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PubMed2005

The influence of gestational age and birth weight in the clinical assessment of the muscle tone of healthy term and preterm newborns.

OBJECTIVE: To evaluate the influence of gestational age (GA) and birth weight (BW) in the clinical assessment of the muscle tone of healthy term and preterm newborns. METHOD: Cross sectional study. The muscle tone of healthy 42 preterm and 47 term newborns was quantified and measured with a goniometer (an instrument for measuring angles) respectively between 7th-14th day of life and 24-48 hours of life. Newborns were grouped according to GA and BW and evaluated at fixed time intervals by one examiner. Preterm newborns were matched to term at 40 weeks postconceptional age (PCA). RESULTS: The evolution of muscle tone in the preterm occurred gradually, following PCA, independent of birth weight. Preterm newborns had lower scores in all muscle tone indicators when compared to term at the first assessment. Differences were observed among preterm small for GA and adequate to GA for the indicator heel to ear (p<0.001). When compared at 40 weeks PCA, except for posture, all other indicators were significantly different (p< 0.001) among groups. CONCLUSION: Prematurity and intrauterine malnutrition are influential factors in some indicators of the newborn muscle tone state. Muscle tone assessment of preterm infants does not seem to be influenced by birth weight, however evolution is clearly related to postconceptional age. When we compared term newborns AGA and SGA it seems to have a clear influence of the birth weight on some indicators of the muscle tone. The use of devices such as the goniometer allows the performance of a more objective assessment of muscle tone and helps to quantify findings.

Analysis of Variance↗

PubMed2004

Contrast sensitivity threshold measured by sweep-visual evoked potential in term and preterm infants at 3 and 10 months of age.

Although healthy preterm infants frequently seem to be more attentive to visual stimuli and to fix on them longer than full-term infants, no difference in visual acuity has been reported compared to term infants. We evaluated the contrast sensitivity (CS) function of term (N = 5) and healthy preterm (N = 11) infants at 3 and 10 months of life using sweep-visual evoked potentials. Two spatial frequencies were studied: low (0.2 cycles per degrees, cpd) and medium (4.0 cpd). The mean contrast sensitivity (expressed in percentage of contrast) of the preterm infants at 3 months was 55.4 for the low spatial frequency (0.2 cpd) and 43.4 for the medium spatial frequency (4.0 cpd). At 10 months the low spatial CS was 52.7 and the medium spatial CS was 9.9. The results for the term infants at 3 months were 55.1 for the low spatial frequency and 34.5 for the medium spatial frequency. At 10 months the equivalent values were 54.3 and 14.4, respectively. No difference was found using the Mann-Whitney rank sum T-test between term and preterm infants for the low frequency at 3 or 10 months or for the medium spatial frequency at 3 or 10 months. The development of CS for the medium spatial frequency was equally fast for term and preterm infants. As also observed for visual acuity, CS was equivalent among term and preterm infants, suggesting that visual experience does not modify the development of the primary visual pathway. An earlier development of synapses in higher cortical visual areas of preterm infants could explain the better use of visual information observed behaviorally in these infants.

Contrast Sensitivity↗

PubMed2006

Tuberculin skin reactivity after neonatal BCG vaccination in preterm infants in Minas Gerais, Brazil, 2001-2002.

OBJECTIVES: The efficacy of BCG vaccination in preterm babies is unknown, and available data on conversion rates to tuberculin in this age group are scarce and controversial. This study assessed the tuberculin response in preterm infants after BCG vaccination. METHODS: This randomized cohort study was carried out at the Neonatal Department, University Hospital, Federal University of Minas Gerais in Brazil during 2001 and 2002. The BCG vaccine was administered at birth to 65 full-term (control) and 40 preterm newborns. All of them were tested with 5 tuberculin units of purified protein derivative-S approximately 3 months after vaccination. RESULTS: A typical BCG scar was verified in 96.9% of the control group and in 90.0% of the preterm infants (P = 0.19). Indurations > 5 mm in diameter were recorded in 87.7% of the full-term and 67.5% of the preterm infants (P = 0.02). Indurations > 10 mm were recorded in 70.8% of the full-term and 42.5% of the preterm infants (P = 0.007). For indurations > 5 mm the upper and the lower limits of the 95% confidence interval for the difference between proportions were 8.5% to 31.8%, and for indurations > 10 mm these limits were 18.0% to 38.4%. No adverse reactions were observed in the study population. CONCLUSION: BCG vaccination could be recommended for preterm infants upon discharge from the neonatal unit to reduce morbidity and mortality in infants at risk for tuberculous infection, and to increase BCG vaccination coverage rates, especially in countries with high prevalence rates of tuberculosis.

BCG Vaccine↗

PubMed2000

The effect of intermittent umbilical cord occlusion on insulin-like growth factors and their binding proteins in preterm and near-term ovine fetuses.

Intermittent umbilical cord compression with resultant fetal hypoxia can have a negative impact on fetal growth and development. Insulin-like growth factors (IGFs) and their binding proteins (IGFBPs) are the most important regulators of fetal growth. In preterm (107-108 days of gestation) and near-term (128-131 days of gestation) ovine fetuses, we have determined the effect of intermittent umbilical cord occlusion (UCO) over a period of 4 days on the profile and expression of IGFs and IGFBPs. In experimental group animals (preterm n=7; near term n=7) UCOs were carried out by complete inflation of an occluder cuff (duration 90 s) every 30 min for 3-5 h each day, while control fetuses (preterm n=7; near term n=7) received no UCOs. Ewes were euthanized at the end of day 4, and fetal heart, lung, kidney, liver, skeletal muscle and placenta were collected. During UCOs, PO(2! ) fell (by approximately 13 mmHg), pH fell (by approximately 0.05) and PCO(2) increased (by approximately 7 mmHg), and changed to a similar extent in both preterm and near-term groups. In both preterm and near-term groups, there was no difference in fetal body or organ weight between UCO and control fetuses. No significant changes were observed in plasma IGF-I and -II concentrations or IGFBP-1, -2, -3 or -4 levels throughout the 4-day study at either gestational age. In the preterm group UCO fetuses, IGF-II mRNA (1.2-6.0 kb) levels were lower in fetal lung (33%, P<0.05), heart (54%, P<0.01) and skeletal muscle (29%, P<0.05), but there were no differences in IGF-I mRNA levels (7.3 kb); IGFBP-2 mRNA (1.5 kb) levels were lower in the right lobe of the liver (42%, P<0.05) and kidney (22%, P<0.01), but hig! her in the heart (72%, P<0.01), while IGFBP-4 (2.4 kb) levels were lower in skeletal muscle (21%, P<0.01). In the near-term group UCO fetuses, IGFBP-2 mRNA levels were greater in the placenta (39%, P<0.05). Thus, intermittent UCO as studied has a greater effect on the expression of genes encoding certain peptides of the fetal IGF system in selected tissues in preterm fetuses than that in near-term fetuses. Altered IGFBP-2 mRNA levels with reduced IGF-II mRNA levels in selected tissues may mediate changes in growth and/or differentiation that might become apparent if the length of the UCO study were extended.

Analysis of Variance↗

PubMed2006

Maternal obesity in early pregnancy and risk of spontaneous and elective preterm deliveries: a retrospective cohort study.

OBJECTIVES: We sought to determine the association between maternal body mass index and risk of preterm delivery. METHODS: We assessed 187,290 women in Scotland and estimated adjusted odds ratios for spontaneous and elective preterm deliveries among overweight, obese, and morbidly obese women relative to normal-weight women. RESULTS: Among nulliparous women, the risk of requiring an elective preterm delivery increased with increasing BMI, whereas the risk of spontaneous preterm labor decreased. Morbidly obese nulliparous women were at increased risk of all-cause preterm deliveries, neonatal death, and delivery of an infant weighing less than 1000 g who survived to 1 year of age (a proxy for severe long-term disability). By contrast, obesity and elective preterm delivery were only weakly associated among multiparous women. CONCLUSIONS: Obese nulliparous women are at increased risk of elective preterm deliveries. This in turn leads to an increased risk of perinatal mortality and is likely to lead to increased risks of long-term disability among surviving offspring.

Adult↗

PubMed1992

Time course of trough serum gentamicin concentrations in preterm and term neonates.

Trough serum concentrations (Cmin) of gentamicin were followed during up to 96h of treatment in 44 neonates (17 preterm and 27 term), treated with intramuscular gentamicin 2.5 +/- 0.3 mg/kg (mean +/- SD) twice daily, a dosage that was not changed during the follow-up period. Relationships with patients' gestational age, postnatal age, postconceptional age and bodyweight were analysed to identify circumstances in which gentamicin should be monitored. Gentamicin Cmin values after 24h correlated better with neonate's postconceptional age (r = -0.42) or gestational age (r = -0.37) than with postnatal age or bodyweight. Correlations with postconceptional age and gestational age improved after 96h (r = -0.71 and r = -0.67, respectively). From 24 to 96h Cmin increased from 1.5 to 2 mg/L (p < 0.001) in the preterm neonates and from 1.5 to 2.5 mg/L (p < 0.01) in those preterm neonates < or = 32 weeks of gestational age, while differences between neonates < or = 3 days and > 3 days of postnatal age were nonsignificant. The Cmin at 24h was potentially toxic (> 2 mg/L) in 9% of the neonates (12% of preterm and 7% of term neonates). At 96h, the percentage of neonates with toxic Cmin values increased to 25% (65% of all preterm neonates and 100% of preterm neonates < or = 32 weeks of gestational age), whereas in term neonates it decreased to 0%. In conclusion, in preterm neonates < or = 32 weeks of gestational age a dosage of 2.5 mg/kg every 24h should be used, and gentamicin concentrations should be monitored. However, in term neonates > 7 days of postnatal age a dosage of 3.5 mg/kg twice daily should be recommended.

Analysis of Variance↗

PubMed2003

Preterm labour: an overview of current and emerging therapeutics.

Preterm labour is a major cause of perinatal mortality and morbidity. However, during the past 40 years of clinical studies and despite the use of multiple therapeutic agents, the rate of preterm birth has not drastically declined. In 1991, it was estimated that in the US approximately 116,000 women admitted with acute episodes of preterm labour were treated each year with ritodrine, which is the first drug approved by the US FDA and still remains the standard therapy for treating preterm labour. Ritodrine (Yutopar( trade mark )) stimulates the beta(2)-adrenergic receptor throughout the body, causing an inhibitory action in different tissues that, among other side effects, also leads to an attenuation of uterine contractility. More recently, a new therapeutic agent, atosiban (Tractocile( trade mark )), a peptidic oxytocin receptor antagonist, has been introduced to the market. However, the use of the various pharmacological agents to treat preterm labour remains restricted, due to lack of uterine selectivity, low efficacy and potentially serious side effects for the mother or the foetus. Therefore, there is an urgent need to develop drugs with myometrial selectivity that would allow long-lasting inhibition of labour and prolong pregnancy up to a stage when good foetal maturation raises the chances of survival. One of the major obstacles hampering the development of new therapeutic agents is the marked inter-species difference in terms of preterm labour physiology, which complicates the preclinical evaluation of new candidate molecules in animal models of disease. In this review, the authors will provide a comprehensive update of past, current and new approaches for the management of preterm labour, including beta(2)-adrenergic agonists, calcium channel blockers, oxytocin antagonists, prostaglandin antagonists and other potential therapeutics. For each of the therapies used today, the review will cover the mechanism of action, benefit and adverse effects, and discuss the promise and potential benefits of new emerging therapeutic agents.

Adrenergic beta-Agonists↗

PubMed2006

Transient periventricular echodensities in preterms and neurodevelopmental outcome.

Little is known about the clinical evolution and neurologic sequelae of transient periventricular echodensities in the neonatal period. The aim of our study was to assess the neurodevelopmental outcome in preterm infants with transient periventricular echodensities. Cerebral ultrasonography was performed within the first 72 hours of life on all preterms with a < or = 37 weeks' gestational age who were admitted consecutively to the Neonatal Intensive Care Unit of the University of Parma from January 2001 to December 2002. Cerebral ultrasonography was performed at least twice within the 14th postnatal day and was repeated weekly until 40 weeks' postconceptional age. Transient aspecific echodensities were defined as areas in the periventricular region brighter than the choroid plexus persisting less than 14 days. One hundred sixty-four preterm infants were selected and divided into three groups: (1) 78 preterm infants without ultrasound abnormalities, (2) 50 preterm infants with transient periventricular echodensities, and (3) 36 preterm infants with persistent echodensities. Developmental outcome was assessed at 44 weeks' postconceptional age, after 1 month from the discharge and at the corrected ages of 3, 6, 9, and 12 months using the Griffiths Mental Developmental Scale. Group 1 and 2 infants showed normal neurodevelopment in 88.5% and 94% of cases, respectively, whereas the preterm infants belonging to group 3 had a favorable outcome in 22.2% (P < .001) of cases only. In conclusion, our study demonstrates how infants with transient echodensities show a neurodevelopmental outcome that is entirely identical to infants with a steadily negative ultrasound finding.

Cerebral Ventricles↗

PubMed2007

Role of the prostaglandins in labour and prostaglandin receptor inhibitors in the prevention of preterm labour.

Parturition is composed of five separate but integrated physiological events: fetal membrane rupture, cervical dilatation, myometrial contractility, placental separation, and uterine involution. Prostaglandins (PGs) have central roles in each of these events, but the most studied is myometrial contraction. Elevated uterine PGs or the enhanced sensitivity of the myometrium to PGs leads to contractions and labour. The primary regulator of PG synthesis is the mRNA expression of PG H Synthase (PGHS-2 or COX-2). Given the central role of PGs in labour, this enzyme becomes an obvious therapeutic target for the prevention of preterm labour, the major cause of perinatal mortality and morbidity. Unfortunately, even though the non-steroidal anti-inflammatory drugs (NSAIDs), which inhibit PGHS, are usually successful in suppressing preterm labour or prolonging pregnancy in animal and human studies, the NSAIDS have had adverse effects on fetal physiology and development. Therefore, other means to suppress PG synthesis or action to arrest preterm labour need to be investigated. The PGF2alpha receptor, FP, may prove to be a reasonable target for tocolysis. FP mRNA increases in the mouse uterus at preterm birth, whereas PGF2alpha concentrations do not increase, suggesting elevated uterine sensitivity to contractile agonists is one mechanism for preterm labour initiation. New data shows that administration of a specific FP antagonist, Theratechnologies (THG) 113.31, delays preterm birth in mice and sheep with no observable maternal or fetal side effects. Hence antagonizing PG action offers new hope for delaying preterm birth.

Animals↗

PubMed2003

[Bone turnover and early parenteral calcium supply in preterm infants].

OBJECTIVE: To explore the dynamic change in biochemical markers of bone turnover in preterm infants and the effect of early parenteral calcium supply. METHODS: Forty preterm infants were divided into parenteral calcium supply group and control group. Blood and urine samples were collected at 24 h and 11 d after birth. Serum osteocalcin (OC) was measured with ELISA, serum carboxyterminal telopeptide type I collagen (ICTP) with radioimmunoassay, serum alkaline phosphatase (AKP), calcium, phosphate, and urine calcium, phosphate, creatinine with automatic biochemical analyzer. Blood samples were also collected from 22 term infants as control. Calcium gluconate (10%, 4 ml/kg x d(-1)) was administered intravenously in parenteral calcium supply group. RESULT: At 24 h, serum AKP, ICTP [(147.86+/- 44.87)IU, (57.36+/- 6.34)micro g/L] in preterm infants were significantly higher than those [(147.86+/- 44.87)IU, (57.36+/- 6.34)micro g/L] in term infants, and negatively correlated with gestational age and birth weight (r =-0.528, P<0.01; -0.614, P< 0.01), but serum OC [(648.77+/- 238.89) nmol/L] in preterm infants was lower than that [(851.68+/- 238.69)nmol/L] of term infants, and positively correlated with gestational age and birth weight (r=0.359, P< 0.05; 0.376, P< 0.01). At 11 day, serum OC [947.25+/- 335.47)nmol/L] in preterm infants was markedly elevated and reached the level of term infants [(941.65+/- 297.28)nmol/L], but serum ICTP [(65.44+/- 6.24)micro g/L] in preterm infants was higher than that [(57.10+/- 3.48)micro g/L] in term infants all along. Serum AKP [(246.00+/-66.64)IU] in parenteral calcium supply group was higher than that [(206.53+/- 53.9)IU] in the control group. There were no significantly differences in serum OC and ICTP between parenteral calcium supply group and the control group. Calcium in serum and urine was elevated, phosphate in serum and urine was reduced in the parenteral calcium supply group. Urine analysis and kidney ultrasounds were normal. CONCLUSION: There is active bone formation and bone resorption in preterms as compared with terms. Alone parenteral calcium supply during early life can not increase formation of bone protein or decrease degradation of bone collagen, but can elevate serum calcium and urine calcium levels. Hematuria and renal calcification were not found in short duration.

Alkaline Phosphatase↗

PubMed1999

Preterm labor.

Preterm labor is the leading cause of perinatal morbidity and mortality in the United States. It is characterized by cervical effacement and/or dilatation and increased uterine irritability before 37 weeks of gestation. Women with a history of preterm labor are at greatest risk. Strategies for reducing the incidence of preterm labor and delivery have focused on educating both physicians and patients about the risks for preterm labor and methods of detecting preterm cervical dilatation. Methods used to predict preterm labor include weekly cervical assessment, transvaginal ultrasonography, detection of fetal fibronectin and home uterine activity monitoring. As yet, it is unclear if any of these strategies should be routinely employed. At present, management of preterm labor may include the use of tocolytic agents, corticosteroids and antibiotics.

Female↗

PubMed2001

Maternal serum tumor necrosis factor-alpha in patients with preterm labor.

OBJECTIVE: To evaluate maternal serum tumor necrosis factor-alpha (TNF alpha) levels in patients with preterm labor without clinical signs of chorioamnionitis and to compare these with levels in nonlaboring controls. STUDY DESIGN: The study group consisted of 44 patients with a singleton pregnancy admitted to our department with the diagnosis of preterm labor between 26 and 36 weeks' gestation. The control group consisted of 25 healthy consecutive patients with a singleton pregnancy without preterm contractions who were seen for routine antenatal visits. Maternal serum TNF alpha was measured using a solid-phase, two-site chemiluminescent enzyme immunometric assay method, and levels were compared in patients with preterm labor and nonlaboring controls. RESULTS: The median maternal serum TNF alpha level for patients with preterm labor was 29.4 pg/mL (range, 12.3-173) as compared with 23 pg/mL (range, 11.9-62.7) in the control group (P = .031). Among 44 patients with preterm labor, 14 (32%) delivered within one week of admission. The median maternal serum TNF alpha level was significantly higher in patients who delivered within one week than in those who delivered after one week and controls (71.3 pg/mL [range, 28-173]) versus 22 pg/mL (range, 12.3-86) versus 23 pg/mL (range, 11.9-62.7) (P < .0001). CONCLUSION: TNF alpha was elevated in patients with preterm labor, suggesting a role for maternal serum TNF alpha in its initiation.

Adult↗

PubMed2001

A randomized clinical trial of care for women with preterm labour: home management versus hospital management.

BACKGROUND: Preterm labour occurs in about 10% of all pregnancies and is the most important cause of premature birth. Women with preterm labour are admitted to hospital to have the contractions stopped. Thereafter, many women remain in hospital until delivery. We conducted a randomized clinical trial to compare hospital care with home care of women who had been admitted to hospital for preterm labour. METHODS: After they had received treatment for an acute episode of premature labour, women at 2 regional perinatal centres associated with teaching hospitals were randomly assigned to home care or hospital care. Eligible women (n = 250) were aged 18 years or older, lived within 50 km of the hospital, had a gestational age between 20 and 35 weeks, had no prior preterm delivery and were experiencing their first episode of preterm labour and first admission to hospital for preterm labour. Analysis was by intention to treat. RESULTS: There were no significant differences between the 2 groups in mean gestational age at delivery (home: 37.52 weeks, hospital: 37.50 weeks) or in mean birth weight (home: 2974 g, hospital: 3020 g). There were no significant differences between the 2 groups with respect to the proportions of babies born before term or the mean duration of neonatal hospital stay, neonatal intensive care unit stay and intermediate care nursery stay. The mean duration of the first stay in hospital for the women in the home group (3.8 days) was significantly shorter than the mean duration for women in the hospital group (6.1 days). In addition, the mean duration of all maternal stays in hospital was significantly shorter for the women in the home group (3.7 days) than in the hospital group (5.0 days). INTERPRETATION: Home care management is an efficient and acceptable alternative to hospital care for women experiencing preterm labour.

Adolescent↗

PubMed2001

[Tocolysis, use of beta-sympatomimetics for threatening preterm delivery: a critical review].

Use of beta-sympatomimetics for threatening preterm delivery: a critical review. Preterm birth is the principal cause of perinatal and neonatal mortality and morbidity. Over the past 40 years, numerous treatments have been tested and used to try to inhibit preterm labor. This literature review is limited to the published studies of beta-adrenergic agonists (beta-sympathomimetics). Among 36 articles that have examined the treatment of acute phase preterm labor by intravenous beta-sympathomimetic administration, 26 are clinical studies with severe biases that make them unacceptable for analysis: non-randomized clinical trials, retrospective studies or retrospective control groups, inadequate recording of pregnancy outcome, exclusion of patients after randomization, confounding factors due to the use of multiple therapeutic agents, inadequate study power.Of the 10 acceptable placebo-controlled trials, seven, including the largest (the Canadian Preterm Labor Investigators' Group, with 708 women), found that beta-sympathomimetics were not better than placebo in prolonging pregnancy or reducing neonatal morbidity. Only three studies found that they were superior to placebo. These agents cause numerous maternal side effects that may be life-threatening, because beta-adrenergic receptors are present in many organs. The cardiovascular system is the most severely affected, but side effects also concern the pancreas, kidneys, intestines, and liver. beta-Sympathomimetics cross the placenta rapidly. Fetuses probably respond in the same way their mothers do to stimulation of their beta-adrenergic receptors. Nonetheless, data from the controlled clinical trials show no difference in neonatal mortality or severe morbidity between children born to mothers treated with beta-sympathomimetics and those born to mothers in control groups. The efficacy of preventive treatment by oral or subcutaneous administration of beta-sympathomimetics has also been assessed: a meta-analysis and 2 large randomized placebo-controlled trials have showed that oral maintenance treatment offers no advantages over placebo during the latency phase or for the recurrence rate of preterm labor and the rate of preterm delivery. A single - and smaller - placebo-controlled study found that oral maintenance treatment with ritodrine was beneficial. Treatment trials of subcutaneous administration of beta-sympathomimetics have been performed with a portable subcutaneous pump. Ten studies of this method have been reported, but only two were randomized trials. They found no significant difference in either the mean time until delivery or neonatal morbidity.

Adrenergic beta-Agonists↗

PubMed2001

[Zinc levels in term and preterm milk].

Zinc is an essential element, important for early growth and development, and immune competence, which deficiency might be especially critical in preterm infants. Since published data have shown that some preterm milks have abnormally low zinc values, we decided to measure zinc levels in term and preterm milk, in order to assess if they were within normal values and if there were differences between both groups. Samples from 24 preterm and 20 term mothers (mean gestational age, 30.9 + 0.5 and 39.5 + 0.2 weeks, respectively) were collected and kept at -20 degrees C until analyzed by atomic absorption spectrophotometry, prior wet ashing with nitric acid. Both term and preterm milk showed zinc values within normal levels. No significant differences were registered between them. A decreasing trend was observed along time, which was significant between colostrum and mature milk samples (ANOVA, p < 0.05). In the term group, zinc concentrations in colostrum and mature milk (microgram/mL) (mean +/- SEM) varied between 6.96 +/- 0.69 y 2.44 +/- 0.11, while in the preterm group the values were 6.20 +/- 0.89 y 2.28 +/- 0.54. According to our results, zinc values in human milk were comparable between preterm and term mothers.

Analysis of Variance↗

PubMed2001

ACOG Practice Bulletin. Assessment of risk factors for preterm birth. Clinical management guidelines for obstetrician-gynecologists. Number 31, October 2001. (Replaces Technical Bulletin number 206, June 1995; Committee Opinion number 172, May 1996; Committee Opinion number 187, September 1997; Committee Opinion number 198, February 1998; and Committee Opinion number 251, January 2001).

Preterm birth is the second leading cause of neonatal mortality in the United States (1) (second only to birth defects), and preterm labor is the cause of most preterm births (2). Neonatal intensive care has improved the survival rate for babies at the cusp of viability, but it also has increased the proportion of survivors with disabilities. The incidence of multiple births also has increased along with the associated risk of preterm delivery (4). Interventions to delay preterm delivery in these settings have not shown conclusive effectiveness. Because the morbidity of babies born after 34-35 weeks of gestation has diminished, most efforts to identify preterm deliveries have focused on deliveries before this age. This document describes the various methods proposed for predicting preterm birth and the evidence for their roles in clinical practice.

Cervix Uteri↗

PubMed2002

Preterm labour--is bacterial vaginosis involved?

OBJECTIVE: To assess the efficacy of treatment of bacterial vaginosis (BV) using metronidazole to reduce preterm labour in primigravidae and multigravidae with previous midtrimester abortion or preterm labour. DESIGN: Randomised controlled trial. SETTING: Tertiary academic hospital. METHOD: Two different groups of patients were screened for BV at the first antenatal visit, namely primigravidae and high-risk multigravidae who had had a previous midtrimester abortion or preterm delivery. Patients where BV was diagnosed clinically or on Gram's stain of a smear taken from the posterior vaginal fornix, received either 400 mg metronidazole, or 100 mg vitamin C orally twice daily for 2 days. The Gram's stain was repeated after 4 weeks. If BV was found again, treatment with the same drug was repeated. OUTCOME MEASURES: Preterm delivery, birth weight and perinatal deaths. RESULTS: One thousand and five patients entered the study, but 40 were excluded for various reasons and 10 were lost to follow-up. There were 464 primigravidae, of whom 150 (32%) had BV. Except for the 5-minute Apgar score, no significant differences were found between primigravidae negative for BV and those who received either metronidazole or vitamin C. There were 491 high-risk multigravidae, of whom 127 (26%) had BV. The mean gestational age in the BV-negative group was 37 weeks, in contrast to 37.4 weeks in the vitamin C group and 35.6 weeks in the metronidazole group. Birth weights in these three groups were 2,752 g, 2,759 g and 2,475 g respectively, significantly less (P = 0.0109) in the metronidazole group in comparison with the BV-negative group. Delivery before 37 weeks occurred in 29% of high-risk multigravidae with no BV but in 24% of those who took vitamin C and in 43% who took metronidazole. Differences were significant between the BV-negative and metronidazole groups (P = 0.0231) and also between the metronidazole and vitamin C groups (P = 0.0274). Delivery before 28 weeks occurred in 4% of the high-risk multigravidae with no BV but in 10% of those with BV who took metronidazole. The difference was significant (P = 0.0430). Analysis for maximum likelihood estimates for preterm labour identified only previous preterm labour or midtrimester abortion as risk factors. CONCLUSION: Metronidazole does not seem to reduce the prevalence of preterm labour when given for BV before 26 weeks' gestation.

Adult↗

PubMed2002

Redistribution of corticotropin-releasing hormone receptor R2 using fluorescence immunohistochemistry in fetal membranes of women delivering preterm or at term.

OBJECTIVE: The aim of our study was to determine whether a difference exists in expression of corticotropin-releasing hormone receptor-R1 (CRH-R1) and corticotropin-releasing hormone receptor-R2 (CRH-R2) in fetal membranes of preterm and term women with or without labor. MATERIAL AND METHODS: Small pleces of fetal membranes were obtained from the placenta of each of forty patients undergoing cesarean section. Ten samples each were taken from preterm and term patients, with and without labor. Antibodies against CRH-R1/2 and CRH-R2 were used for localization by conventional fluorescence immunohistochemistry. The evaluation of staining was based on examination of the entire histologic section by three independent observers. RESULTS: In women at term without labor, CRH-R2 receptor was predominantly expressed in the amniotic epithelium and the amniotic mesenchyme. In laboring women at term, the expression of CRH-R2 receptor was shown in the chorionic mesenchyme and the cytotrophoblast cells, but no specific staining could be detected in the amniotic membranes. Changes in CRH-R2 receptor expression could not be demonstrated during preterm labor of early pregnancies. In preterm women, the antibody against CRH-R1/2 receptor detected additional signals in the amniotic mesenchyme and epithelium, suggesting expression of CRH-R1 in these tissues. In women at term, the overlapping pattern of CRH-R1/2 was recognized in both the chorionic and amniotic mesenchyme, in contrast to the specific CRH-R2 staining, suggesting expression of CRH-R1 in the mesodermal cell compartments. CONCLUSION: At term, changes in CRH-R2 expression are directly related to the progression of normal labor; such changes were not observed during preterm labor of early pregnancies. The increased CRH-R2 expression in the chorionic mesenchyme may possibly provoke rupture of the membranes or at least play a role in some key regulatory events in the initiation of normal labor. The fact that this mechanism does not occur in preterm labor strengthens the hypothesis that onset of labor could be controlled by distinct mechanisms in preterm and term pregnancies.

Amnion↗