PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Preterm”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources

Treatment for cervical intraepithelial neoplasia and risk of preterm delivery.

CONTEXT: It is unclear whether treatments for cervical intraepithelial neoplasia (CIN) increase the subsequent risk of preterm delivery. Most studies have lacked sufficient sample size, mixed heterogeneous subtypes of preterm delivery, and failed to control for confounding factors. OBJECTIVE: To determine whether cervical laser and loop electrosurgical excision procedure (LEEP) treatments increase risk of preterm delivery and its subtypes. DESIGN, SETTING, AND PARTICIPANTS: Retrospective cohort study conducted among women evaluated at a colposcopy clinic serving Auckland, New Zealand (1988-2000), comparing delivery outcomes of untreated women (n = 426) and those treated (n = 652) with laser conization, laser ablation, or LEEP. Record linkage using unique health identifiers identified women who had subsequent deliveries. MAIN OUTCOME MEASURES: Total preterm delivery and its subtypes, spontaneous labor and premature rupture of membranes before 37 weeks' gestation (pPROM). RESULTS: The overall rate of preterm delivery was 13.8%. The rate of pPROM was 6.2% and the rate of spontaneous preterm delivery was 3.8%. Analyses showed no significant increase in risk of total preterm delivery (adjusted relative risk [aRR], 1.1; 95% confidence interval [CI], 0.8-1.5) or spontaneous preterm delivery (aRR, 1.3; 95% CI, 0.7-2.6) for any treatment. Risk of pPROM was significantly increased following treatment with laser conization (aRR, 2.7; 95% CI, 1.3-5.6) or LEEP (aRR, 1.9; 95% CI, 1.0-3.8), but not laser ablation (aRR, 1.1; 95% CI, 0.5-2.4). Moreover, risk of pPROM and total preterm delivery increased significantly with increasing height of tissue removed from the cervix in conization. Women in the highest tertile of cone height (> or =1.7 cm) had a greater than 3-fold increase in risk of pPROM compared with untreated women (aRR, 3.6; 95% CI, 1.8-7.5). CONCLUSIONS: LEEP and laser cone treatments were associated with significantly increased risk of pPROM. Careful consideration should be given to treatment of CIN in women of reproductive age, especially when treatment might reasonably be delayed or targeted to high-risk cases.

Cervix Uteri↗

Prenatal administration of progesterone for preventing preterm birth.

BACKGROUND: Preterm birth is the major complication of pregnancy associated with perinatal mortality and morbidity and occurs in up to 6% to 10% of all births. Administration of progesterone for the prevention of preterm labour has been advocated. OBJECTIVES: To assess the benefits and harms of progesterone administration during pregnancy in the prevention of preterm birth. SEARCH STRATEGY: We searched the Cochrane Pregnancy and Childbirth Group's Specialised Register of Controlled Trials (March 2005), the Cochrane Central Register of Controlled Trials (The Cochrane Library, Issue 3, 2004), MEDLINE (1965 to January 2005), EMBASE (1988 to August 2004), and Current Contents (1997 to August 2004). SELECTION CRITERIA: All published and unpublished randomised controlled trials, in which progesterone was given by any route for preventing preterm birth. DATA COLLECTION AND ANALYSIS: Standard methods of the Cochrane Collaboration and the Cochrane Pregnancy and Childbirth Group were used. Evaluation of methodological quality and trial data extraction were undertaken independently by two authors. Results are presented using relative risk with 95% confidence intervals. MAIN RESULTS: For all women administered progesterone, there was a reduction in the risk of preterm birth less than 37 weeks (six studies, 988 participants, relative risk (RR) 0.65, 95% confidence interval (CI) 0.54 to 0.79) and preterm birth less than 34 weeks (one study, 142 participants, RR 0.15, 95% CI 0.04 to 0.64). Infants born to mothers administered progesterone were less likely to have birthweight less than 2500 grams (four studies, 763 infants, RR 0.63, 95% CI 0.49 to 0.81) or intraventricular haemorrhage (one study, 458 infants, RR 0.25, 95% CI 0.08 to 0.82). There was no difference in perinatal death between women administered progesterone and those administered placebo (five studies, 921 participants, RR 0.66, 95% CI 0.37 to 1.19). There were no other differences reported for maternal or neonatal outcomes. AUTHORS' CONCLUSIONS: Intramuscular progesterone is associated with a reduction in the risk of preterm birth less than 37 weeks' gestation, and infant birthweight less than 2500 grams. However, other important maternal and infant outcomes have been poorly reported to date, with most outcomes reported from a single trial only (Meis 2003). It is unclear if the prolongation of gestation translates into improved maternal and longer-term infant health outcomes. Similarly, information regarding the potential harms of progesterone therapy to prevent preterm birth is limited. Further information is required about the use of vaginal progesterone in the prevention of preterm birth.

17-alpha-Hydroxyprogesterone↗

Multisensory stimulation for promoting development and preventing morbidity in preterm infants.

RATIONALE: Multisensory stimulation is a structured, developmentally appropriate intervention that provides simultaneous or sequential stimulation of two or more senses (e.g. tactile, auditory, visual, or vestibular) in a controlled and non-stressful manner, with the aim of supporting early neurodevelopment in preterm infants. It has the potential to enhance physiological regulation in preterm infants by stabilizing key functions, such as respiratory patterns, heart rate, and oxygen saturation; reducing the need for respiratory support; and improving feeding performance and sleep regulation. Targeted multisensory interventions have also been associated with improved neurodevelopmental outcomes, including enhanced psychomotor development and visual function. OBJECTIVES: To assess the benefits and harms of multisensory stimulation compared to any single sensory intervention or standard care on major neurodevelopmental disability, mortality, and growth in preterm infants. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, Emcare, CINAHL, Epistemonikos, two trial registries, and conference abstracts up to 28 November 2025. We checked reference lists of included trials, and systematic reviews on sensory interventions. ELIGIBILITY CRITERIA: We included 18 randomized controlled trials (RCTs) comparing multisensory stimulation in preterm infants with no intervention (placebo or standard care), and one RCT comparing multisensory stimulation with single-sense stimulation (tactile stimulation). OUTCOMES: Our critical outcomes were major neurodevelopmental disability at 18 to 24 months: cerebral palsy (CP), developmental delay, intellectual impairment, blindness, sensorineural deafness; death during initial hospitalization; and total weight gain (grams), assessed at discharge. When comparing multisensory stimulation with single-sense intervention, we also included weight gain during the intervention, an outcome added during the post-hoc analysis. Important outcomes were duration of hospital stay, of NICU stay, and of respiratory support; and time until full oral feeding. RISK OF BIAS: We used the Cochrane tool, RoB 2. SYNTHESIS METHODS: We conducted meta-analyses using fixed-effect models to calculate risk ratios (RR) for dichotomous data, and mean differences (MDs) for continuous data, each with its 95% confidence intervals (CIs). We assessed statistical heterogeneity by calculating the I2 statistic when we included more than two trials in a meta-analysis. We evaluated the certainty of evidence using GRADE. INCLUDED STUDIES: We included 19 trials (1554 newborn infants): 18 studies compared multisensory stimulation with standard care; one compared multisensory stimulation with single-sensory stimulation (tactile). In 10 studies, the primary aim was to assess the neurobehavioral outcomes of multisensory stimulation on preterm neo-nates. The other nine studies aimed to assess the impact of multisensory stimulation on weight gain during the intervention, weight gain until hospital discharge, length of neonatal intensive care unit (NICU) stay, length of hospital stay, time until full oral feeding, length of respiratory support, or a combination. In the abstract we report results for the critical outcomes only. We identified 13 ongoing studies. Four studies are awaiting assessment. SYNTHESIS OF RESULTS: Multisensory stimulation compared to standard care No studies reported on these major neurodevelopmental disabilities, assessed at 18 to 24 months' corrected age (CA): developmental delay, intellectual impairment, blindness, or sensorineural deafness. One study reported on rates of CP at 12 months of age. The evidence is very uncertain about the effect of multisensory stimulation on CP (RR 0.67, 95% CI 0.28 to 1.58; I² not applicable; 1 study, 18 participants; very low-certainty evidence). The evidence suggests that multisensory stimulation may result in little to no difference in death during initial hospitalization (RR 0.97, 95% CI 0.54 to 1.73; I² not applicable; 1 study, 395 participants; low-certainty evidence). Multisensory stimulation may increase total weight gain prior to discharge (MD 72.67, 95% CI 68.23 to 77.12; I² = 0%; 3 studies, 474 participants; low-certainty evidence). Multisensory stimulation compared to single-sense (tactile) stimulation No studies reported on major neurodevelopmental disability, assessed at 18 to 24 months' CA, or death during initial hospitalization. The evidence is very uncertain about the effect of multisensory stimulation compared to tactile stimulation on weight gain during the intervention (MD -175.00, 95% CI -376.60 to 26.60; I² not applicable; 1 study, 20 participants; very low-certainty evidence). The certainty of the evidence was low to very low across outcomes, primarily due to risk of bias, imprecision from small sample sizes and wide CIs, and in some cases, inconsistency. The evidence base was also limited by the lack of reporting of relevant outcomes and reliance on surrogate outcomes or shorter follow-up periods. AUTHORS' CONCLUSIONS: The available evidence on multisensory stimulation in preterm infants is limited and of low to very low certainty. No included studies reported on major neurodevelopmental disabilities at 18 to 24 months' CA, which represented a critical outcome for this review. Evidence regarding the effect of multisensory stimulation on CP is very uncertain, as it is based on a single small study reporting a surrogate outcome at 12 months. Multisensory stimulation may result in little to no difference in mortality during the initial hospitalization. It may increase total weight gain prior to discharge. However, the clinical significance of this finding is uncertain, particularly given the low certainty of the evidence and the multifactorial nature of growth in preterm infants. The evidence is very uncertain about the effect of multisensory stimulation compared to single-sense (tactile) stimulation on weight gain during the intervention. The only included study did not report major neurodevelopmental disabilities at 18 to 24 months' CA, mortality during the initial hospitalization, or total weight gain prior to discharge, which represented the critical outcomes for this review. Overall, the current evidence does not allow firm conclusions about the effectiveness of multisensory stimulation in promoting development or preventing morbidity in preterm infants. Future studies on multisensory stimulation should use more rigorous designs, larger samples, and report interventions using the template for intervention description and replication (TIDieR) checklist to ensure transparency. They should also report essential outcomes, such as neonatal death, major neurodevelopmental disabilities, length of hospital and NICU stay, time to full oral feeding, duration of respiratory support, and weight gain, to better assess the long‑term effects of multisensory stimulation in preterm infants. FUNDING: This Cochrane review had no dedicated funding. REGISTRATION: Protocol available via DOI: 10.1002/14651858.CD016073.

Humans↗

Factors associated with preterm delivery in mothers of children with Beckwith-Wiedemann syndrome: a case cohort study from the BWS registry.

Pregnancy that results in a child with Beckwith-Wiedemann syndrome (BWS) is associated with preterm delivery. Based on previous case series, we hypothesized that preterm delivery of a child with BWS was due to known risk factors for preterm delivery such as polyhydramnios and gestational hypertension. A case cohort study using the BWS Registry at Washington University School of Medicine was undertaken. Cases were pregnancies that resulted in the birth of a child with BWS, controls were pregnancies resulting in the birth of siblings without BWS. Univariate analyses of maternal complications and logistic regression to predict preterm delivery were used. Children with BWS (n = 304) were delivered preterm at a significantly higher rate than their siblings (n = 269) odds ratio 19.1 (95% CI 9.1-40.2). Polyhydramnios, gestational hypertension, and vaginal bleeding also occurred at high rates in the BWS group with odds ratios of 31.6 (95% CI 12.6-79.1), 2.4 (95% CI 1.4-4.1), and 3.9 (95% CI 2.3-6.4), respectively. In a multivariate logistic regression model within the BWS group, polyhydramnios, vaginal bleeding, and gestational hypertension were significant predictors of preterm delivery, odds ratios of 2.9 (95% CI 1.6-5.4), 2.6 (95% CI 1.3-5.0), and 5.3 (2.3-12.0), respectively. However, a significant proportion, 6.5% (18 of 277), of patients in the BWS group delivered preterm without known risk factors. Preterm delivery of a child with BWS is associated with an increased frequency of polyhydramnios, gestational hypertension, and vaginal bleeding in the mother. However, preterm delivery also occurs in the absence of these risk factors.

Adolescent↗

First-trimester uterine artery Doppler and spontaneous preterm delivery.

OBJECTIVES: To assess the relationship between first-trimester uterine artery Doppler measurements and spontaneous preterm delivery. METHODS: This was a retrospective analysis of uterine artery Doppler findings at 11-14 weeks in 73 singleton pregnancies with spontaneous preterm labor and 2417 pregnancies delivered at term. RESULTS: The uterine artery mean resistance index (RI) was 0.68 (coefficient of variation 19%) and 0.69 (17%) in the preterm and term delivery groups, respectively (P = 0.35). The mean pulsatility index (PI) was 1.42 (39%) and 1.42 (46%) in the term and preterm delivery groups, respectively (P = 0.95). Bilateral diastolic notches were present in 34% of preterm deliveries and 33% of controls (P = 0.84). Restricting the analysis to the 19 pregnancies with preterm delivery before 34 weeks of gestation, no significant difference from controls was observed for RI (mean 0.71, coefficient of variation 11%, P = 0.41), PI (mean 1.56, coefficient of variation 29%, P = 0.27) or the number of bilateral notches (42%, P = 0.41). CONCLUSIONS: Despite pathological evidence suggesting that defective placentation is associated with spontaneous preterm delivery, first trimester uterine artery resistance, as assessed by Doppler ultrasound investigation, is not different in pregnancies subsequently complicated by preterm labor compared to pregnancies delivered at term. This finding may be explained by a late failure of trophoblast development in cases destined to deliver preterm.

Adult↗

Neurological outcome in high risk weight appropriate for gestational age preterm children at early school age.

Neurological development in preterm children with birth weight appropriate for gestational age is reported in two separate groups: a longitudinal study of 97 preterm children and 93 term children as a control group and a cross-sectional study of 249 preterm children. Both preterm groups were regarded as high risk with respect to number of outborns, distribution of gestational age and perinatal risk factors. Neurological outcome at 5-6 years of age in the majority of the preterm children was comparable to that of the term children. However, 15% of boys and 9% of girls in the preterm group were diagnosed as having cerebral palsy. Mild diplegia was most frequently observed; 4% of the children were severely impaired. Fourteen percent of the preterm vs 2% of the term boys and 6-9% of the preterm vs none of the term girls received motor therapy during early school age. There was a small but consistent sex difference in neurological outcome in favour of the term and preterm girls. Effects of drop out rate and of incompleteness of ascertainment are reported in detail.

Birth Weight↗

Hypercalciuria in ex-preterm children, aged 7-8 years.

In a previous study, 8 of 28 ex-preterm infants, aged 4-5 years, had increased urinary calcium excretion. The aim of this study was to confirm this finding and to determine if raised urinary calcium excretion is associated with reduced bone mineralisation. Forty-six ex-preterm children, aged 7-9 years, and 40 age- and sex-matched controls were recruited. The calcium excretion measured from 3 separate 24-h urine collections was recorded and a dietary assessment made from a diary record. Data were retrieved from the neonatal case notes and included aminoglycoside usage. Dual energy X-ray absorptiometry was used to measure bone mineral content and bone mineral density (BMD) in all children. The mean maximum 24-h urinary calcium was significantly higher in the preterm group than the term group (P=0.01). Increased calcium excretion was associated with raised neonatal aminoglycoside levels (P=0.0013). Height standard deviation score and hip BMD were significantly lower in the 21 preterm children with a 24-h urinary calcium above 4 mg/kg per day than term controls (P=0.04 and P=0.004, respectively). Urinary calcium excretion had a negative relationship with hip BMD in the preterm group (P=0.004). This difference in BMD was not observed in the 25 preterm children with normocalciuria. In the 10 preterm girls with hypercalciuria, hip BMD was lower than in control females (P=0.01). This difference in hip BMD between the 11 preterm boys with hypercalciuria and term boys was not significant (P=0.05). In conclusion, preterm children are shorter and have a lower hip BMD than those with normocalciuria. Further prospective studies are required to assess this risk and its influence on subsequent impaired bone mineralisation.

Anthropometry↗

State-specific trends in preterm delivery: are rates really declining among non-Hispanic African Americans across the United States?

OBJECTIVES: This study sought to examine state-specific trends in preterm delivery rates among non-Hispanic African Americans and to assess whether these rates are influenced by misclassification of gestational age. METHODS: The sample population consisted of singleton non-Hispanic White and non-Hispanic African-American infants born in 1991 and 2001 to U.S. resident mothers. For both time periods, state-specific and national preterm delivery rates were calculated for all infants, stratified by infant race/ethnicity. Next, birth-weight distributions within strata of gestational age were studied to explore possible misclassifications of gestational age. Lastly, state-specific and national preterm delivery rates among infants who weighed less than 2,500 g were separately computed. RESULTS: National analyses showed that the frequency of preterm delivery increased by 15.8% among non-Hispanic Whites but declined by 10.3% among non-Hispanic African Americans over the same period. For both subgroups, a bimodal distribution of birth weights was apparent among preterm births at 28-31 weeks of gestation. The second peak with its cluster of normal-weight infants was more prominent among non-Hispanic African Americans in 1991 than in 2001. After excluding preterm infants who weighed 2,500 g or more, the national trends persisted. State-specific analyses showed that preterm delivery rates increased for both subgroups in 13 states during this period. Of these 13, 6 states had a number of non-Hispanic African-American births classified as preterm that were apparently term births mistakenly assigned short gestational ages. Such misclassification was more frequent in 1991 than in 2001 and inflated 1991 rates. CONCLUSION: There is heterogeneity in state-specific preterm delivery rates. Such differences are often overlooked when aggregate results are presented.

Adolescent↗

Warning symptoms, uterine contractions, and cervical examination findings in women at risk of preterm delivery.

The presence of various reputed warning signs of preterm labor, the frequency of contractions, and the presence of cervical examination findings and their value in predicting preterm labor and spontaneous preterm delivery were assessed. The frequency of contractions and all cervical examination findings increased during pregnancy, as did backache, pressure, and cramping. The frequency of diarrhea, discharge, and bleeding remained constant. Of the various warning signs, only diarrhea and discharge were associated with the diagnosis of preterm labor. None of the warning signs were associated with spontaneous preterm delivery. Various patterns of contractions tended to be associated with higher rates of preterm labor and preterm delivery, but results were generally not statistically significant. Most cervical examination findings were statistically associated with both preterm labor and preterm delivery.

Adult↗

Antibiotic treatment of preterm labor with intact membranes: a multicenter, randomized, double-blinded, placebo-controlled trial.

OBJECTIVE: Although an association between subclinical intrauterine infection and preterm birth is well established, there is conflicting evidence regarding the benefits of antibiotic administration to women in preterm labor with intact membranes. We attempted to determine the effect of ampicillin-amoxicillin and erythromycin treatment on prolongation of pregnancy, the rate of preterm birth, and neonatal morbidity in patients with preterm labor and intact membranes. STUDY DESIGN: A multicenter, randomized, double-blinded, placebo-controlled trial was designed and implemented by the Maternal-Fetal Medicine Units Network of the National Institute of Child Health and Human Development. Two hundred seventy-seven women with singleton pregnancies and preterm labor with intact membranes (24 to 34 weeks) were randomly allocated to receive either antibiotics or placebos. RESULTS: Of the 2373 patients screened for participation in this study in six medical centers, 277 women were enrolled (n = 133 for antibiotics group vs n = 144 for placebo group). In each study group, 60% of patients completed all the study medications. The overall prevalence of microbial invasion of the amniotic cavity was 5.8% (14/239). No significant difference between the antibiotic group and the placebo group was found in maternal outcomes, including duration of randomization-to-delivery interval, frequency of preterm delivery (< 37 weeks), frequency of preterm premature rupture of membranes, clinical chorioamnionitis, endometritis, and number of subsequent admissions for preterm labor. Similarly, no significant difference in neonatal outcomes could be detected between the two groups including respiratory distress syndrome, bronchopulmonary dysplasia, intraventricular hemorrhage, sepsis, and admission and duration of newborn intensive special care unit hospitalization. CONCLUSION: The results of this study do not support the routine use of antibiotic administration to women in preterm labor with intact membranes.

Administration, Oral↗

Salivary estriol as risk assessment for preterm labor: a prospective trial.

OBJECTIVE: Increased understanding of human parturition allows for novel approaches to (1) identification of women at increased risk for preterm birth and (2) development and controlled testing of etiology-based strategies to prevent preterm birth. STUDY DESIGN: Five hundred forty-two women were enrolled at five study sites in a prospective evaluation of salivary estriol in samples obtained weekly beginning at 22 weeks' gestation (Salest, Biex, Inc., Boulder, Colo.). Estriol concentrations were determined with a well-characterized enzyme-linked immunoassay. Women adjudged at either high risk or low risk for prematurity were evaluated through to delivery. RESULTS: A total of 267 women submitted serial samples that were analyzed; 241 women with singleton pregnancies submitted sufficient samples. Twenty-three women with singleton fetuses went into idiopathic preterm labor (without prior rupture of membranes) and were delivered preterm (mean 35 weeks' gestation); 182 were delivered at term (> or = 37 weeks' gestation). Mean (geometric) estriol concentrations were higher from 24 to 34 weeks in women with singleton pregnancies delivering preterm (p < 0.05). A surge in estriol concentrations occurred approximately 3 weeks before the onset of labor in both women delivering at term and those delivering preterm. This increase occurred approximately 4 weeks earlier in women delivered preterm versus term. Receiver-operator curve analyses showed that exceeding a 2.3 ng/ml saliva estriol level was associated with occurrence of preterm labor (71% sensitivity, 77% specificity, 23% false-positive rate). CONCLUSION: Detection of an early estriol surge or increased level (> or = 2.3 ng/ml) may be clinically helpful in identifying women at elevated risk for preterm labor and birth, allowing for evaluation of biologically based interventions in controlled trials.

Adult↗

Comparison between the essential fatty acid status of preterm and full-term infants, measured in umbilical vessel walls.

The essential fatty acid (EFA) composition of umbilical vessel walls is increasingly being studied as a longer-term reflection of the fetal EFA status. We evaluated the EFA content of umbilical artery and vein vessel walls in 43 preterm infants and compared it with that of 43 full-term cord vessels. In addition, relations among cord vessel wall fatty acid composition, gestational age (GA) at birth, and anthropometric parameters at birth (weight, head circumference, and length) were explored in the preterm infants. Generally, n-6 and n-3 EFA levels were lower, while levels of EFA deficiency markers were higher in preterm than in term cords, both in the walls of the draining arteries and the supplying vein. In preterm cords, significant correlations were observed between GA at birth and levels of n-6 and n-3 EFAs (positive) and EFA deficiency markers (negative). Birth weight showed significant (P < or = 0.01), positive correlations with n-6 and n-3 EFA levels in the cord artery walls of preterm infants, all after correction for GA at birth. In conclusion, substantial differences between the EFA profiles of preterm and full-term cord vessel walls indicate a lower biochemical EFA status of the preterm than of the term fetus. This lower preterm EFA status might be a reflection of a physiologically lower EFA demand for growth and development of the preterm fetus than of the term fetus.

Fatty Acids, Essential↗

High turnover osteopenia in preterm babies.

Osteopenia is common in preterm babies, but its pathogenesis is uncertain. In this study bone density in babies was quantitated, postnatal bone mineralization compared to expected intrauterine bone mineralization and the pathogenesis of osteopenia investigated. Healthy babies (103 term, 76 preterm) were examined clinically, biochemically and radiologically the day after birth and at a time corresponding to expected full term gestation. Appendicular bone density was quantitated by magnification radiogrammetry, using the humeral cortical index (CI). The CI of preterm and term babies was similar the day after birth. In preterm babies elevated serum alkaline phosphatase and high urinary hydroxyproline indicated increased bone turnover. The CI of preterm babies at expected full term gestation was lower (p = 0.0001) than that of term babies at birth, implying that postnatal bone mineralization lagged behind expected intrauterine bone mineralization. Radiologic data suggested increased endosteal resorption rather than decreased bone formation. At expected full term gestation the preterm babies had higher serum alkaline phosphatase and urinary calcium, phosphate, c-AMP and hydroxyproline (p = 0.0001) than term babies at birth, and 15% had periosteal reactions. The biochemical as well as the radiologic data therefore indicated high turnover osteopenia in preterm babies. We conclude that postnatal bone mineralization in preterm babies lagged significantly behind expected intrauterine bone mineralization and that the osteopenia observed in preterm babies is caused by increased bone resorption and not by decreased bone formation. The cause(s) of this high turnover osteopenia, however, remains to be ascertained.

Bone Density↗

Reducing the risk for preterm birth: evidence and implications for neonatal nurses.

The incidence of preterm birth has been slowly rising despite advances in obstetric health care. Neonatal nurses have ongoing contact with women who have had a preterm birth and, thus, who are at high risk to have another preterm birth. This article discusses current evidence about reducing risk for preterm birth. Although preterm birth cannot always be prevented, preconception care can help identify and modify maternal risk and promote optimal health before conception. Quality prenatal care, as defined by the Institute of Medicine, consists of continuing risk assessment, health promotion, and interventions to modify medical and psychosocial risk. When these 3 components are consistently applied, they may confer some protection against preterm birth. Women at highest risk for preterm birth need to seek prenatal care from an expert in maternal-fetal medicine. Women also need to learn about the common, subtle signs of preterm labor so they can recognize symptoms and quickly seek treatment. Neonatal nurses can provide critical information and anticipatory guidance to women at risk for preterm birth so they can make sound decisions about future pregnancies.

Evidence-Based Medicine↗

Interleukin-4 and -10 gene polymorphisms and spontaneous preterm birth in multifetal gestations.

OBJECTIVE: The purpose of this study was to determine the relationship between maternal and fetal carriage of different alleles of interleukin-4 and -10 genes and pregnancy outcome in multifetal gestations. STUDY DESIGN: Buccal swabs from mother-infant pairs of 73 multifetal gestations were assayed for polymorphisms at position -590 of the interleukin-4 gene and position -1082 of the interleukin-10 gene. Pregnancy outcome data were obtained subsequently. RESULTS: Spontaneous preterm birth occurred in 29 of the pregnancies (39.7%). A higher frequency of the interleukin-4 T allele was found among mothers with spontaneous preterm birth compared with mothers without spontaneous preterm birth (36.2% vs 18.2%; P=.02; odds ratio, 2.6; 95% CI, 1.1-5.9). Moreover, 20.7% of mothers who had spontaneous preterm birth were homozygous for the interleukin-4 T allele, as opposed to only 2.3% of mothers who did not have a spontaneous preterm birth (P=.01; odds ratio, 11.2; 95% CI, 1.2-69.5). Similarly, in 55.2% of the pregnancies that were complicated by spontaneous preterm birth, 2 fetuses carried the interleukin-4 T allele, compared with only 29.5% of the pregnancies that were not complicated by spontaneous preterm birth (p<.05; odds ratio, 2.9; 95% CI, 1.0-8.8). There was no relationship between mother and infant IL-10 genotype and spontaneous preterm birth. CONCLUSION: Maternal and fetal carriage of the interleukin-4 T allele is associated with an increased risk of spontaneous preterm birth in multifetal gestations.

Adult↗

Number and gestational age of prior preterm births does not modify the predictive value of a short cervix.

OBJECTIVE: This study was undertaken to determine whether the number and gestational age of prior preterm deliveries modifies the significance of endovaginal sonographic cervical length less than 25 mm for the prediction of recurrent preterm birth less than 35 weeks' gestation. STUDY DESIGN: Secondary analysis of a multicenter, blinded, observational study. Endovaginal ultrasonographic examinations were scheduled at 2-week intervals between 16 and 23 weeks' gestation in singleton pregnancies of 181 gravid women with at least 1 prior spontaneous preterm birth between 16 and 32 weeks' gestation. RESULTS: The earliest prior preterm birth occurred before 23 weeks in 61 women and at 23.0 to 31 weeks in 115; 5 had missing gestational age data. Cervical length was not different between these 2 groups both at the initial scan (median 38 vs 37 mm, P=.54) and considering the shortest ever observed cervical length over the entire study period (median 30 vs 30 mm, P=.97). Cervical length less than 25 mm was associated with spontaneous preterm birth less than 35 weeks for both groups (positive predictive value 80% vs 71%, P>.99). There were 134 women with 1 prior preterm delivery (74%) and 47 with 2 or more. Cervical lengths were not different between these 2 groups at the initial scan (median 36.5 vs 37 mm, P=.52) or over the entire study period (median 30 vs 32 mm, P=.31). The positive predictive value of cervical length less than 25 mm for subsequent spontaneous premature birth was not significantly higher in gravid women with multiple prior preterm births (100% vs 73%, P>.99). CONCLUSION: Neither the number nor the gestational age of prior preterm births modify the predictive value of a cervical length less than 25 mm at 16 to 19 weeks for recurrent spontaneous preterm birth.

Adult↗

Use of microbial cultures and antibiotics in the prevention of infection-associated preterm birth.

OBJECTIVE: The purpose of this study was to summarize recent evidence regarding infection-associated preterm birth and to make appropriate recommendations. Antepartum treatment of lower genital tract infection or bacterial colonization has been found to reduce the incidence of preterm birth in the case of asymptomatic bacteriuria and bacterial vaginosis in selected patients but has been proved to be ineffective for vaginal colonization with organisms such as Ureaplasma urealyticum and group B streptococcus. STUDY DESIGN: This is a clinical opinion based on a review of recent data related to 1) the association between lower genital tract infection and preterm birth and 2) antibiotic trials to prevent preterm birth. RESULTS: Antepartum treatment of lower genital tract infection or bacterial colonization has been found to reduce the incidence of preterm birth in the case of asymptomatic bacteriuria and bacterial vaginosis in selected patients, but has been proven to be ineffective for vaginal colonization with organisms such as Ureaplasma urealyticum and group B streptococcus. Large well-designed trials have shown that the routine administration of antibiotics to women with preterm labor and intact membranes is not beneficial; however, antibiotic regimens including macrolides are recommended for preterm premature rupture of the membranes. CONCLUSION: Large well-designed trials have shown that the routine administration of antibiotics to women with preterm labor and intact membranes is not beneficial; however, antibiotic regimens that include macrolides are recommended for preterm premature rupture of the membranes.

Anti-Bacterial Agents↗

Is a change in the vaginal flora associated with an increased risk of preterm birth?

OBJECTIVE: The purpose of this study was to determine if a change in the vaginal flora was associated with an increased risk of preterm birth, and to determine if metronidazole therapy before 32 weeks increased the risk of preterm birth. STUDY DESIGN: We compared cultures taken at 23 to 26 weeks of gestation with cultures taken at delivery from women enrolled in the Vaginal Infections and Preterm Birth study to analyze the association of changes in the vaginal flora with preterm birth. RESULTS: Metronidazole therapy before 32 weeks was associated with an increased risk of preterm birth (OR 1.5, 95%CI 1.05-2.1) in an unadjusted model. A change to heavy growth of Escherichia coli or Klebsiella pneumoniae at delivery was found to be associated with preterm birth (OR 2.4, 95%CI 1.6-3.8). After controlling for race, parity, prepregnancy weight <100 pounds, smoking or drinking during pregnancy, Trichomonas vaginalis, bacterial vaginosis, chlamydia, mycoplasmas, group B streptococcus, metronidazole therapy before 32 weeks, vaginal pH >5.0, and an increase in E coli or K pneumoniae , only prepregnancy weight <100 pounds (adjusted odds ratio [AOR] 2.07, 95%CI 1.01-4.21) and increased E coli or K pneumoniae in the vagina at delivery (AOR 2.99, 95%CI 1.37-6.53) were found to be significantly associated with preterm birth. CONCLUSION: An increase in E coli or K pneumoniae in the vagina is an independent risk factor for preterm birth. Changes in the vaginal flora may explain the increased risk of preterm birth seen with vaginal clindamycin or oral metronidazole therapy.

Administration, Intravaginal↗