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PubMed1997

Influence of nutrition on urinary oxalate and calcium in preterm and term infants.

Few data for normal urinary oxalate (Ox) and calcium (Ca) excretion related both to gestational age and nutritional factors have been reported in preterm or term infants. We therefore determined the molar Ox and Ca to creatinine (Cr) ratios in spot urines from 64 preterm and 37 term infants aged 1-60 days, either fed formula or human milk (HM). Only vitamin D was supplemented; renal or metabolic diseases were excluded. Urinary Ox/Cr ratio was higher in preterm than in term infants, both when formula fed (1st month 253 vs. 180 mmol/mol and 2nd month 306 vs. 212 mmol/mol; P<0.05) or HM fed (206 vs. 169 mmol/ mol and 283* vs. 232 mmol/mol; *P<0.05). Ox/Cr was also higher in formula- than HM-fed preterm infants. The ratio increased during the first 2 months of life irrespective of nutrition. Urinary Ca/Cr ratio was comparable in all groups during the 1st month of life, except for a lower (P < 0.05) value in term infants fed HM (0.10 mol/mol). It increased in all groups during the 2nd month of life, being highest in HM-fed preterm infants (1.86 mol/mol). In conclusion, urinary Ox and Ca excretion is influenced by both gestational age and nutrient intake in preterm and term infants.

Breast Feeding↗

PubMed2006

Preterm birth due to maternal infection: Causative pathogens and modes of prevention.

Preterm birth represents a major problem for modern obstetrics due to its increasing frequency and the accompanying socioeconomic impact. Although several maternal characteristics related to preterm birth have been identified, the etiology in most cases remains inadequately understood. Various microorganisms have been linked to the pathogenesis of preterm birth. Microbes may reach the amniotic cavity and fetus by ascending from the vagina and cervix, by hematogenous distribution through the placenta, by migration from the abdominal cavity through the fallopian tubes, or through invasive medical procedures. Organisms commonly cultured from the amniotic cavity following preterm delivery include Ureaplasma urealyticum, Mycoplasma hominis, Bacteroides spp., Gardnerella vaginalis, Neisseria gonorrhoeae, Chlamydia trachomatis, Trichomonas vaginalis, and group B hemolytic streptococci. Several trials have examined the effect of antibiotic administration to patients with preterm labor and intact membranes, preterm premature rupture of the membranes, genital mycoplasmal infection, asymptomatic bacteriuria, and bacterial vaginosis. The results of such studies, which were variable and often conflicting, are discussed here.

Anti-Bacterial Agents↗

PubMed2006

Teen maternal age and very preterm birth of twins.

BACKGROUND: As teen singleton pregnancy is associated with higher risks of adverse birth outcome, and twin pregnancy, regardless of maternal age, may result in poor outcome, teens pregnant with twins may represent a particularly vulnerable group. However, little has been documented regarding teen twin pregnancy outcome. OBJECTIVE: To characterize the risk of very preterm birth among teens having twins. DESIGN: Cross-sectional analysis of the US 1995-2000 Matched Multiple Birth Data Set. METHODS: We calculated the risk of very preterm birth (<33 weeks' gestation) for teen and young adult mothers of twins (< or =16 years, 17-18 years, 19-20 years), compared to 21-24 year olds, stratified by race/ethnicity. Adjusted odds ratios were estimated controlling for marital status and entry into prenatal care. RESULTS: Odds of very preterm birth decreased significantly with increasing age. Odds ratios ranged from 2.07 (1.73,2.48) to 1.20 (1.11,1.29) according to maternal age for White teen mothers, from 1.76 (1.48,2.09) to 1.13 (1.03,1.24) for Black teen mothers, and from 2.19 (1.77,2.72) to 1.15 (1.02,1.31) for Hispanic teen mothers. Odds of very preterm birth among teen mothers of twins were about the same as those for teen mothers of singletons. CONCLUSIONS: Teens having twins have higher odds of very preterm birth than young adult mothers. However, the association between age and preterm birth was similar among teen mothers having twins as for those having singletons.

Adolescent↗

PubMed1986

Preterm labor: its diagnosis and management.

Preterm labor and delivery remain a significant problem in contemporary obstetric practice. Although the exact cause remains unclear, it is most likely to be multifactorial in nature. No satisfactory screening tool or marker currently exists to firmly establish the diagnosis of impending labor. However, epidemiologic and historical variables associated with preterm delivery show some promise in this regard and are currently being evaluated in preterm prevention programs. Appropriate management of preterm labor mandates early recognition of subtle signs and symptoms; successful therapy is dependent on this issue. The approach to the clinical management of the patient in preterm labor used at our institution is described. Therapy with beta-adrenergic receptor agonists is currently the recommended pharmacologic treatment of this disorder. A review of other tocolytic agents and their usefulness in the management of preterm labor are presented.

Adolescent↗

PubMed1989

The incidence of positive amniotic fluid cultures in patients preterm labor with intact membranes.

The possible relationship between intrauterine infection and preterm labor has received considerable attention in recent years. The purpose of this study was twofold: first, to determine the frequency of asymptomatic infection in patients who came to the hospital in preterm labor, and second, to determine the significance of a positive amniotic fluid culture in relation to latency period and likelihood of preterm delivery. Patients who came to the hospital in preterm labor with intact membranes between 20 and 35 weeks' gestation underwent transabdominal amniocentesis. Amniotic fluid was sent for Gram stain and culture. Patients received tocolytic therapy as clinically indicated. Of 127 patients cultured, seven (5.5%) had positive amniotic fluid cultures. These patients had a significantly decreased latency period from amniocentesis to delivery (4.4 days versus 28.6 days), and a significantly increased chance of being delivered of preterm infants (100% versus 52.5%), as compared with patients with negative cultures. The rate of positive Gram stain was 7 of 125 positive. However, there was no correlation between positive Gram stain and positive culture results. Similarly, positive Gram stain results were not associated with any difference in the latency period or rate of preterm delivery.

Amniocentesis↗

PubMed1990

Infection and labor. VI. Prevalence, microbiology, and clinical significance of intraamniotic infection in twin gestations with preterm labor.

The purpose of this study was to establish the prevalence, microbiology, and outcome of microbial invasion of the amniotic cavity in twin gestation presenting with preterm labor and intact membranes. Amniocenteses were performed on both sacs of 46 women with twin gestations, preterm labor, and intact membranes. Indigo carmine was injected to ensure sampling of both amniotic sacs. Amniotic fluid was cultured for aerobic and anaerobic bacteria, Mycoplasma hominis, and Ureaplasma urealyticum. A positive amniotic fluid culture of at least one sac was noted in 10.8% (5/46) of patients admitted in preterm labor and in 11.9% (5/42) of women delivered of preterm neonates. Of the five patients with microbial invasion of the amniotic cavity, three had microorganisms isolated from both sacs. The presenting sac was involved in all cases, supporting an ascending route for microbial invasion of the amniotic cavity in twin gestation. Polymicrobial infection was found in three of the eight amniotic sacs with positive cultures. In two cases different organisms were isolated from each sac. All patients with positive amniotic fluid cultures were delivered of preterm infants within 48 hours of amniocentesis. Patients with positive amniotic fluid cultures presented with preterm labor at an earlier gestational age and with more advanced cervical dilatation than did women with negative amniotic fluid cultures. Clinical evidence of chorioamnionitis subsequently developed in two of five women with positive amniotic fluid cultures. The interval between amniocentesis and delivery was shorter in women with positive amniotic fluid cultures than in women with negative amniotic fluid cultures (median: 3.5 vs 168 hours, p less than 0.0001). Infants born to women with microbial invasion of the amniotic cavity had a lower median birth weight and a higher incidence of respiratory distress syndrome than those born to women with negative amniotic fluid cultures (birth weight: 1085 vs 1975 gm, p = 0.024; respiratory distress syndrome: 37.5% vs 8.3%, p = 0.04).

Amniotic Fluid↗

PubMed1991

Uterine activity after preterm premature rupture of the membranes.

Preterm premature rupture of the membranes complicates few pregnancies but is a major contributor to overall perinatal morbidity and mortality. Although a reduced incidence of preterm premature rupture of fetal membranes has been reported in women who had antepartum uterine activity monitoring, there are few data regarding uterine activity after preterm premature rupture of fetal membranes. Therefore daily uterine activity monitoring was performed in 101 consecutive women with preterm premature rupture of fetal membranes between 26 and 34 weeks' gestation. The mean gestational ages at rupture and delivery were 31.4 +/- 2.3 and 33.7 +/- 4.5 weeks, respectively. A significant increase in contraction frequency was identified within 24 hours of onset of preterm labor (p less than 0.005). A contraction frequency of four or more per hour predicted the onset of labor within 24 hours with a sensitivity of 72%, a specificity of 90%, a positive predictive value of 54%, and a negative predictive value of 95%. These results indicate that most women with preterm premature rupture of fetal membranes exhibit a baseline contraction frequency that is similar to that of women with intact membranes and premature labor. An abrupt increase in contraction frequency is a warning of impending labor.

Adult↗

PubMed1991

Multicenter randomized clinical trial of home uterine activity monitoring for detection of preterm labor.

Home uterine activity monitoring has been described as an effective means of detecting uterine contractions, but controversy exists whether it is home uterine activity monitoring or increased nursing support in conjunction with it that contributes to earlier detection of preterm labor. In this study 377 women at risk for preterm labor from three centers were prospectively, randomly assigned to high-risk prenatal care alone (not monitored) or to the same care with twice-daily home uterine activity monitoring without increased nursing support (monitored). The two groups were medically and demographically similar at entry into the study. Routine visits, nonroutine visits, and gestational age at diagnosis of preterm labor were similar in both groups. Preterm labor occurred in 41 of 198 monitored and 39 of 179 not monitored patients. Mean cervical dilatation was 1.4 cm in 41 monitored compared with 2.5 cm for 37 not monitored (p = 0.0006); 73.1% of monitored and 27.5% of not monitored had preterm labor detected before 2 cm dilatation (p = 0.00009). Neonatal outcome of singleton pregnancies showed greater birth weight, fewer days in the neonatal intensive care unit, and fewer babies requiring oxygen therapy and mechanical ventilation in the monitored group. The better outcomes are probably due to the increased likelihood of diagnosis of preterm labor before advanced cervical dilatation with home uterine activity monitoring, thus providing the clinician with a better chance to initiate tocolytic therapy directed at improving pregnancy outcome.

Birth Weight↗

PubMed1992

Tumor necrosis factor in preterm and term labor.

OBJECTIVE: Our objective was to determine if labor (term and preterm) and microbial invasion of the amniotic cavity were associated with changes in amniotic fluid concentrations of tumor necrosis factor. STUDY DESIGN: Amniotic fluid was retrieved by transabdominal amniocentesis from 269 women in the following groups: midtrimester (n = 38), preterm labor with intact membranes (n = 52), preterm premature rupture of membranes (n = 74), term in active labor (n = 84), and term not in labor (n = 21). Fluid was cultured for aerobic and anaerobic bacteria and for Mycoplasma species. Tumor necrosis factor was measured with a commercially available enzyme-linked immunosorbent assay validated for amniotic fluid (sensitivity 60 pg/ml). RESULTS: Amniotic fluid from pregnant women in the second and third trimesters who were not in labor did not contain tumor necrosis factor. Among women in preterm labor, 92.3% (12/13) of patients with a positive amniotic fluid culture had detectable tumor necrosis factor in the amniotic fluid (median 820 pg/ml, range less than 60 to 2340 pg/ml). In contrast, only 10.2% (4/39) of women with a negative amniotic fluid culture had detectable tumor necrosis factor. Histopathologic chorioamnionitis was found in all patients who had a positive amniotic fluid culture, and tumor necrosis factor was detectable in the amniotic fluid of all but one of these patients. Among women in active labor at term, 25% (21/84) had detectable tumor necrosis factor in the amniotic fluid. Tumor necrosis factor was detected more frequently in the amniotic fluid of patients with a positive amniotic fluid culture than in patients with a negative culture (46.6% [7/15] vs 20.2% [14/69], p = 0.047). Amniotic fluid concentrations of tumor necrosis factor were significantly higher in patients with preterm premature rupture of membranes, labor, and a positive amniotic fluid culture than in the other subgroups of patients with preterm premature rupture of membranes. CONCLUSION: Parturition in the setting of microbial invasion of the amniotic cavity is associated with activation of the cytokine network as demonstrated by the detection of tumor necrosis factor in human amniotic fluid.

Adult↗

PubMed1992

Oral magnesium and the prevention of preterm labor in a high-risk group of patients.

OBJECTIVE: The null hypothesis of this study is that treatment with oral magnesium gluconate 1 gm four times daily will not decrease the rate of preterm labor and delivery in a high-risk group of pregnant women. STUDY DESIGN: Fifty-four women at risk for preterm delivery were selected randomly to receive magnesium gluconate 1 gm orally four times daily or placebo. These women were monitored prospectively for signs and symptoms of preterm labor. A subgroup of 31 women also received a home uterine activity monitor. The serum magnesium level was measured initially and again 2 weeks after study enrollment. The data were analyzed with Fisher's exact test and analysis of variance. RESULTS: Preterm labor developed in 15 women in the placebo group and in 16 women in the magnesium group. There were no differences in birth weight or gestational age at delivery. The mean increase in serum magnesium level while the patients were taking magnesium gluconate was 0.10 mg/dl (p = not significant). Five women did not have an increase in serum magnesium level and preterm labor developed in all of them. CONCLUSION: Magnesium gluconate in a dose of 1 gm four times daily is not effective for preventing preterm delivery in a high-risk group of patients.

Administration, Oral↗

PubMed1993

Neutrophil attractant/activating peptide-1/interleukin-8: association with histologic chorioamnionitis, preterm delivery, and bioactive amniotic fluid leukoattractants.

OBJECTIVES: The goals of this study were (1) to determine immunoreactive neutrophil attractant/activating peptide-1/interleukin-8 levels in amniotic fluid from patients with preterm labor and (2) to compare neutrophil attractant/activating peptide-1/interleukin-8 levels, amniotic fluid culture, Gram stain, and the leukotaxis bioassay for their ability to predict histologic chorioamnionitis and clinical outcome. STUDY DESIGN: Amniotic fluid was collected by amniocentesis from 55 patients with idiopathic preterm labor and three patients with preterm labor and clinical chorioamnionitis. Gram stain, culture (aerobic, anaerobic, and Mycoplasma species), leukotaxis bioassay, and a commercially available neutrophil attractant/activating peptide-1/interleukin-8 enzyme-linked immunosorbent assay (sensitivity 1 ng/ml) were performed on the amniotic fluid samples. Placentas and chorionic membranes were evaluated for evidence of histologic chorioamnionitis in patients delivered preterm. RESULTS: All patients with detectable leukoattractants by the leukotaxis bioassay had neutrophil attractant/activating peptide-1/interleukin-8 levels above the threshold of the assay. The presence of amniotic fluid neutrophil attractant/activating peptide-1/interleukin-8 is a more sensitive marker for histologic chorioamnionitis and delivery before 34 weeks than is amniotic fluid culture (100% vs 59%, p < 0.01; and 95% vs 56%, p < 0.01, respectively). Also, of patients in idiopathic preterm labor those without amniotic fluid leukoattractants (group 1) had the lowest amniotic fluid levels, followed by patients with amniotic fluid leukoattractants and a negative culture (group 2) and patients with amniotic fluid leukoattractants and a positive culture (group 3) who had the highest levels (group 1 vs group 2, p < 0.001; group 2 vs group 3, p < 0.01). CONCLUSIONS: Amniotic fluid neutrophil attractant/activating peptide-1/interleukin-8, like the leukotaxis assay, is an accurate antepartum predictor of histologic chorioamnionitis and subsequent early delivery in patients with preterm onset of labor. This study supports the role of neutrophil attractant/activating peptide-1/interleukin-8 in the recruitment of neutrophils into chorionic membranes and placenta during developing intrauterine infection.

Amniocentesis↗

PubMed1993

Preterm birth prevention: where are we?

OBJECTIVE: The purpose of this study was to review the current approaches to preventing preterm delivery. STUDY DESIGN: The problem of preterm birth was assessed by reviewing the different components that play a role in preterm birth prevention, excluding infection, antibiotic treatment, and tocolytic treatment. RESULTS: Prevention of preterm labor must initially discriminate those at risk. Positive predictive values of various approaches are currently not adequate enough to warrant intervention. Prevention modalities, in part because of poor prediction, are mostly unproved. Accurate diagnoses of preterm labor remains difficult and confuses analyses of tocolytic agents. Cervicovaginal fetal fibronectin, perhaps in combination with cervical evaluation, shows promise. Early detection programs remain controversial, but most reviews indicate that daily patient contact with high-risk patients gives cause for some optimism. Antenatal maternal glucocorticoid treatment at specific gestational ages improves neonatal outcome. CONCLUSION: The incidence of preterm birth is rising in the country. However, improved definition of the various components of the problem has provided an improved understanding of the problem. There is a new continuing effort and a search for new and innovative ways to address this vexing national problem.

Australia↗

PubMed1993

Relationship of circadian rhythms of uterine activity with term and preterm delivery.

OBJECTIVE: Our aim was to document the presence or significance of circadian uterine activity rhythms in pregnant women who delivered at term and preterm. STUDY DESIGN: We measured uterine activity in 19 women divided into a control group (low risk for preterm labor, term delivery, n = 7), a group at high risk for preterm labor, term delivery (n = 6), and a group at high risk for preterm labor, preterm delivery (n = 6). Patients were hospitalized for 24 hours every 2 weeks from 26 weeks' gestation until delivery. Uterine activity was measured continuously by external tocodynamometer. RESULTS: Patients delivering at term demonstrated a nocturnal surge (4 to 7 AM) in uterine activity the last 80 days before delivery (p < 0.05, analysis of variance). Patients delivered preterm showed an initial nocturnal surge of uterine activity similar to those delivered at term, but this disappeared 24 days before delivery (p > 0.05, analysis of variance). CONCLUSION: Uterine activity nocturnal surges normally precede term delivery. These surges are lost in women who deliver prematurely.

Adult↗

PubMed1993

Oncofetal fibronectin in patients with false labor as a predictor of preterm delivery.

OBJECTIVE: Our objective was to determine whether fetal fibronectin is a discriminator for preterm labor and early delivery in women who have intact membranes and uterine activity. STUDY DESIGN: In our prospective study 28 women between 24 and 34 weeks' gestation with regular, persistent uterine contractions (> 10/hr) and intact membranes were assessed for presence of fetal fibronectin. A Dacron swab was applied to the external os for 10 seconds. The cervix was < or = 1 cm, and all patients were diagnosed as having false labor. The assay was performed by using monoclonal antibody FDC-6 to bind fetal fibronectin. RESULTS: Of the 28 patients with false labor, 14 had a positive fetal fibronectin, and all had preterm labor (specificity and positive predictive value 100%). Of these, nine delivered preterm, yielding a specificity and positive predictive value of 72% and 64%, respectively. Among the 14 women with a negative fetal fibronectin, only four developed preterm labor (sensitivity 78%, negative predictive value 71%). One patient delivered preterm at 34 weeks (sensitivity 90% and negative predictive value 93%). CONCLUSIONS: A positive fetal fibronectin in women who have false labor indicates a significant risk for preterm labor and early delivery. A negative fetal fibronectin is a reassuring sign.

Adult↗

PubMed1995

Newborn complications after intrapartum asphyxia with metabolic acidosis in the preterm fetus.

OBJECTIVE: Our purpose was to determine the nature of the complications in preterm newborns after intrapartum fetal asphyxia with metabolic acidosis at delivery. STUDY DESIGN: Thirty-seven preterm fetuses with metabolic acidosis were matched with 37 preterm fetuses with normal blood gas measurements at delivery. A complication score expressed the magnitude of newborn complications during the 10 days after delivery. RESULTS: The mean complication score for the preterm newborns at 32 to 36 weeks in the asphyxia group, 9.6, was significantly greater than that for the control group, 3.1. Fetal asphyxia was associated with severe complications in all systems. The complication scores for the preterm newborns < 32 weeks in the asphyxia group were of the same order as the control group. This may be related in part to a short duration of the asphyxial insult. The Apgar score at 1 minute was a valuable predictor of newborn complications in both the asphyxia and control groups. CONCLUSIONS: Intrapartum fetal asphyxia with metabolic acidosis at delivery is an important factor in the occurrence of severe complications, particularly in the central nervous system, respiratory system, and kidney, of preterm newborns.

Acidosis↗

PubMed1995

The irritable uterus: a risk factor for preterm birth?

OBJECTIVE: Our aim was to determine the incidence and preterm delivery rate along with the indication for delivery in patients with uterine irritability. STUDY POPULATION: In this retrospective, descriptive study, 17,186 patients with well-defined high-risk factors were compared with 2637 women with uterine irritability. RESULTS: The incidence of preterm labor in patients with uterine irritability was 18.7%, significantly less than in those with other high-risk factors (odds ratio 0.35, 0.31 < odds ratio < 0.38). However, women with uterine irritability who experience preterm labor, compared with other high-risk factors, are much more likely to deliver before 34 weeks' gestation (odds ratio 2.50, 2.07 < odds ratio < 3.03) and more than twice as likely to deliver as a result of advanced preterm labor or membrane rupture (odds ratio 2.20, 1.75 < odds ratio < 2.78). CONCLUSIONS: The incidence of preterm labor in women with uterine irritability is not as frequent as in patients with other high-risk factors. However, preterm labor does occur in patients with uterine irritability at a rate higher than that in the general obstetric population (18.7% vs 11.0%). Because it appears that women with uterine irritability have more resistance to conventional tocolytic therapy, this condition should prompt the physician to use more aggressive perinatal assessment.

Adult↗

PubMed1994

Risk factors for spontaneous preterm birth in a Saudi population.

Preterm birth (< 37 weeks completed gestation), the primary predictor of infant morbidity and mortality, can result from diverse biologic and sociodemographic variables. A case-control study was undertaken to determine risk factors that were significantly associated with preterm birth in our population. Pertinent data were collected by structured interviews with eligible subjects and by medical record abstraction. The study population consisted of 118 mothers of singleton, preterm, appropriate for gestational age infants (cases) and 118 mothers of singleton, term, appropriate for gestational age infants (controls). A multiple logistic regression analysis indicated that significant risk factors for preterm birth were first or second trimester vaginal bleeding during current pregnancy, a previous preterm birth, inadequate prenatal care, consanguinity, maternal body mass index of < 23, and short inter-pregnancy interval. Awareness of such risk factors is essential in planning public education programs and in considering appropriate perinatal care options for women at potentially higher risk for preterm delivery.

Adolescent↗

PubMed1995

Efficacy of oral beta-agonist maintenance therapy in preterm labor: a meta-analysis.

OBJECTIVE: To analyze the available data on the efficacy of oral beta-agonist maintenance therapy in delaying delivery and in decreasing the incidence of preterm birth and its complications. DATA SOURCES: A computer search of English-language abstracts using MEDLINE (medical subject heading terms: labor, premature and beta-adrenergic receptor agonist, therapeutic use) was supplemented with a review of the bibliographies of obstetric texts to identify randomized trials of oral beta-agonist maintenance therapy. METHODS OF STUDY SELECTION: Six trials were identified, of which four met our inclusion criteria for the meta-analysis. DATA EXTRACTION AND SYNTHESIS: Trials to be included in this meta-analysis underwent trial quality evaluation and data abstraction independently by two blinded investigators. An estimate of the odds ratio (OR) and risk difference was calculated for the dichotomous outcomes using both a random effects model and a fixed effects model. Continuous outcomes were pooled using a simple weighted average of the within-study difference in means. The pooled OR for preventing preterm delivery was 1.09 (95% confidence interval [CI] 0.60-1.99) and the OR for preventing recurrent preterm labor was 1.05 (95% CI 0.53-2.05). The pooled difference in the mean interval to delivery was -0.22 days (95% CI -2.5 to +1.99). CONCLUSIONS: The available data do not support a role for beta-agonist maintenance therapy after resolution of an acute episode of preterm labor in reducing the incidence of preterm delivery, increasing the interval to delivery, or reducing the incidence of recurrent preterm labor.

Administration, Oral↗