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 1,117 records · Page 62Linked to original sources

Temperature differences during sleep between fullterm and preterm neonates at matched post-conceptional ages.

OBJECTIVE: Altered physiologic behaviors during sleep have been described for healthy preterm neonates at post-conceptional fullterm ages. These differences may reflect brain dysmaturity as a result of conditions of prematurity. The present study examines if differences in state-specific temperature changes exist in a healthy preterm cohort as another expression of brain dysmaturity. METHODS: Rectal and skin temperatures during sleep state transitions are reported in 59 asymptomatic post-conceptional age term infants, comparing 25 full term and 34 preterm infants. Three-hour 24-channel electroencephalogram (EEG)-sleep studies were recorded for each child. One of 4 sleep states were assigned for each of 7339 min, based on both cerebral and non-cerebral measures. For each study, average rectal and skin temperatures for each sleep state were calculated. Repeated measures MANOVA were performed using 4 explanatory variables, average skin and rectal temperatures and variance of rectal and skin temperatures, comparing preterm/fullterm status and 4 sleep states. RESULTS: Rectal temperature differences between neonatal cohorts during specific sleep states were noted: F=8.58, P<0.0001. Significant differences were noted for both average and variance of rectal temperatures during all 4 sleep states with higher temperatures in the preterm group. For all neonates, both skin and rectal temperature differences were also noted among sleep states (F=4.22, P<0.0004). Differences were specifically noted between two specific EEG segments, mixed frequency active sleep and tracé alternant quiet sleep (P<0.0004). CONCLUSIONS: In summary, significant differences in temperatures were noted across sleep state transitions for two neonatal cohorts, with higher average rectal temperatures in the preterm cohort. These findings highlight an altered measure of brain function during sleep in preterm infants affecting temperature regulation. This altered physiologic behavior reflects adaptation of the infant's brain function to conditions of prematurity which may contribute to vulnerabilities at older ages.

Body Temperature↗

Management options for preterm labour in Canada.

OBJECTIVES: (1) To determine the current use of treatment options for preterm labour and (2) to review the relative safety and efficacy of each class of tocolytic agent. METHODS: MEDLINE and the Cochrane Library were searched using the terms "preterm delivery," "preterm labour," and "tocolysis" alone, and in combination with the terms "betamimetics," "ritodrine," "magnesium sulfate," "calcium channel blockers," "nifedipine," "prostaglandin synthetase inhibitors," "indomethacin," "glyceryl trinitrate," "nitroglycerin," "oxytocin antagonists," and "atosiban." Randomized controlled trials (RCTs) that compared the effect of a tocolytic with a placebo or other tocolytic in women with preterm labour were selected. Trials were assessed according to Jadad's validated quality scale for assessing the quality of RCTs. Thirty two RCTs retrieved met the inclusion criteria. Information not evident from RCTs was sought from non-randomized clinical trials, cohort studies, case control studies, case series, and case reports. Data from the Canadian Survey on Tocolytic Use was obtained directly from the Society of Obstetricians and Gynaecologists of Canada (SOGC). RESULTS: The available evidence on the use of tocolytics to prolong pregnancy fails to show benefits in neonatal survival and reduced disability. This uncertainty of benefit makes the issue of fetal and maternal drug toxicity more important. There is great concern among SOGC members over the lack of effective and safe treatment options for the management of preterm labour. CONCLUSIONS: Further well-designed placebo-controlled trials are necessary to study the efficacy and safety of tocolytics in managing preterm labour.

Canada↗

Mechanisms of term and preterm birth.

Labour at term and preterm results from activation and then stimulation of the myometrium. Activation can occur through mechanical stretch of the uterus, and by endocrine pathways resulting from increased activity of the fetal hypothalamic-pituitary-adrenal axis. In women and in experimental animals, cortisol likely contributes to increased prostaglandin production in fetal tissues through up-regulation of the type 2 prostaglandin H2, synthase-2 (PGHS-2) and down-regulation of 15-OH prostaglandin dehydrogenase. Cortisol increases expression of prostaglandin dehydrogenase in the chorion by reversing the stimulatory effect of progesterone, and may represent "progesterone withdrawal" in the primate. By competing with progesterone inhibition, cortisol also increases expression of placental corticotropin-releasing hormone. Other agents, such as pro-inflammatory cytokines, similarly up-regulate PGHS-2 and decrease expression of prostaglandin dehydrogenase. Oxytocin, produced locally within the intrauterine tissues, is also thought to be involved in parturition, and there is a marked increase in oxytocin receptor expression at term. There are thus several mechanisms by which labour at term or preterm may be initiated. These different mechanisms need to be considered in the development of strategies for the detection and management of women in preterm labour. Ongoing studies are investigating the use of oxytocin receptor antagonists, PGHS-2 inhibitors, and nitric oxide to prevent or regulate preterm labour. The presence of fibronectin in vaginal secretions, and elevated maternal serum levels of corticotropin-releasing hormone, estrogens, and cytokines have been examined as possible markers of preterm labour. However, at the present time, we do not have the ability to accurately predict or diagnose preterm labour, nor do we have specific or efficient methods to inhibit labour once it has started.

Evidence-Based Medicine↗

Transient dystonias revisited: a comparative study of preterm and term children at 2 1/2 years of age.

Minor neurological dysfunctions (MND) have frequently been reported as an outcome of preterm birth. Behavioural and learning difficulties are a known feature, but coordination problems are especially described in preterm infants at later ages. All preterm infants in our study were born with a gestational age of <32 weeks and a birthweight of <1500 g. The aim of the study was to determine if in a normal clinical situation, children at risk for developing coordination problems could be detected by focusing particularly on their spontaneous, although elicited, motor performance. Forty-two children of 2 years 6 months of age were studied of whom 25 were 'low-risk' preterm and 17 were born at term. All children had been followed up since birth. In a structured, free-field situation the quality of body rotation, spontaneous reaching-out, and manipulation during parts of the Bayley Developmental Test were observed and videotaped. Body rotations were scored on a 2-point scale, and arm and hand functions on a 3-point scale. Most preterm infants showed non-optimal body rotations and borderline or non-optimal arm and hand functions in contrast to most term children. A clear connection was found between less optimal body rotations and poor arm and hand functions. Retrospectively, poor arm and hand functions at 2 years 6 months seemed to be related to those at 39 weeks. At the age of 39 weeks a clear relation had been found between poor postural control (many preterm infants could not sit independently) and earlier hyperextension of the trunk at 18 weeks and quality of arm-hand functions. In the present study at 2 years 6 months a correlation with the former hyperextension could no longer be found, but there was a significant relation between poor trunk rotation and arm and hand function and the earlier arm and hand functions at 39 weeks.

Arm↗

Altered pathways for auditory discrimination and recognition memory in preterm infants.

Preterm infants are at increased risk for cognitive disorders, including impairments in recognition memory. This study evaluated the effects of extreme prematurity on the neural pathway for auditory recognition memory using event-related potentials (ERPs), a neurophysiological technique widely used in cognitive neuroscience. ERPs were recorded at term postmenstrual age in 35 preterm infants born at less than 32 weeks' gestation (22 males, 13 females; mean birthweight ([BW] 1154g, SD 374g) with normal brain ultrasounds, compared with 40 healthy, term newborns (1 to 3 days of age; 20 males, 20 females; BW 3672g, SD 420g). Because infants must be able to detect and discriminate sounds before recognizing them, two paradigms were used to assess these functions. The first evaluated the detection and discrimination of speech sounds. The second tested recognition of the mother's voice compared with a stranger's. Results showed significantly different patterns of speech sound discrimination in preterm infants compared with term infants. No evidence of maternal voice recognition was elicited from the preterm infants. No specific patterns of auditory detection or discrimination were associated with patterns of recognition memory, suggesting that the function of multiple neural pathways may have been altered in this group of preterm infants. These results provide a functional corroboration of magnetic resonance imaging studies showing effects of prematurity on early brain development, even among preterm infants with normal cranial ultrasonography.

Auditory Cortex↗

Recall memory in the first three years of life: a longitudinal study of preterm and term children.

This report concerns the development and stability of recall memory at 12, 24, and 36 months of age in preterm (<1750 g birthweight) and term children from a prospective, longitudinal study. There were 56 preterm children (55.4% male; mean birthweight 1119.5 g [SD 279.2], range 551 to 1742 g; mean gestational age 29.7 weeks [SD 2.9], range 25 to 36 wks) and 126 term controls (51.6% male; mean birthweight 3453.8 g [SD 438.2], range 2500 to 4564 g; mean gestational age 40.2 weeks [SD 1.1], range 38 to 42 wks). Recall memory was assessed using an elicited imitation task in which children attempted to reproduce a sequence of actions 15 minutes after they were modeled by the examiner. Relative to term children, the preterm group performed poorly at all three ages: they reproduced fewer actions overall and fewer in the correct order. Lower birthweight and lengthier postnatal hospitalization were associated with poorer performance in preterm children at 24 and 36 months. Although performance improved considerably for both groups with age, there was no evidence of preterm 'catch-up': the deficits detected at 12 months did not diminish with age. Individual differences in recall were modestly stable from one year to the next, with cross-age correlations highest from 24 to 36 months (r=0.43 to 0.49). These results suggest that preterm children have deficits in recall memory that emerge by 12 months and persist into early childhood.

Child, Preschool↗

Prognostic value of flash visual evoked potentials in preterm infants.

This paper investigates the prognostic value of flash visual evoked potentials (VEPs) recorded in preterm infants at birth and at term age with respect to severe neurological outcome. Flash VEPs were recorded in 81 preterm infants at birth (i.e. <35 weeks' gestation) and repeated in 56 of these infants at term age. The preterm infants were assigned to either a healthy or at-risk subgroup based on clinical birth factors. Normal ranges of flash-VEP latencies, amplitudes, and number of components present were obtained from the subgroup of healthy preterm infants and from 68 term infants tested postnatally. The flash-VEP results of the entire preterm group were compared with the normal ranges and any abnormalities noted. Seven preterm infants in the at-risk group died, six of whom had abnormal flash VEPs before term age. Of the five infants from the at-risk group diagnosed with cerebral palsy (CP), three had abnormal flash VEPs before term age. Thus the sensitivity and specificity of the flash VEP with respect to survival was 86% and 89% respectively, and with respect to the development of CP was 60% and 92%. The abnormal features of the flash VEP associated with adverse outcomes comprised a delayed N3 component before term age and the absence of a positive component (P2) at term age.

Cerebral Palsy↗

Effects of timing of conception on birth weight and preterm delivery of natural family planning users.

OBJECTIVE: Various birth defects and untoward perinatal outcomes have been claimed to be associated with pregnancies conceived by gametes aged in vivo before fertilization. Thus, these outcomes were systematically assessed in pregnancies occurring in natural family planning (NFP) users. Our international multicenter cohort study of NFP pregnancies (n = 877) is by far the largest systematic study designed to assess pregnancy outcome and is of sufficient power to allow us to address the concern of low birth weight (< 2500 g) and preterm delivery (< 37 weeks gestation). STUDY DESIGN: In addition to gathering baseline medical data, evaluation was performed at 16 weeks, 32 weeks and at term. Data were collected in a systematic cohort fashion, verified by the five collaborating international recruiting centers, and analyzed by investigators in the US. Most recruiting center principal investigators are obstetrician-gynecologists and, if not, have integral relationships with such specialists. Standard criteria could thus be applied within and among centers. In our cohort, birth weight was recorded accurately at delivery. Almost all of the deliveries occurred in hospitals; thus, data should be quite reliable. Neonatal examination for anomalies was usually conducted immediately after delivery, when birth weight was recorded. RESULTS: Analysis of risk factors for low birth weight and preterm delivery showed that this population had a low risk profile. Low birth weight infants (< 2500 g) and preterm deliveries were increased among women with a history of either prior low birth weight or preeclampsia in the index pregnancy. However, mean birth weight was unaffected by the timing of conception vis à vis ovulation or pregnancy history. Mean birth weight for the 877 singleton NFP pregnancies was 3349.6 g. The risk of preterm delivery was increased among older women who drank alcohol, but there were no significant effects of timing of conception vis à vis ovulation on preterm delivery. Results held when analysis was stratified according to whether NFP was being used for contraception or to achieve pregnancy. CONCLUSIONS: Our data do not appear to show striking differences between 877 NFP pregnancies and the general obstetric population. The timing of conception vis à vis ovulation does not exert significant effects on the birth weight or preterm delivery of resulting pregnancies, a reassuring finding for NFP users.

Birth Weight↗

Chlamydia trachomatis seropositivity is associated both with stillbirth and preterm delivery.

The cause of stillbirth and preterm delivery is often unknown. We studied the prevalence of Chlamydia trachomatis antibodies in mothers with stillbirth and preterm labor. Serum specimens from 72 mothers with stillbirth after the 21st gestational week, and from 48 mothers with preterm delivery between gestational weeks 23 and 29, both from the greater Helsinki area, and cord blood from 96 consecutive liveborn deliveries at the Department of Obstetrics and Gynecology, the University of Helsinki, were studied for antibodies to C. trachomatis immunotypes CJHI, GFK and BED by microimmunofluorescence test. The prevalence of C. trachomatis antibodies was highest, 33.3%, in mothers with stillbirth, 18.8% in mothers with preterm delivery, and 10.4% in cord blood. The IgM seropositivity rate was high among mothers with preterm delivery (8.3%). We conclude that C. trachomatis IgG antibodies are frequently detected in sera from mothers with stillbirth, suggesting past infection, while mothers with preterm delivery often have serum IgM antibodies, suggesting of acute infection.

Acute Disease↗

Amplitude-integrated EEG in preterm infants: maturation of background pattern and amplitude voltage with postmenstrual age and gestational age.

OBJECTIVE: Amplitude-integrated electroencephalogram (aEEG) is a single channel EEG recorded from two parietal electrodes. The objective of this study was to test the hypothesis that aEEG maturation follows postmenstrual age (PMA) irrespective of gestational age (GA). METHODS: We recruited inborn infants with a GA <33 weeks and without evidence of neurologic anomaly. Serial aEEG recordings were assessed for: presence of continuous activity and mature sleep-wake cycling (SWC); low base voltage (V), that is, the lowest amplitude margin; high base V, that is, the most common amplitude margin; upper high V, that is, upper margin during highest activity; and span, that is, the difference between upper high and simultaneous high base V. Statistical analysis included logistic regression and repeated measures analysis of variance. RESULTS: We obtained 119 aEEG recordings in 31 preterm infants (GA 25 to 32 weeks; birth weight 600 to 1704 g, PMA 25 to 35 weeks). The frequency of mature SWC increased with PMA independent of GA, while the frequency of continuity increased with PMA and was higher in extremely preterm infants after correcting for PMA. Low base and high base V increased with PMA, while span and upper high V significantly decreased with PMA. In addition, high base V was higher in extremely preterm infants after correcting for PMA. CONCLUSIONS: In preterm infants aEEG matures predominantly with PMA. Our data suggest that some aspects of aEEG maturation are enhanced, rather than inhibited by extremely preterm birth. These data suggest that aEEG in preterm infants may need to be analyzed by comparing results with standards of similar PMA and GA.

Electroencephalography↗

A comparison of sonographic cervical parameters in predicting spontaneous preterm birth in high-risk singleton gestations.

OBJECTIVES: To assess the role of cervical sonography and to compare various sonographic cervical parameters in their ability to predict spontaneous preterm birth in high-risk singleton gestations. DESIGN: A prospective cohort of 469 high-risk gestations were longitudinally evaluated between 15 and 24 weeks' gestation on 1265 occasions with transvaginal cervical sonography and transfundal pressure. The cervical parameters obtained were funnel width and length, cervical length, percent funneling and cervical index. The information obtained was used for patient management. Restriction of physical activities was initiated at cervical lengths of < or = 2.5 cm with cerclage as an option for cervical lengths of < or = 2.0 cm. RESULTS: Receiver operating characteristic curve analyses showed that a cervical length of < or = 2.5 cm between 15 and 24 weeks' gestation was equal to the other sonographic cervical parameters in its ability to predict spontaneous preterm birth. The sensitivities for delivery at < 28, < 30, < 32 and < 34 weeks' gestation were 94%, 91%, 83% and 76%, respectively, while the negative predictive values were 99%, 99%, 98% and 96%, respectively. The placement of a cerclage did not influence the positive and negative predictive values. In comparison to women with other risk factors, cervical length was best in the prediction of preterm birth in women with a prior mid-trimester loss; an optimal cut-off of < or = 1.5 cm had sensitivities for delivery at < 28, < 30, < 32 and < 34 weeks' gestation of 100%, 100% 92% and 81%, respectively. The rate of preterm delivery at < 34 weeks' gestation increased dramatically when the cervical length was < or = 1.5 cm. Cervical length was the only independent variable that entered the logistic regression model for the prediction of preterm delivery at < 34 weeks' gestation. CONCLUSIONS: In high-risk singleton gestations a cervical length of < or = 2.5 cm was equal to other sonographic cervical parameters in its ability to predict spontaneous preterm birth and was better for the prediction of earlier forms of prematurity (at < 28 and < 30 weeks) than later forms (at < 32 and < 34 weeks). The optimal cervical lengths and their performance for predicting prematurity may be influenced by obstetric risk factors.

Adult↗

Axillary and tympanic membrane temperature recording in the preterm neonate: a comparative study.

STUDY AIMS: The aim of this study is to compare axillary temperature recordings with those of the tympanic membrane, in healthy preterm neonates, to ascertain whether there is any significant difference between the two recordings, in particular in relation to postnatal age, and if so to evaluate the clinical implications. RATIONALE: Immature thermoregulatory mechanisms, and small body size, mean preterm neonates are prone to temperature maintenance problems, and thermal stress is associated with increased morbidity and mortality. In order to ensure minimal handling, the ideal method of temperature recording would be rapid, painless and reproducible, and accurately reflect core temperature, whilst considering safety, comfort, ease of procedure and cost effectiveness. Recording of the tympanic membrane temperature is rapid and noninvasive, however, the accuracy of this method in preterm neonates has not been established. STUDY DESIGN: A comparative descriptive design was used, to describe differences in the recorded temperature in healthy preterm neonates, of gestational age of 27-37 weeks, related to temperature recording. METHOD: A second comparison was undertaken to establish difference in mean temperature recordings dependant on postnatal age of the baby in days. The sample included all babies fitting the selection criteria, admitted to the Neonatal Unit during the study period. Following approval by the local research ethics committee tympanic membrane and axillary temperatures were recorded consecutively for 7 days (n=154), using the Genius Model 3000A tympanic thermometer and a glass and mercury thermometer. RESULTS: A t-test demonstrated a statistically significant difference between the recordings (P < 0.05), tympanic membrane recordings being higher. However, analysis of variance indicated that this difference was not associated with postnatal age, and thus the presence of vernix in the auditory canal (P > 0.05). The findings were not, however, deemed clinically significant in that no change in care or treatment resulted from differences in temperature recordings. CONCLUSIONS: Whilst the findings cannot be applied to sick preterm neonate, it was concluded that tympanic membrane temperature recordings in healthy preterm neonates are safe, accurate, easy, and comfortable for the baby, and appropriate with this client group provided staff are trained in the technique.

Age Factors↗

Preterm infants' behavioural indicators of oxygen decline during bottle feeding.

BACKGROUND: During the time when preterm infants' oral feeding skills are developing they often experience physiological instability and need assistance from caregivers to maintain adequate oxygenation. Assisting infants to maintain optimal oxygenation during oral feeding requires an understanding of how they express and aim to self-regulate their oxygen status. AIM: The purpose of this study was to identify potential behavioural indicators of declining oxygenation during preterm infant early bottle-feeding. METHOD: The design was explorative. Data were collected from a secondary analysis of 20 videotapes of preterm infant bottle feedings which included concurrent oxygen saturation data. In this analysis infant behaviours and quality of breathing were coded and compared across three periods: high oxygen saturation, immediately preceding an oxygen desaturation event, and during an oxygen desaturation event. FINDINGS: Infants gave limited behavioural indicators of declining oxygenation. Immediately prior to a desaturation event, they had an increase in eye flutter and were typically sucking and apnoeic. During a desaturation event, they typically relaxed their arms/hands and stopped sucking. CONCLUSIONS: Reliance on preterm infant behavioural cues will be insufficient for detection of oxygen desaturation during oral feeding. Attention to changes in breath sounds and to the pattern of sucking are potentially important intervention strategies for the prevention of and appropriate response to oxygen decline during feeding. Sucking pauses may be a time when preterm infants aim to regulate their breathing pattern and thereby increase oxygenation. Interventions that focus on detection and minimization of apnoea during feeding, and which aim to protect infant sucking pauses, may reduce the number and severity of desaturation events preterm infants experience during bottle feeding.

Bottle Feeding↗

Gastric electrical activity and gastric emptying in term and preterm newborns.

The aims of this study were to evaluate the gastric electrical activity and gastric emptying in preterm and term newborns and to assess the development of gastric motility by comparing newborns of different gestational ages. The cutaneous electrogastrography and the ultrasonographic study of the gastric emptying were performed before and after milk formula in three groups of infants: 12 preterm newborns with a gestational age of 28-32 weeks, 11 preterm newborns with a gestational age of 32-36 weeks, and 10 full-term newborns with a gestational age of 36-40 weeks. All recording sessions were performed 1 week after infants had reached full enteral feeding. The percentage of normal slow waves was similar in the three groups but it was not predominant compared to tachygastria in the earliest premature infants (59.3% (12.7-92.3) vs. 29.6% (3.7-78.8); P < 0.05). In addition, a progressive increase in the normal slow wave percentage (59.3% (17.4-87.4), 60.9% (38.1-89.7), 77.8% (66.4-84.8); P < 0.05) was observed as gestation advanced. As regards gastric emptying parameters, the antral area was greater and T(1/2) was longer in the preterm newborns of 28-32 weeks than preterm newborns of 32-36 weeks and full-term newborns (fasting antral area: 0.96 cm2 (0.6-1.5), 0.63 cm2 (0.4-1.2), 0.55 cm2 (0.1-0.9) respectively, P < 0.05; T(1/2): 83.4 min (76.0-108.5), 70 min (57.5-89.5) and 71.8 min (54.9-81.2), respectively P < 0.05). The comparisons of gastric emptying curves made among the three groups showed a reduced antral dilatation in preterm newborns of 28-32 weeks compared to full-term newborns at 30 and 60 min after a meal. In conclusion, although enteral feeding is important for the development process of gastrointestinal motility, gastric electrical activity and gastric emptying show an intrinsic maturation depending on the gestational age.

Electromyography↗

Unintended pregnancy and preterm birth.

About one-third of all pregnancies that result in live births in the US are unintended. Despite the large number of these births, little is known about the outcomes of unintended pregnancies. The purpose of the current study was to evaluate the association between intendedness of pregnancy and preterm birth in a large prospective cohort of women who reported for prenatal care. Pregnant, black, low-income women were enrolled into this study at four hospital-based prenatal care clinics and one off-site hospital-affiliated prenatal clinic in Baltimore City. A self-administered questionnaire to assess demographic and psychosocial data was completed by each woman in the cohort at the time of enrolment in the study. The questionnaire contained an item to measure intendedness of the pregnancy. A total of 922 women comprised the final sample for analysis. For the analyses, intendedness was dichotomised as: intended (wanted now or sooner) vs. unintended (mistimed, unwanted or unsure). Overall, 13.7% of all births to women in the sample were preterm. In a logistic regression model, after controlling for potential confounding by clinical and behavioural predictors of preterm delivery, unintended pregnancy was significantly associated with preterm delivery (adjusted RR = 1.82, 95% confidence interval [1.08,3.08], P = 0.026). In this study of a cohort of urban, clinic-attending, low-income, pregnant black women, unintended pregnancy had a statistically significant association with preterm birth. After adjustment for behavioural and clinical risks, women with unintended pregnancies had almost twice the risk of a preterm delivery as women with intended pregnancies.

Adolescent↗

Preterm birth research: from disillusion to the search for new mechanisms.

No intervention has been shown to decrease the rate of preterm birth. There was thus a need for a new research agenda. The new emphasis is on social and biological mechanisms, including the impact on stress of racism and poverty, and gene-environment interactions. New markers are also under study, and pertain mostly to infection and inflammation. The impact on preterm birth of broad contextual factors, such as universal social protection, will need to be explored further. The recent trends toward increased rates of preterm births deserve much attention. New policies and interventions to decrease medically indicated preterm births should be urgently developed and evaluated. The failure to prevent preterm deliveries has been so disappointing that there is a risk that high rates of preterm births will be seen as unavoidable. The research programme launched by March of Dimes is a timely effort to foster new enthusiasm, to test new ideas and to generate new hypotheses.

Female↗

Testing a sociomedical model for preterm delivery.

The study purpose was to contribute to the development of a model for preterm birth that brings together social, psychosocial and biomedical factors. The three research questions were: (a) Which social and psychosocial factors influence the risk of preterm delivery? (b) Are the effects of social and psychosocial factors independent? (c) Do the biomedical factors identified and measured here explain the effect of social and psychosocial factors? The sample comprised 739 low-income black non-Hispanic women. Interviews were conducted after delivery, and medical records were abstracted. Nearly a quarter of the women delivered preterm (23.5%). Two social factors strongly predicted risk of preterm delivery: inadequacy of time and money for non-essentials. The effect of both was stronger than expected from each alone and was partially mediated by psychosocial factors. Several psychosocial factors also predicted preterm delivery risk but only stress and locus of control were independent predictors. With the inclusion of biomedical factors, stress (OR = 1.86, P = 0.005) and locus of control (OR = 1.75, P = 0.007) continued to be strongly associated with preterm delivery. The effect of inadequate resources for non-essentials was no longer significant, suggesting mediation. These strong effects of social and psychosocial factors should be examined in future studies.

Adolescent↗

Marital status, cohabitation, and risk of preterm birth in Europe: where births outside marriage are common and uncommon.

This article explores whether the impact of marital status on the risk of preterm birth varies in relation to marital practices in the population, defined by the proportion of out-of-marriage births. Data come from a case-control study of the determinants of preterm birth in 16 European countries (5456 cases and 8234 controls). There is a significantly elevated risk of preterm birth associated with both cohabitation (OR = 1.29 [1.08, 1.55]) and single motherhood (OR = 1.61 [1.26, 2.07]) for women living in countries where fewer than 20 of births occur outside marriage. In contrast, there is no excess risk associated with marital status when out-of-marriage births are more common. This overall result does not apply to all subgroups of preterm births: different patterns emerge for early preterm births and preterm births induced for medical reasons. It is important to consider social context in the analysis of individual risk factors.

Case-Control Studies↗