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PubMed2002

Cognitive and behavioral outcomes of school-aged children who were born preterm: a meta-analysis.

CONTEXT: The cognitive and behavioral outcomes of school-aged children who were born preterm have been reported extensively. Many of these studies have methodological flaws that preclude an accurate estimate of the long-term outcomes of prematurity. OBJECTIVE: To estimate the effect of preterm birth on cognition and behavior in school-aged children. DATA SOURCES: MEDLINE search (1980 to November 2001) for English-language articles, supplemented by a manual search of personal files maintained by 2 of the authors. STUDY SELECTION: We included case-control studies reporting cognitive and/or behavioral data of children who were born preterm and who were evaluated after their fifth birthday if the attrition rate was less than 30%. From the 227 reviewed studies, cognitive data from 15 studies and behavioral data from 16 studies were selected. DATA EXTRACTION: Data on population demographics, study characteristics, and cognitive and behavioral outcomes were extracted from each study, entered in a customized database, and reviewed twice to minimize error. Differences between the mean cognitive scores of cases and controls were pooled. Homogeneity across studies was formally tested using a general variance-based method and graphically using Galbraith plots. Linear meta-analysis regression models were fitted to explore the impact of birth weight and gestational age on cognitive outcomes. Study-specific relative risks (RRs) were calculated for the incidence of attention-deficit/hyperactivity disorder (ADHD) and pooled. Quality assessment of the studies was performed based on a 10-point scale. Publication bias was examined using Begg modified funnel plots and formally tested using the Egger weighted-linear regression method. DATA SYNTHESIS: Among 1556 cases and 1720 controls, controls had significantly higher cognitive scores compared with children who were born preterm (weighted mean difference, 10.9; 95% confidence interval [CI], 9.2-12.5). The mean cognitive scores of preterm-born cases and term-born controls were directly proportional to their birth weight (R(2) = 0.51; P<.001) and gestational age (R(2) = 0.49; P<.001). Age at evaluation had no significant correlation with mean difference in cognitive scores (R(2) = 0.12; P =.20). Preterm-born children showed increases in externalizing and internalizing behaviors in 81% of studies and had more than twice the RR for developing ADHD (pooled RR, 2.64; 95% CI, 1.85-3.78). No differences were noted in cognition and behaviors based on the quality of the study. CONCLUSIONS: Children who were born preterm are at risk for reduced cognitive test scores and their immaturity at birth is directly proportional to the mean cognitive scores at school age. Preterm-born children also show an increased incidence of ADHD and other behaviors.

Attention Deficit Disorder with Hyperactivity↗

PubMed2003

Neurobehavioral outcomes of school-age children born extremely low birth weight or very preterm in the 1990s.

CONTEXT: The outcome into school age of regional cohorts of children born in the 1990s with birth weights less than 1000 g (extremely low birth weight, ELBW) or earlier than 28 weeks' gestation (very preterm) is not known. OBJECTIVE: To determine the cognitive, educational, and behavioral outcome of ELBW or very preterm infants born in the 1990s compared with normal birth weight (NBW) controls. DESIGN: Regional cohort study. SETTING: Victoria, Australia. PARTICIPANTS: The ELBW or very preterm cohort was composed of 298 consecutive survivors born during 1991-1992. The NBW cohort was composed of 262 randomly selected children with birth weights of more than 2499 g. MAIN OUTCOME MEASURES: Cognitive ability, educational progress, and behavioral problems. RESULTS: The follow-up rates from birth to 8 years of age for survivors were 92.3% (275/298) for the ELBW or very preterm cohort and 85.1% (223/262) for the NBW cohort. The ELBW or very preterm children scored significantly below NBW controls on full-scale IQ (mean difference, -9.4; 95% confidence interval [CI], -12.1 to -6.7; P<.001) and indices of verbal comprehension (mean difference, -6.8; 95% CI, -9.5 to -4.2; P<.001), perceptual organization (mean difference, -9.9; 95% CI, -12.7 to -7.2; P<.001), freedom from distractibility (mean difference, -8.1; 95% CI, -10.8 to -5.5; P<.001), and processing speed (mean difference, -6.7; 95% CI, -9.4 to -4.0; P<.001). The ELBW or very preterm children performed significantly worse than the NBW cohort on tests of reading (mean difference, -6.7; 95% CI, -9.5 to -3.9; P<.001), spelling (mean difference, -5.6; 95% CI, -8.0 to -3.3; P<.001), and arithmetic (mean difference, -8.8; 95% CI, -11.3 to -6.2; P<.001). Attentional difficulties, internalizing behavior problems, and immature adaptive skills were more prevalent in the ELBW or very preterm cohort. CONCLUSION: School-aged ELBW or very preterm children born in the 1990s continue to display cognitive, educational, and behavioral impairments.

Child↗

PubMed2001

Early volume expansion versus inotrope for prevention of morbidity and mortality in very preterm infants.

BACKGROUND: Reduced perfusion of organs such as the brain, heart, kidneys and the gastrointestinal tract may lead to acute dysfunction and be associated with permanent injury. Various strategies have been used to provide cardiovascular support to preterm infants including inotropes, corticosteroids and volume expansion. OBJECTIVES: In very preterm infants, to determine the effect of early volume expansion compared to inotrope in reducing morbidity and mortality. Subgroup analysis was planned according to method of diagnosis of poor perfusion, postnatal age of treatment and type of volume expansion and inotrope used. SEARCH STRATEGY: The standard search strategy of the Cochrane Neonatal Review Group was used. SELECTION CRITERIA: All randomised trials that compared volume expansion to an inotrope in preterm infants in the first days of life were included. DATA COLLECTION AND ANALYSIS: Data were extracted independently by each author and analysed using the standard methods of the Cochrane Collaboration and its Neonatal Review Group using relative risk (RR), risk difference (RD) and weighted mean difference (WMD). MAIN RESULTS: Two small studies comparing volume expansion, using albumin, with dopamine were included. Both studies were adequately randomised, unblinded studies of albumin versus dopamine with no losses to follow up and analysed by intention to treat. Data for clinical outcomes were available from one study in hypotensive preterm infants in the first day of life. In this study, albumin had a higher failure rate for correcting hypotension (RR 5.2, 95% CI 1.3, 20.6). As 49% of these infants had already been given volume, the question of which treatment should be given first was not answered. A second study compared albumin with dopamine in preterm infants with a normal mean blood pressure at a mean age of 32 hours. Dopamine produced a significant increase in mean blood pressure when compared to infants who received albumin or no treatment, although the difference between the dopamine and albumin groups did not reach significance. Albumin and dopamine produced similar increases in left ventricular output but no significant change in cerebral blood flow. No difference was found in mortality (RR 1.5, 95% CI 0.5, 4.0) or morbidity including any P/IVH, chronic lung disease or retinopathy. There was a higher rate of grade 2-4 P/IVH of borderline statistical significance in infants who received albumin in one study (RR 1.47; 95% CI 0.96 to 2.25: RD 0.27, 95% CI 0.00 to 0.54). No data were available for neurodevelopmental outcomes. REVIEWER'S CONCLUSIONS: Dopamine was more successful than albumin at correcting low blood pressure in hypotensive preterm infants, many of whom had already received volume. Neither intervention has been shown to be superior at improving blood flow, or in improving mortality and morbidity in preterm infants. The trials do not allow any firm conclusions to be made as to whether or when volume or dopamine should be used in preterm infants.

Albumins↗

PubMed2002

Hydration for treatment of preterm labour.

BACKGROUND: Hydration has been proposed as a treatment for women with preterm labour. Theoretically, hydration may reduce uterine contractility by increasing uterine blood flow and by decreasing pituitary secretion of antidiuretic hormone and oxytocin. OBJECTIVES: To evaluate the effectiveness of intravenous or oral hydration to avoid preterm birth and its consequences in women with preterm labour. SEARCH STRATEGY: The Cochrane Pregnancy and Childbirth Group trials register (January 2002), the Cochrane Controlled Trials register (The Cochrane Library, Issue 1, 2002) and bibliographies of relevant papers were searched. SELECTION CRITERIA: Randomised controlled trials, including women with a viable pregnancy less than 37 completed weeks' gestation and presenting with preterm labour, comparing intravenous or oral hydration with no treatment. The intervention might or might not be associated with bed rest. Studies comparing tocolytic drugs with intravenous fluids used in the control group as a placebo were not included in this review. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed the reports, to determine if the study met the inclusion criteria and to evaluate the methodological quality. Data were extracted independently by two of the reviewers. The results were expressed as relative risks (RR) for dichotomous outcomes and weighted mean difference for continuous outcomes. MAIN RESULTS: Two studies, including a total of 228 women with preterm labour and intact membranes, compared intravenous hydration with bed rest alone. Risk of preterm delivery, before 37 weeks (relative risk (RR): 1.09; 95% confidence interval (CI): 0.71-1.68), before 34 weeks (RR: 0.72; 95% CI: 0.20-2.56) or before 32 weeks (RR: 0.76; 95% CI: 0.29-1.97), was similar between groups. Admission to neonatal intensive care unit occurred with similar frequency in both groups (RR: 0.99; 95% CI: 0.46-2.16). Cost of treatment was slightly higher (US$39) in the hydration group. This difference was not statistically significant and only includes hospital costs during a visit of less than 24 hours. No studies evaluated oral hydration. REVIEWER'S CONCLUSIONS: The data are too few to support the use of hydration as a specific treatment for women presenting with preterm labour. The two small studies available do not show any advantage of hydration compared to bed rest alone. Intravenous hydration does not seem to be beneficial, even during the period of evaluation soon after admission, in women with preterm labour. Women with evidence of dehydration may, however, benefit from the intervention.

Female↗

PubMed2006

Antenatal corticosteroids for accelerating fetal lung maturation for women at risk of preterm birth.

BACKGROUND: Respiratory distress syndrome (RDS) is a serious complication of preterm birth and the primary cause of early neonatal mortality and disability. OBJECTIVES: To assess the effects on fetal and neonatal morbidity and mortality, on maternal mortality and morbidity, and on the child in later life of administering corticosteroids to the mother before anticipated preterm birth. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group Trials Register (30 October 2005). SELECTION CRITERIA: Randomised controlled comparisons of antenatal corticosteroid administration (betamethasone, dexamethasone, or hydrocortisone) with placebo or with no treatment given to women with a singleton or multiple pregnancy, expected to deliver preterm as a result of either spontaneous preterm labour, preterm prelabour rupture of the membranes or elective preterm delivery. DATA COLLECTION AND ANALYSIS: Two review authors assessed trial quality and extracted data independently. MAIN RESULTS: Twenty-one studies (3885 women and 4269 infants) are included. Treatment with antenatal corticosteroids does not increase risk to the mother of death, chorioamnionitis or puerperal sepsis. Treatment with antenatal corticosteroids is associated with an overall reduction in neonatal death (relative risk (RR) 0.69, 95% confidence interval (CI) 0.58 to 0.81, 18 studies, 3956 infants), RDS (RR 0.66, 95% CI 0.59 to 0.73, 21 studies, 4038 infants), cerebroventricular haemorrhage (RR 0.54, 95% CI 0.43 to 0.69, 13 studies, 2872 infants), necrotising enterocolitis (RR 0.46, 95% CI 0.29 to 0.74, eight studies, 1675 infants), respiratory support, intensive care admissions (RR 0.80, 95% CI 0.65 to 0.99, two studies, 277 infants) and systemic infections in the first 48 hours of life (RR 0.56, 95% CI 0.38 to 0.85, five studies, 1319 infants). Antenatal corticosteroid use is effective in women with premature rupture of membranes and pregnancy related hypertension syndromes. AUTHORS' CONCLUSIONS: The evidence from this new review supports the continued use of a single course of antenatal corticosteroids to accelerate fetal lung maturation in women at risk of preterm birth. A single course of antenatal corticosteroids should be considered routine for preterm delivery with few exceptions. Further information is required concerning optimal dose to delivery interval, optimal corticosteroid to use, effects in multiple pregnancies, and to confirm the long-term effects into adulthood.

Adrenal Cortex Hormones↗

PubMed2005

Lactase treated feeds to promote growth and feeding tolerance in preterm infants.

BACKGROUND: Successful transition from parenteral nutrition to full enteral feedings during the immediate neonatal period is associated with improved growth in preterm infants. Lactase is the last of the major intestinal disaccharidases to develop in preterm infants. Because of inadequate lactase activity, preterm infants are unable to digest lactose. Lactase preparations could potentially be used to hydrolyze lactose in formulas and breast milk to minimize lactose malabsorption in preterm infants. OBJECTIVES: To assess the effectiveness and safety of the addition of lactase to milk compared to placebo or no intervention for the promotion of growth and feeding tolerance in preterm infants. PRIMARY OUTCOMES: Weight gain expressed as g/kg/day, growth expressed as weight, length and head circumference percentile for gestational age, assessed at birth and at 40 weeks post-menstrual age, days to achieve full enteral feeds. SECONDARY OUTCOMES: Several common outcomes associated with preterm birth, and adverse effects. SEARCH STRATEGY: Electronic and manual searches were conducted in January 2005 of Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2004), MEDLINE (1966-Jan 2005), EMBASE (1980-Jan 2005) and CINAHL (1982-Jan 2005), personal files, bibliographies of identified trials and abstracts by the Pediatric Academic Societies' and the European Society of Pediatric Research Meetings published in Pediatric Research. SELECTION CRITERIA: Types of studies: Randomized or quasi-randomized controlled trials. PARTICIPANTS: Preterm infants < 37 weeks gestational age. INTERVENTION: Addition of lactase to milk versus placebo or no intervention. DATA COLLECTION AND ANALYSIS: The standard methods of the Cochrane Neonatal Review Group were followed independently by the reviewers to assess study quality and report outcomes. Treatment effects, calculated using RevMan 4.2, included relative risk (RR), risk difference (RD) and mean difference (MD), all with 95% confidence intervals (CI). A fixed effect model was used for meta-analyses. Heterogeneity tests were not performed as only one study was identified. MAIN RESULTS: One study enrolling 130 infants of 26 - 34 weeks postconceptual age (mean postnatal age at entry 11 days) was identified and no identified study was excluded. The study was a double blind randomized controlled trial of high quality. Lactase treated feeds were initiated when enteral feedings provided > 75% of daily intake. None of the primary outcomes outlined in the protocol for this review and only one of the secondary outcomes, necrotizing enterocolitis (NEC), were reported on. The RR for NEC was 0.32 (95% CI 0.32 (0.01, 7.79); the RD was -0.02 (95% CI -0.06, 0.03) (a reduction which was not statistically significant). There was a statistically significant increase in weight gain at study day 10 in the lactase treated feeds group but not at any other time points. Overall, there ws not a statistically significant effect on weight gain. No adverse effects were noted. AUTHORS' CONCLUSIONS: The only randomized trial to date provides no evidence of significant benefit to preterm infants from adding lactase to their feeds. Further research regarding effectiveness and safety are required before practice recommendations can be made. Randomized controlled trials comparing lactase vs placebo treated feeds and enrolling infants when enteral feeds are introduced are recommended. The primary and secondary outcomes for effectiveness and safety should include those identified in this review.

Enteral Nutrition↗

PubMed2006

Iodine supplementation for the prevention of mortality and adverse neurodevelopmental outcomes in preterm infants.

BACKGROUND: Parenteral nutrition solutions, formula milks, and human breast milk contain insufficient iodine to meet recommended intakes for preterm infants. Iodine deficiency may exacerbate transient hypothyroxinaemia in preterm infants and this may be associated with adverse respiratory or neurological outcomes. OBJECTIVES: To assess the evidence from randomised controlled trials that dietary supplementation with iodine reduces mortality and morbidity in preterm infants. SEARCH STRATEGY: We used the standard search strategy of the Cochrane Neonatal Review Group. This included searches of the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library, Issue 4, 2005), MEDLINE (1966 - November 2005), EMBASE (1980 - November 2005), CINAHL (1982 - November 2005), conference proceedings, and previous reviews. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials that compared a policy of supplementing enteral or parenteral feeds with iodine (more than 30 micrograms per kilogram per day) versus placebo or no supplementation in preterm infants. DATA COLLECTION AND ANALYSIS: The standard methods of the Cochrane Neonatal Review Group, with separate evaluation of trial quality and data extraction by two reviewers, and synthesis of data using relative risk, risk difference and weighted mean difference. The primary outcomes for this review were neonatal mortality, death before hospital discharge, and longer term neurodevelopmental outcomes including severe neurodevelopmental disability. MAIN RESULTS: We found only one randomised controlled trial (N = 121) that fulfilled the review eligibility criteria (Rogahn 2000). The participants were infants born before 33 weeks' gestation (but most were of birth weight greater than 1000 grams). The primary aim of this trial was to assess the effect of iodine supplementation on thyroid function. The investigators did not detect any statistically significant effects on the plasma levels of thyroxine (free and total), triiodothyronine, or thyrotrophin in preterm infants (measured up to 40 weeks' post-conceptional age). Only one infant died and the trial was therefore underpowered to detect an effect on mortality. The trial did not assess the effect of the intervention on neurodevelopmental morbidity. There was not a statistically significant difference in the incidence of chronic lung disease. AUTHORS' CONCLUSIONS: There are insufficient data at present to determine whether providing preterm infants with supplemental iodine (to match fetal accretion rates) prevents morbidity and mortality in preterm infants. Future randomised controlled trials of iodine supplementation should focus on extremely preterm and extremely low birth weight infants, the group at greatest risk of transient hypothyroxinaemia. These trials should aim to assess the effect of iodine supplementation on clinically important outcomes including respiratory morbidity and longer term neurodevelopment.

Developmental Disabilities↗

PubMed2002

Cerebral palsy in very preterm infants: new epidemiological insights.

The focus of this review is on new insights from recent epidemiological research on cerebral palsy in preterm infants. These include: 1) a better understanding of issues related to diagnosis and classification; 2) new information about the brain abnormalities underlying cerebral palsy in preterm infants; and 3) a better understanding of biological mechanisms that may underlie previously described epidemiological associations. Ongoing efforts to improve the diagnosis and classification of cerebral palsy have been enhanced by findings from serial examinations of cohorts of very preterm infants. Cranial ultrasonography through the anterior fontanelle of very preterm infants has provided information about grossly evident brain damage, found in about one-half of preterm infants who develop cerebral palsy. Insights into the pathophysiologic basis for certain epidemiologic associations have come from studies of experimental brain damage in animals and clinical studies of neurologic disorders in adults. Much of the current epidemiological research into the causes of cerebral palsy in preterm infants has focused on two potential mechanisms of brain damage. One mechanism involves insufficient cerebral perfusion; the other, cytokine-mediated damage, potentially triggered by events such as maternal infection (e.g., intrauterine or periodontal infection), neonatal infection (e.g., sepsis and necrotizing enterocolitis), and neonatal oxygen- or ventilator-induced lung injury. In addition to the preterm infant's increased exposure to such damaging factors, the high frequency of cerebral palsy in these infants might be due, in part, to insufficient levels of developmentally regulated protective substances, such as thyroid hormone and glucocorticoids. Models of causation currently are being investigated using recently developed methods for quantifying, with small quantities of blood, biomolecules that are suspected to either promote or protect against brain damage in the neonate. Clinical investigations now under way can be expected to identify strategies to be tested in clinical trials that could lower the risk of cerebral palsy in very preterm infants.

Brain↗

PubMed2001

Functional residual capacity and passive compliance measurements after antenatal steroid therapy in preterm infants.

Studies in preterm animal models have shown that antenatal corticosteroids enhance lung maturation by improving a variety of physiologic variables, including lung volumes. Changes in lung volume of preterm infants treated with a full course of antenatal steroids have not been investigated. We hypothesized that a full course of antenatal steroids would significantly increase functional residual capacity (FRC) in treated vs. untreated preterm infants. The objective of our study was to compare FRC and respiratory mechanics in steroid treated vs. untreated preterm infants. FRC and passive respiratory mechanics were prospectively studied within 36 hr of life in 20 infants (25-34 weeks of gestation) who had received a full course of antenatal steroids and in 20 matched untreated preterm infants. FRC was measured with the nitrogen washout method, and respiratory mechanics with the single-breath occlusion technique. Preterm infants who received steroids (n = 20; mean birth weight = 1,230 g; gestational age = 28.8 weeks) had a significantly higher FRC (29.5 vs. 19.3 mL/kg; P < 0.001) than untreated infants (n = 20; birth weight = 1,202 g; gestational age = 28.5 weeks). Passive respiratory system compliance was also increased in treated vs. untreated infants (P < 0.05). In conclusion, FRC and passive respiratory system compliance were significantly improved in preterm infants (25-34 weeks gestation) treated with a full course of antenatal steroids, compared to matched untreated infants. Although this study was not randomized, it confirms that antenatal steroids have important effects on pulmonary function that may contribute to a decreased risk of respiratory distress syndrome in treated preterm infants.

Female↗

PubMed2006

Respiratory function at age 8-9 years in extremely low birthweight/very preterm children born in Victoria in 1991-1992.

Our aim was to determine respiratory function at 8 years of age in extremely low birth weight (ELBW; birth weight, < 1,000 g)/very preterm (< 28 weeks of gestation) children born in the 1990s compared with normal birth weight (NBW; birth weight, >2,499 g) controls. The ELBW/very preterm subjects comprised 298 consecutive survivors with either birth weight < 1,000 g or gestational age < 28 weeks born in the state of Victoria during 1991-1992. Controls comprised 262 randomly selected NBW survivors. Respiratory function was measured on 81% (240/298) of the ELBW/very preterm children and 79% (208/262) of the NBW controls. Respiratory function variables reflecting airflow were substantially diminished in ELBW/very preterm children compared with NBW controls. Moreover, the proportions with clinically important reductions in airflow were higher in the ELBW/very preterm group (e.g., forced expired volume in 1 sec, < 75%; ELBW/very preterm, 19.7%; NBW, 2.4%; P < 0.0001). Within the ELBW/very preterm group, children who had bronchopulmonary dysplasia (BPD) in the newborn period and those who had later asthma had significantly reduced respiratory function in variables reflecting airflow. In conclusion, the abnormalities in respiratory function in ELBW/very preterm children compared with NBW subjects described in the presurfactant era persisted in the 1990s, especially in those who had BPD in the newborn period.

Asthma↗

PubMed2004

Prediction of preterm delivery in twin pregnancy: a prospective, observational study of cervical length and fetal fibronectin testing.

OBJECTIVE: To evaluate prospectively cervical length measurements and fetal fibronectin detection as predictors of spontaneous preterm delivery in an unselected population of twin pregnancies. METHODS: Transvaginal ultrasound assessments of cervical length were performed serially at 18, 24, 28 and 32 weeks' gestation. Receiver-operating characteristic curves were generated at each time point to determine the optimal cut-off for cervical length and rate of change in cervical length in the prediction of preterm delivery (< 35 weeks). A bedside assay for the detection of fetal fibronectin in the maternal vaginal secretions was performed prior to cervical length measurements from 24 weeks. Likelihood ratios (LRs) were used to assess the performance of each test. RESULTS: The spontaneous preterm delivery rate was 16.5% in 91 studied twin pregnancies. A cervical length </= 25 mm at 18 weeks (LR+ 9.7, sensitivity 14.3%) and </= 22 mm at 24 weeks (LR+ 9.6, sensitivity 28.6%) were the best predictors of preterm delivery. A shortening of cervical length >/= 2.5 mm per week between 18 and 28 weeks' gestation also predicted preterm delivery (LR+ 10.8, sensitivity 16.7%). There was no relationship between the detection of fetal fibronectin and preterm delivery. CONCLUSIONS: This study confirms the value of transvaginal ultrasound assessment of cervical length as a predictor of preterm delivery in twin pregnancies. However, the poor sensitivity of this test makes it unsuitable as a single predictor of preterm delivery. Fetal fibronectin testing does not identify twin pregnancies destined to deliver prematurely.

Adult↗

PubMed2004

Second-trimester uterine artery Doppler and spontaneous preterm delivery.

OBJECTIVE: To assess the relationship between second-trimester uterine artery (UtA) Doppler measurements and spontaneous preterm delivery. METHODS: This was a retrospective analysis of UtA Doppler findings at 18-23 weeks' gestation in 234 singleton pregnancies with spontaneous preterm labor and 5472 pregnancies delivered at term. Cases with fetal chromosomal or structural abnormalities, pre-eclampsia, small-for-gestational-age (SGA) fetuses, concurrent maternal disease, cervical cerclage or history of cone biopsy were excluded. RESULTS: UtA mean resistance index (RI) and number of protodiastolic notches were not significantly different in the spontaneous preterm labor group compared to the normal group. The 62 preterm deliveries not preceded by spontaneous preterm premature rupture of membranes (PPROM) showed a significantly higher RI and prevalence of bilateral notches than cases of preterm deliveries preceded by PPROM (n = 172). However, this difference was not confirmed in a logistic regression model. CONCLUSION: Despite pathological evidence suggesting that defective placentation is associated with spontaneous preterm delivery, second-trimester UtA resistance, as assessed by Doppler ultrasound investigation, is not different in pregnancies subsequently complicated by preterm labor compared to pregnancies delivered at term.

Adult↗

PubMed2005

Kidney development in the first year of life in small-for-gestational-age preterm infants.

BACKGROUND: Small-for-gestational-age (SGA) infants have been reported to have a significantly reduced number of nephrons that could be a risk factor for development of hypertension later in life. OBJECTIVE: To evaluate kidney size prospectively in relation to other anthropometric parameters during the first year of life in SGA babies. MATERIALS AND METHODS: The babies in the study were 31-36 weeks' gestational age (GA) at birth and were matched with control preterm infants of similar GA, but appropriate for gestational age (AGA). The SGA infants were further classified as symmetrical and asymmetrical according to the anthropometric parameters. RESULTS: The total number of measurements in symmetrical SGA preterm infants was 324, in asymmetrical SGA preterm infants 295, and in AGA infants 536. In symmetrical SGA preterm infants (31-36 weeks' GA) mean kidney length (+/- SD) of 56+/-4 mm was significantly different from the controls (58.9+/-4.6 mm) up to 6 months' chronological age (P < 0.05). In the asymmetrical SGA preterm infants, mean kidney length (45.3+/-4.0 mm) was significantly different from the controls (48.2+/-4.4 mm) up to 40 weeks' corrected age. At 1 year chronological age, all preterm infants (symmetrical and asymmetrical SGA and AGA) had similar mean kidney length (61.6+/-4.6, 62.8+/-4.3, and 62.3+/-4.0 mm, respectively). The ratio of kidney length to crown-to-heel length was similar in all preterm groups. CONCLUSIONS: Kidney length in preterm SGA infants (symmetrical and asymmetrical) follows closely the other auxological parameters during the first year of life.

Birth Weight↗

PubMed1999

Hepatitis B vaccination in preterm infants.

UNLABELLED: Preterm infants, especially those with very low birth weight, are at risk of hepatitis B virus infection. They often require invasive diagnostic methods in their first weeks of life, intensive treatment and long-term hospitalisation. Therefore, hepatitis B vaccination is particularly justified in these patients. Our aim was to determine the reaction of preterm children to hepatitis B vaccination. The study comprised 64 preterm children whose birth weight ranged from 700 g to 2460 g (mean 1776.6 g +/- 480.4 g) and whose gestational age was between 25 and 36 weeks. A 10 microg dose of the recombinant vaccine Engerix-B (SmithKline Beecham) was given at intervals of 0, 1, 2 and 12 months. In 49.2% of the children vaccination was administered on the 1st day of life, and in the remaining cases between the 2nd and 119th days post delivery. One month after vaccination completion the levels of anti-hepatitis B surface antigen (HBs) antibodies were evaluated. In 98.4% of the vaccinated preterm infants the level of antibodies was > 10 mIU/ml. Mean level of anti-HBs antibodies in the group of children with birth weight < or = 2000 g was 2431.4 mIU/ml, while in those with birth weight >2000 g it was 4803.9 mIU/ml. In children with a birth weight < or = 1000 g, the mean level of anti-HBs antibodies was significantly lower than in those with birth weight >2000 g. The level of anti-HBs antibodies in children who started vaccination > 1 st day of life was significantly lower in preterm children with a birth weight < or = 2000 g than in those with a birth weight >2000 g. Although vaccination was started on the 1st day of his life, one child with birth weight of 2300 g developed a hepatitis B virus infection. One child did not respond to vaccination (anti-HBs < 10 mIU/ml) and in three cases the response was very poor (11 100 mIU/ml). These patients were given a supplementary booster double dose of Engerix B (20 microg). After 1 month the level of anti-HBs antibodies was evaluated again and high values of 657 mIU/ml to 14520 mIU/ml were observed. In the group of children with a birth weight < or = 1000 g the response to vaccination was weaker as compared to children with a birth weight >2000 g (P < 0.05). In systematic mass vaccination programmes, monitoring of antibody levels is not recommended unless the patient is at risk. However, in extremely preterm infants (< 1000 g at birth), especially after very serious infections, monitoring the level of anti-HBs antibodies after complete immunisation should be considered. In preterm infants who show very low postvaccination levels of anti-HBs antibodies, stimulation with an additional double booster dose of vaccine gives positive results. CONCLUSION: The majority of preterm infants (98.4%) responded well to hepatitis B vaccination given at intervals of 0, 1, 2 and 12 months and developed a protective level of antibodies. The level of anti-hepatitis B surface antigen antibodies in children with a birth weight >2000 g was higher than in those with a birth weight < or = 1000 g.

Female↗

PubMed1999

Bone mineralisation in ex-preterm infants aged 8 years.

UNLABELLED: In preterm infants, in whom perinatal mineralisation deficits are common, there is little information on long-term bone mineralisation. Using a Hologic QDR 1000 dual energy X-ray absorptiometer, bone mineral content and density (BMC and BMD) were measured in lumbar, spine, forearm and hip in 46 ex- preterm infants <32 weeks gestation together with controls at 8 years of age. Height and weight were recorded, as was history of bone fracture. Preterm infants were shorter by 4.9 cm (95% CI, 2.4 7.3) and lighter by 2.6 kg (95% CI, 0.7 4.4). BMC for all sites measured was significantly lower in the preterm group, but did not remain so when adjusted for height and weight. BMD was significantly reduced in the hip of the preterm group. Prolonged ventilation was associated with the lowest BMC and duration of preterm formula feeding correlated with higher BMC. Accidental fractures were less common in the preterm group. CONCLUSION: Ex preterm infants have significant reduction in bone mineral mass commensurate with their reduced growth and reduced bone mineral density in their hips.

Absorptiometry, Photon↗

PubMedDate not supplied

Histomorphometric analysis of postnatal glomerulogenesis in extremely preterm infants.

Until now oligonephropathy to indicate "too few nephrons" has been associated with intrauterine growth restriction and experimentally induced abnormalities of renal development. The purpose of this study was to determine whether there is evidence of abnormal postnatal glomerulogenesis in extremely low birth weight preterm infants. Renal autopsy tissue was studied by computer-assisted morphometry from 56 extremely premature infants (birth weight < or = 1000 g) and 10 fullterm infants as controls. Preterm infants were divided into two groups (short survival < or = 40 days vs. long survival > or = 40 days). Each group was subdivided into those with renal failure (RF) and those with normal renal function. Forty-two of 56 preterm infants (75%) were adequate for gestational age. Glomerulogenesis as measured by radial glomerular counts (RGC) was markedly decreased in all preterm infants as compared to term controls and correlated significantly with gestational age (r = 0.87; P < 0.001). Active glomerulogenesis with "basophilic S-shaped bodies" was absent in longer surviving preterm and all term infants. RGC of preterm infants surviving > or =40 days with RF were significantly less than RGC of those with long survival and no RF (P < 0.001). Only this latter group demonstrated increased glomerular size as measured by mesangial tuft area and Bowman's capsule area compared to all other groups (P < 0.001). The kidney continues to form postnatally in preterm neonates, but glomerulogenesis ceases after 40 days. Moreover, it is further inhibited by RF. Compensatory mechanisms in longer surviving preterm infants include glomerular hypertrophy and mesangial proliferation that could lead to hyperfiltration.

Female↗

PubMed1984

Preterm delivery is not predicted by serial plasma estradiol or progesterone concentration measurements.

Previous studies suggest that plasma estradiol-17 beta and progesterone concentration values differ between patients who deliver before term and those who deliver at term. To determine if these values would aid in preterm delivery risk prediction, we measured plasma estradiol-17 beta and progesterone concentrations serially in 90 patients at high risk for preterm delivery. Measurements from 17 patients who developed documented preterm labor and/or were delivered before term were compared to the tenth and ninetieth percentiles of 42 patients who were delivered at term. The sensitivity of these measurements to predict preterm delivery was very low. Also, the mean plasma estradiol-17 beta and progesterone concentrations in patients with preterm labor who had term deliveries and in patients with preterm labor that progressed to preterm delivery were not different from each other or from patients delivering at term. No change in plasma estradiol-17 beta or progesterone concentration was noted preceding labor. We conclude that serial measurements of plasma estradiol-17 beta and progesterone concentrations do not improve preterm delivery risk prediction.

Adolescent↗

PubMed1985

Can preterm deliveries be prevented?

Our hospital serves poor, inner-city women who have a 17% preterm delivery rate. Middle-class women in San Francisco at high risk for preterm delivery have benefited from an antepartum program which emphasized patient education and close follow-up. Using a controlled, randomized design, we are investigating the impact of similar interventions. Patients determined to be at high risk before 18 weeks' gestation on the basis of the Creasy system are randomly assigned to the Preterm Labor Prevention Clinic or serve as high-risk controls. Sixty-four women assigned to the Preterm Labor Prevention Clinic and 68 high-risk control women have been delivered of their infants. No significant differences were noted for the percentages of preterm infants, mean gestational age, or birth weight. Preterm rupture of the membranes accounted for 40% of preterm deliveries in all high-risk patients. Thirty percent of preterm births were indicated for maternal or fetal reasons. The remaining 30% represented failure of tocolytic therapy.

Birth Weight↗