carnitine in the cord blood was measured using radioenzymatic method. Cord plasma levels of FC, AC and TC were higher in preterm newborns in comparison with term newborns (p < 0.01), but the total blood pool of FC and TC in whole cord blood was lower in preterm newborns than in term newborns (p < 0.01) and positive correlation was found between FC and gestational age or birth weight (p < 0.05). In addition, positive correlation was found between AC and red blood cell count or haematocrit (p < 0.05). During the first week of life, blood pool of FC and TC in term newborns and AC and TC in preterm newborns decreased regardless of the type of enteral or parenteral nutrition. Our results indicate that preterm newborns are born with limited carnitine store. Interpretation of carnitine analyses in whole blood relies in addition to gestational age and birth weight on the haematocrit, especially in newborns with anaemia or blood hyperviscosity.

Carnitine↗

Ritodrine in oral maintenance of tocolysis after active preterm labor: randomized controlled trial.

AIM: To assess the efficacy of oral ritodrine in the form of sustained-release capsules for maintenance of uterine quiescence after successful treatment of threatened preterm labor. METHODS: We randomized 120 women with singleton pregnancy who were successfully treated for threatened preterm labor before 34 completed weeks to receive either maintenance tocolysis with two 40 mg ritodrine sustained release capsules three times a day (study group, n=62) or no treatment (control group, n=58) for three days. The primary outcome measure was the recurrent episode of threatened preterm labor within 72 hours, which was defined as regular palpable uterine contractions and change in cervical effacement or cervical dilatation on clinical examination. Secondary outcome measures included the incidence of preterm birth, neonatal adverse outcomes, and maternal side effects. RESULTS: There was no difference in the frequency of recurrent episodes of threatened preterm labor requiring another course of intravenous treatment between the study (8/62) and control (6/58) group of women (P=0.879). No differences were found between the study and control groups in any of the predefined secondary outcome measures, ie, delivery before 37 weeks (13/62 vs 7/58, respectively; P=0.288), delivery before 34 weeks (3/62 vs 1/58, respectively; P=0.682) and birth weight (3037-/+573 g vs 3223-/+423 g, respectively, P=0.862). There were more reported maternal side effects in the study group than in control group (47/62 vs 23/58, respectively; P(<0.001). CONCLUSIONS: Additional maintenance ritodrine therapy was unnecessary in women with singleton pregnancy who had an episode of threatened preterm labor successfully treated with intravenous tocolytic therapy. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00290173.

Administration, Oral↗

From Braxton Hicks to preterm labour: the constitution of risk in pregnancy.

With the recent introduction of preterm birth prevention programs there has been a shift in our understanding of what the presence of contractions during pregnancy means and a reconstituting of risk in ways that position increasing numbers of women at risk for preterm birth. This paper highlights the findings of a study exploring the influences of risk discourses on women's experiences of preterm labour. The primary goals of this institutional ethnographic study were to describe the effects of societal discourses, institutional structures, and nursing work processes on the everyday lives of childbearing women experiencing preterm labour. The findings suggest that risk discourses exert social control over pregnant women and result in fear, guilt, feelings of being judged or punished, and an overwhelming sense of personal responsibility for preventing preterm birth. The study also exposes ways in which biomedical constructions of risk and preterm labour affect the organization of health services, including nursing practice.

Adaptation, Psychological↗

[Fatty acid composition of human milk in mothers of preterm and full-term infants in the first three weeks of lactation].

INTRODUCTION: It is a classical question of infant nutrition whether fatty acid composition of human milk differs in mothers of preterm as compared to those of full-term infants. AIMS AND METHODS: The authors analysed fatty acid composition of milk samples obtained five times during the first month of lactation from mothers of preterm (n = 8, gestational age: 28.0 [4.2] weeks, birthweight: 1235 [420] g, median [IQR]) and full-term (n = 10, gestational age: 38.5 [2.7] weeks, birthweight: 3375 [282] g) infants with high-resolution capillary gas-liquid chromatography. RESULTS: Maternal age, body mass index and eating habits of the mothers did not differ between the two groups. Neither did fat contents of human milk differ between the two groups. Values of linoleic (C18:2omega-6) and alpha-linolenic (C18:3omega-3) acid did not differ. Values of arachidonic acid (C20:4omega-6) and docosahexaenoic acid (C22:6omega-3) were significantly higher following preterm as compared to full-term delivery. Values of the intermediary metabolites g-linolenic acid (C18:3omega-6), dihomo-gamma-linolenic acid (C20:3omega-6), octadecanotetraenoic acid (C18:4omega-3) and eicosatrienoic acid (C20:3omega-3) were also significantly higher in human milk samples of mothers of preterm as compared to those of full-term infants. CONCLUSION: Significantly higher contribution of long-chain polyunsaturated fatty acids in breast milk of mothers giving birth to preterm as compared to full-term infants supports the concept, that preterm infants would benefit more from feeding their own mothers milk than from receiving donor milk.

Adult↗

[Pyridoxal phosphate and activity of pyridoxalkinase in serum of preterm and term infants (author's transl)].

Vitamin B6 nutriture was measured in 14 preterm infants (born between 30th and 35th week of gestation) by means of determination of pyridoxalphosphate and activity of pyridoxalkinase in serum on the 1st and 4th day of life. 11 term infants were included as control group. At the 1st day pyridoxalphosphate and activity of pyridoxalkinase in preterm infants were significantly decreased in comparison with the control group. 50% of preterm infants--all were delivered before the 33rd week of pregnancy--did not show any activity of pyridoxalkinase in serum. On the 4th day, vitamin B6 nutriture of preterm infants was still decreased in comparison with the control group. Measurable activity of pyridoxalkinase, however, was now found in all preterm infants. There was a positive correlation at the 1st and 4th day of life between pyridoxalphosphate and weight and activity of pyridoxalkinase and weight. According to our results pyridoxalkinase is an enzyme which depends on the gestational age of the newborn. After the 32nd week of gestation the enzyme becomes active. Moreover pyridoxalkinase is an enzyme that can be induced by formulas containing vitamin B6. We consider the administration of vitamin B6 to the preterm infant as necessary.

Gestational Age↗

Etiologies of preterm birth in an indigent population: is prevention a logical expectation?

To assess the expectations of preterm birth prevention, we determined the causes of preterm birth in a population of indigent women. We studied 13,119 singleton births in a predominantly black, indigent population occurring between November 1982 and April 1986 to identify the proportion of preterm births that may have been prevented using current treatment modalities. Forty-four percent of the preterm births occurred at 35 to 36 weeks' gestational age, a time when most practitioners do not attempt tocolysis. Of the remainder, 17% occurred before 35 weeks but were indicated for maternal medical or obstetric complications, and another 17% occurred before 35 weeks but followed spontaneous premature rupture of the membranes. Therefore, of the 1445 preterm births, we calculated that only 336 (23.2%) were theoretically preventable. A fourth of these presented at less than 3 cm cervical dilatation and were treated appropriately with tocolytics, but delivered anyway. Therefore, most of the potentially preventable births occurred in the group that presented with cervical dilatation of more than 3 cm. We conclude that improving the preterm birth rate significantly below current levels may be difficult to achieve.

Black People↗

Growth and dietary status of preterm and term infants during the first two years of life.

This study compared growth, food intake and feeding problems in appropriate weight for gestational age sequela-free preterm and term infants at 4, 8, 12 and 24 months adjusted age. Growth deficits were frequent in the preterm infants, especially during the first year of life with a tendency to "catch up" during the second year. Normal head growth and arm muscle area were documented in this selected group of infants but triceps skinfold thicknesses were deficient, especially during the first year. Food consumption patterns and energy intake differed with higher energy intake in the preterm group. Feeding problems were only slightly more frequent in the preterm infants. The only factor associated with energy intake in the preterm infants was duration of neonatal hospital stay. Weight percentile was associated with birthweight and socioeconomic status in term infants, and birthweight, hospital stay and "fussy eater" in preterms at specific ages.

Growth↗

Abnormal FcRIII expression by neutrophils from very preterm neonates.

To further investigate the neutrophil dysfunction of newborn infants, we have measured expression of the neutrophil Fc gamma receptors FcRIII and FcRII in extremely immature preterm neonates born at 24 to 32 weeks of gestation. Fc receptor expression was measured by FACS analysis of cells stained with monoclonal antibody Leu11b for FcRIII and IV-3 for FcRII. "Well" preterm neonates displayed reduced FcRIII, 51.05 +/- 2.0 (mean fluorescence channel +/- SE) when compared with term neonates, 69.24 +/- 5.5 and adult controls, 71.83 +/- 3.0. "Stressed" preterm neonates with severe respiratory distress syndrome or septicemia had a further downregulation of FcRIII, 32.67 +/- 3.0 and 35.75 +/- 1.8, respectively, associated with grossly abnormal cellular fluorescence distribution. In well preterm neonates, expression of FcRIII improved to adult levels during the first two postnatal weeks, suggesting a postnatal maturation of function. Stressed neonates had signs of partial neutrophil activation (increased Mac-1 expression and chemotactic ability), leading us to propose that the further downregulation of FcRIII may be due to receptor shedding in vivo by partially activated cells. FcRII expression was found to be equivalent to adult levels in both well preterm and stressed neonates. Reduced neutrophil FcRIII expression may provide some explanation for the reported abnormalities of phagocytosis and bacterial killing in preterm neonates.

Antigens, Differentiation↗

Prevention of preterm birth: clinical opinion.

Spontaneous preterm delivery continues to be the most significant problem facing clinicians as we enter the 1990s. Prevention of preterm labor still awaits needed improvements in prediction. At present, most preterm birth prevention programs are based upon the early recognition of preterm labor followed by prompt tocolysis. Programs based upon patient education and support, daily contact by trained nurses, intermittent cervical assessment, and daily sampling of uterine activity have been associated with a decrease in preterm birth. The exact contribution of each component to reduce preterm birth remains to be defined and, at present, a combination of the components is still suggested.

Female↗

Preterm birth: a puzzle worth solving.

The incidence of preterm birth has not declined in spite of obstetric and neonatal advances. Although results are variable, the majority of preterm birth prevention programs that embody risk assessment, patient education, and frequent provider visits have shown promise in reducing early births compared with those patients receiving standard care. More recently, home uterine activity monitoring has been shown to be accurate in demonstrating contraction frequency. The combination of this assessment method to detect increased uterine activity at the earliest possible time and intensive perinatal nursing support as to symptomatology related to preterm labor has led to an earlier detection of preterm labor. This, when combined with a comprehensive program of preterm birth prevention, has in many studies resulted in a decrease in the number of early deliveries. To achieve reduction in preterm births, however, these programs must be integrated with aggressive physician management of tocolytic therapy of such patients and continued intensive involvement in such gestations.

Cardiotocography↗

Behavioral and electrophysiological evidence for gestational age effects in healthy preterm and fullterm infants studied two weeks after expected due date.

We investigated the effects of gestational age at birth on behavioral and electrophysiological measures of 135 medically healthy infants, studied at 42 weeks postconception, and stratified into 3 groups--early-born preterms, 26-32 weeks (n = 55); middle-group preterms, 33-37 weeks (n = 43); and fullterms, 38-41 weeks (n = 37). Subjects were studied behaviorally with the Assessment of Preterm Infants' Behavior (APIB) and electrophysiologically with brain electrical activity mapping (BEAM). Fullterms showed significantly better behavioral function than both preterm groups. Less difference was found between the preterm groups. EEG spectral and photic evoked response were of significantly less amplitude for the preterms than the fullterms. Path analysis showed gestational age effects on behavioral (3 of 6) and electrophysiological (13 of 17) variables due to postnatal complications. We conclude that some differences attributable to gestational age at birth are explained by the cumulative effect of minor but unavoidable complications associated with premature birth. We speculate that remaining effects may result from developmentally inappropriate sensorimotor stimulation consequent to the premature experience of an extrauterine environment.

Arousal↗

Home uterine activity monitoring is associated with a reduction in preterm birth.

The value of home uterine activity monitoring plus perinatal nursing support in the prevention of preterm birth among high-risk patients has been demonstrated by several studies. Other reports with less stringent guidelines and less intensive nursing contact have questioned the contribution of home uterine activity monitoring and perinatal nursing support to a preterm birth prevention program. In this large, prospective, randomized multicenter study, patients were assigned to receive either daily monitoring and nursing contact or a preterm birth prevention program including intensive education and more frequent prenatal visits. Among the monitored patients, there was a significant increase in early detection of preterm labor (2 cm or less), successful tocolysis, and prolongation of pregnancy to term. Thirty-one percent of these diagnoses of preterm labor resulted from evaluation of increased uterine activity without associated patient-perceived symptoms. We conclude that a program of daily uterine activity monitoring and perinatal nursing support results in earlier diagnosis of preterm labor and subsequently more effective tocolysis.

Cardiotocography↗

Preventing preterm birth in twin gestation: home uterine activity monitoring and perinatal nursing support.

In this investigation, 45 women with twin gestations in four centers were randomly assigned to either daily home uterine activity monitoring and perinatal nursing support (19) or an education group (26). Patients in the home uterine activity monitoring and perinatal nursing support group monitored uterine activity twice daily, transmitted the data each day, and had 24 hour-a-day access to nursing support. Education patients were counseled regarding the common signs and symptoms of preterm labor. Both groups had scheduled prenatal visits at least every 2 weeks. Sixteen (62%) of the education group and 14 (74%) of the home uterine activity monitoring and perinatal nursing support group developed preterm labor, values that were not significantly different. Of the monitored group who experienced preterm labor, all 14 were dilated 3 cm or less at diagnosis of the first preterm labor, compared with ten of 16 in the education group (P = .01; one-tailed Fisher test). The mean cervical dilatation at the first preterm labor episode in the group receiving daily monitoring and contact (1.6 cm) was significantly less (P = .01) than that in the education group (2.9 cm). Thus, fewer preterm births were recorded in the home uterine activity monitoring and perinatal nursing support group and significantly fewer patients delivered because of failed tocolysis (P = .03).

Adult↗

Uterine contractility patterns after an episode of preterm labor.

Uterine contractility patterns were studied in an attempt to identify those women on tocolytic therapy at risk for preterm delivery. One hundred sixteen women treated successfully after an episode of preterm labor were followed with an ambulatory tocodynamometer system. Contractions were monitored twice daily for 1 hour until delivery or until 36 completed weeks of gestation. In this group, 52 women (45%) delivered preterm and 64 (55%) delivered at term. The analysis revealed that 1) from 24-29 weeks' gestation, there was no significant difference in the uterine activity between the two groups; and 2) beginning at 30 weeks' gestation and continuing until the end of the 36th week of gestation, uterine activity was significantly greater in women destined to deliver preterm. These observations suggest that the patterns of daily uterine contractility observed in patients after an episode of preterm labor can identify those at greater risk for a preterm delivery.

Adult↗