SEARCH · PubMed Health

Results for “Postmenstruation”

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 361 records · Page 20Linked to original sources

PubMed2003

Integration of suck and swallow rhythms during feeding in preterm infants with and without bronchopulmonary dysplasia.

The aim of this study was to define quantitative measures for assessing the integration and maturation of suck and swallow rhythms in preterm infants as they relate to each other. Fourteen preterm infants (eight males, six females; gestational age range 26 to 32 weeks) with bronchopulmonary dysplasia (BPD) and an age-matched cohort of 20 infants (10 males, 10 females; gestational age range 26 to 33 weeks) without BPD were studied weekly from time of initiation of oral feeding using simultaneous recordings of nipple and pharyngeal pressure. The integration of suck and swallow rhythms was quantified by using the coefficient of variation (COV) of the suck-swallow dyad interval. Infants without BPD had a significant correlation between increasing postmenstrual age (PMA) and decreasing COV of the dyadic interval (increasing stabilization; r=0.45; p=0.008). In the non-BPD cohort 35 weeks or less PMA, the mean dyadic COV was 0.42 (SD 0.12) versus 0.34 (SD 0.09) in those more than 35 weeks PMA (p=0.039). In contrast, dyadic stability in infants with BPD was not correlated with PMA. Infants with BPD of more than 35 weeks PMA had less dyadic stability (0.45, SD 0.10) than did age-matched controls (p<0.001). Dyadic stability was also correlated with feeding efficiency in the non-BPD group (r=0.46;p=0.007) but not in the BPD cohort. Therefore, ontogeny of rhythmic suckle feeding can be described quantitatively in preterm infants, allowing comparison with at-risk populations. Infants with BPD do not follow predicted maturational patterns of suck-swallow rhythmic integration.

Analysis of Variance↗

PubMed2003

Cervical accelerometry in preterm infants with and without bronchopulmonary dysplasia.

Cervical accelerometry with digital signal processing (DSP) can identify signals that are consistently associated with swallowing during feeding of infants. It is shown that these signals, called initial discrete sounds (IDSs), become more uniform with advancing postmenstrual age (PMA) in healthy preterm infants. The objectives of this study were to determine if cervical accelerometry and DSP at a higher sample rate than previously used (22 kHz versus 16 kHz), in conjunction with a DSP software package that allows manipulation of the sound files, would improve the accuracy of the previously developed variance index (VI) method of analyzing accelerometric information. The modified VI method was then used to measure developmental differences in the IDS morphology of infants with and without bronchopulmonary dysplasia (BPD). VIs were calculated for 24 feeding studies of infants of between 32 and 39 weeks PMA: 12 studies on healthy preterm infants (n = 10: three males, seven females; mean gestational age [GA] 28.6 weeks, SD 0.4; mean birthweight [BW] 1080 g, SD 82; PMA mean 35.2 weeks, SD 0.6) and 12 studies on infants with BPD (n = 7: five males, two females; GA 27.1 weeks, SD 0.4; BW 911 g, SD 71; PMA 36.2 weeks, SD 0.6). There was a significant inverse correlation between VI and PMA for the healthy preterm group (r = 0.66, m = -2.31/week,p = 0.02). There was no significant correlation between VI and PMA for the BPD cohort. The VI of infants with BPD was significantly different from that of infants without BPD (p < 0.007, multiple regression analysis, interaction PMA x Group). Additionally, using our modified VI technique, 100% of swallows were found to have the expected IDS signals.

Analysis of Variance↗

PubMed2004

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↗

PubMed2005

Neonatal feeding performance as a predictor of neurodevelopmental outcome at 18 months.

This study aimed to determine whether neonatal feeding performance can predict the neurodevelopmental outcome of infants at 18 months of age. We measured the expression and sucking pressures of 65 infants (32 males and 33 females, mean gestational age 37.8 weeks [SD 0.5]; range 35.1 to 42.7 weeks and mean birthweight 2722g [SD 92]) with feeding problems and assessed their neurodevelopmental outcome at 18 months of age. Their diagnoses varied from mild asphyxia and transient tachypnea to Chiari malformation. A neurological examination was performed at 40 to 42 weeks postmenstrual age by means of an Amiel-Tison examination. Feeding performance at 1 and 2 weeks after initiation of oral feeding was divided into four classes: class 1, no suction and weak expression; class 2, arrhythmic alternation of expression/suction and weak pressures; class 3, rhythmic alternation, but weak pressures; and class 4, rhythmic alternation with normal pressures. Neurodevelopmental outcome was evaluated with the Bayley Scales of Infant Development-II and was divided into four categories: severe disability, moderate delay, minor delay, and normal. We examined the brain ultrasound on the day of feeding assessment, and compared the prognostic value of ultrasound and feeding performance. There was a significant correlation between feeding assessment and neurodevelopmental outcome at 18 months (p < 0.001). Improvements of feeding pattern at the second evaluation resulted in better neurodevelopmental outcome. The sensitivity and specificity of feeding assessment were higher than those of ultrasound assessment. Neonatal feeding performance is, therefore, of prognostic value in detecting future developmental problems.

Brain↗

PubMed2005

General movements in early infancy predict neuromotor development at 9 to 12 years of age.

Assessment of the quality of general movements (GMs) in early infancy is a powerful instrument to predict cerebral palsy (CP). The aim of the present study is to explore the value of GM assessment in predicting minor neurological dysfunction (MND) at 9 to 12 years of age. Two groups of infants were studied prospectively: 28 low-risk full-term infants (11 females, 17 males) and 24 high-risk infants, mostly born preterm (<37 weeks; 11 females, 13 males). In each group the quality of GMs (normal or abnormal) was assessed during two developmental periods: the age at which 'writhing' GMs occur (36 weeks' postmenstrual age to 7 weeks' postterm) and the age at which 'fidgety' GMs occur (8 to 17 weeks' postterm). Eight of 24 high-risk infants were diagnosed as having CP at 4 to 9 years of age. The remaining 44 children were followed-up at 9 to 12 years. In children without CP, quality of GMs at 'fidgety age' was related to neurological condition (normal, simple MND, complex MND) at follow-up (rho=0.46, p<0.01). Abnormal GMs at 'fidgety-GM age' showed a specific relationship to the development of coordination problems (chi2=6.1, p=0.01) and fine manipulative disability (Fisher, p<0.05) at 9 to 12 years. This finding supports the notion that the quality of GMs may provide information on the integrity of complex supraspinal circuitries.

Case-Control Studies↗

PubMed2006

Maturational changes in the rhythms, patterning, and coordination of respiration and swallow during feeding in preterm and term infants.

To study the coordination of respiration and swallow rhythms we assessed feeding episodes in 20 preterm infants (gestational age range at birth 26-33wks; postmenstrual age [PMA] range when studied 32-40wks) and 16 term infants studied on days 1 to 4 (PMA range 37-41wks) and at 1 month (PMA range 41-45wks). A pharyngeal pressure transducer documented swallows and a thoracoabdominal strain gauge recorded respiratory efforts. Coefficients of variation (COVs) of breath-breath (BR-BR) and swallow-breath (SW-BR) intervals during swallow runs, percentage of apneic swallows (at least three swallows without interposed breaths), and phase of respiration relative to swallowing efforts were analyzed. Percentage of apneic swallows decreased with increasing PMA (16.6% [SE 4.7] in preterm infants 35wks; 1.5% [SE 0.4] in term infants; p<0.001). Term infants had significantly lower BR-BR COV (0.405 [SE 0.016]) than preterm infants (0.641 [SE 0.052] at >35wks' PMA; 0.693 [SE 0.059] at <or=35wks' PMA). Phase relation between swallowing and respiration stabilized with increasing PMA, with decreased apnea, and a significant increase in percentage of swallows occurring at end-inspiration. These data indicate that unlike the stabilization of suck and suck-swallow rhythms, which occur before about 36 weeks' PMA, improvement in coordination of respiration and swallow begins later. Coordination of swallow-respiration and suck-swallow rhythms may be predictive of feeding, respiratory, and neurodevelopmental abnormalities.

Analysis of Variance↗

PubMed2006

Abnormalities in the coordination of respiration and swallow in preterm infants with bronchopulmonary dysplasia.

Individual rhythms of suck, swallow, and respiration are disrupted in preterm infants with bronchopulmonary dysplasia (BPD). Integration of respiration into suck-swallow efforts is critical for establishing coordinated suckle feeding. This study quantitatively assessed the coordination of respiration and swallow in infants with and without BPD. Thirty-four preterm infants of 26 to 33 weeks' gestational age were included: 14 participants with BPD (eight males, six females)and 20 comparison participants without BDP (10 males, 10 females). Participants were studied at postmenstrual age 32 to 40 weeks and postnatal age 2 to 12 weeks using digital recordings of pharyngeal pressure, nasal thermistor flow, and thoraco-abdominal plethysmography. The coefficients of variation (COV; standard deviation/mean) of the swallow-breath (SW-BR) and breath-breath (BR-BR) intervals during swallow runs, the percentage of 'apneic swallows' (runs of >or=3 swallows without interposed breaths), and phase relationships of respiration and swallow were used to quantify rhythmic coordination and integration of respiration into feeding episodes. Apneic swallows were significantly increased after 35 weeks in infants with BPD (mean 13.4% [SE 2.4]) compared with non-BDP infants (6.7% [SE 1.8]; p<0.05), as were SW-BR phase relationships involving apnea. The BPD cohort also had significantly higher SW-BR COV and BR-BR COV than non-BPD infants, indicating less rhythmic coordination of swallowing and respiration during feeding. Results emphasize the need for frequent rests and closer monitoring when feeding infants with respiratory compromise. Quantitative assessment of the underlying rhythms involved in feeding may be predictive of longer-term feeding and neurological problems.

Analysis of Variance↗

PubMed1997

In menstrual cycle stage a confounder in population-based psychiatric research?

BACKGROUND: It has been suggested that a failure to control for point in the menstrual cycle can lead to biased results in assessing psychiatric symptoms among women since state affects associated with premenstrual symptoms may lead to unreliability of symptom reporting as well as an artificial elevation of symptom ratings. We examine these hypotheses and the extent to which they can account for gender differences in symptom scale scores of demoralization and enervation. METHODS: The data are derived from an epidemiological study of Jews born in Israel between 1949 and 1958. The symptom scale scores of 2265 men and 1769 women (368 premenstrual, 458 menstruation and 943 postmenstrual) were compared regarding reliability, homogeneity and mean score. RESULTS: There were no differences among the menstrual groups, or between the men and women, in reliability of their responses as measured by the alpha coefficient and the coefficient of variation. There were no significant differences among the female groups on mean symptom scale score. The mean scale scores for each female group were significantly higher than the mean scores for men. CONCLUSIONS: Our results suggest that menstrual cycle stage does not influence the reliability of reporting, the variability of response or mean symptom levels. However, our conclusions may not apply to studies of drug effects or clinical studies of premenstrual dysphoria.

Adult↗

PubMed1975

An attributional approach to moods and the menstrual cycle.

Acceptance of an attribution pattern linking negative moods (depression, irritability) to the approach of menstruation and the likelihood of internal and external attributions were examined in a questionnaire study in which cycle phase (pre- versus postmenstrual), mood (positive versus negative), and environment (pleasant versus unpleasant) were varied. Subjects' rating indicated that (a) biology was judged important for explaining negative moods occurring premenstrually: (b) inconsistency between mood and environment produced more internal (personality) attributions, while consistency enhanced external attributions; and (c) emotionally expressive behavior was thought to reflect underlying personality dispositions despite extenuating situational factors (assumed personal causation). The theoretical relevance of the findings to a new conceptualization of premenstrual emotionality and to an attributional chain relating female self-concept and premenstrual tension is discussed.

Depression↗

PubMed1987

Retinopathy of prematurity in the United Kingdom.

Retinopathy of prematurity (ROP) continues to be a problem for some preterm infants who survive the neonatal period. We review changes which have occurred in the premature infant population and methods of ophthalmological examination since the last survey of ROP in the United Kingdom was conducted between 1951 and 1953. We have analysed data from a retrospective study, and from our current prospective survey of ROP in the East Midlands, to determine the age at onset of acute ROP. The results show that the ophthalmoscopically visible signs of ROP develop over a narrow postmenstrual age range suggesting that acute ROP occurs only after the retina and/or its vasculature have reached a certain stage of development.

England↗

PubMed1992

Light and the immature visual system.

Preterm neonates are cared for in an environment which is continuously and brightly lit, and is very different to that experienced at any other time of life. The amount of light reaching the neonatal eye is governed by two groups of factors. Physical factors include intensity, spectral characteristics and duration of light exposure. Physiological factors are: Frequency of eyelid opening, transmission of light through the closed eyelid, pupil reactivity and area, transmission by the ocular tissues and retinal surface area. Retinal irradiance declines with increasing postmenstrual age. Mechanisms by which light may affect the neonatal eye and clinical conditions in which light have been implicated are considered.

Dose-Response Relationship, Radiation↗

PubMed2005

Severe retinopathy of prematurity: longitudinal observation of disease and screening implications.

PURPOSE: To test the effectiveness of our Canadian retinopathy of prematurity (ROP) screening guidelines as applied to high-risk premature infants. STUDY DESIGN: Retrospective longitudinal cohort study. SUBJECTS: A total of 969 infants were examined longitudinally between 1991 and 2000 and 46 of these infants screened were treated for severe ROP. METHODS: Data from weekly ROP screening examination results were collected from a geographical area and analysed. RESULTS: The average incidence of severe ROP requiring treatment in the population of premature infants eligible for screening was 48.3 per 1000. In all, 46 infants were treated in this cohort. The mean gestational age (GA) was 25.5 weeks of age and the mean birth weight was 750 g. The mean chronological age (CA) and postmenstrual age (PMA) at the time of first screening was 36 days and 30.7 weeks, respectively. The first identification of any ROP in this group was at a mean CA 60 days and PMA of 34.1 weeks. The mean CA and PMA of the first observation of stage 3 were 74 days and 36.3 weeks. The mean CA and PMA at the time of treatment were 86 days and 37.7 week. CONCLUSIONS: Our observations and analysis indicate the following ROP screening recommendations: infants of 28 weeks of GA or less, infants with a GA between 28 weeks and 30 weeks should have a single 'spot examination' at approximately 37 weeks of PMA (or prior to discharge from hospital) to include possible outliers; infants born with a birth weight of 1250 g or less; initial screening examination should be at 31 weeks of PMA or 4 weeks of CA, whichever is later; in the presence of any active ROP, the infant should be followed every 1-2 weeks; and stage 3 should be followed at least every 7 days.

Age Factors↗

PubMed2002

Apnea at discharge and gastro-esophageal reflux in the preterm infant.

OBJECTIVE: To determine the relationship between respiratory patterns and acid gastro-esophageal reflux (g-e reflux) prior to discharge of the formerly preterm infant. STUDY DESIGN: Forty-five infants of <32 weeks' gestation were studied at an average postmenstrual age of 37.2 weeks (SD 3.5). Following informed parental consent, a 12-hour multichannel recording including esophageal pH was obtained. Apneas of greater than 10 seconds were recorded, as well as the occurrence of bradycardia or desaturation. RESULTS: Acid g-e reflux (pH <4.0) occurred at least once in all of the infants; prevalence was between <1% and 41% of the 12-hour record (median 4.6%, interquartile range 0.5% to 9%). The number of reflux episodes ranged from 1 to 143 (median 23). The number of apneas (>10 seconds duration) ranged from 0 to 71, median 6. There was no correlation between apnea frequency or severity and reflux frequency or duration. There was no difference in apnea frequencies between the 5 minutes after the start of a reflux episode and the 5 minutes prior to each episode. CONCLUSION: Acid g-e reflux in the formerly preterm infant at discharge is frequent and may be prolonged; there is no association between reflux and apnea.

Apnea↗

PubMedDate not supplied

Comparison of kangaroo care and standard care: behavioral organization, development, and temperament in healthy, low-birth-weight infants through 1 year.

OBJECTIVE: To determine whether Kangaroo Care (KC) for healthy, low-birth-weight (LBW) infants can promote better behavioral and developmental outcomes. STUDY DESIGN: In this historical control study, 26 infants in the KC group (GA: 34.3+/-2.5 weeks, BW: 1833.9+/-167.6 g) and 27 infants in the comparison group who received the standard medical-nursing care (34.6+/-2.3 weeks, 1850.9+/-156.7 g) were analyzed by the Neonatal Behavioral Assessment Scale (NBAS) at 40 weeks of postmenstrual age, the Bayley Scales of Infant Development and the Carey's Infant Temperament Questionnaire (ITQ) at 6 and 12 months corrected ages. RESULTS: KC infants had significantly higher NBAS scores in Orientation, State Regulation, and Supplementary items; lower Intensity scores and higher Mood scores at 6 months on the ITQ; and higher Bayley Scales score at 12 months. CONCLUSION: KC effectively promoted neonatal behavioral organization and enhanced developmental outcome over the first year of life for LBW infants.

Birth Weight↗

PubMed2003

The sy-fi study: a randomized prospective trial of synchronized intermittent mandatory ventilation versus a high-frequency flow interrupter in infants less than 1000 g.

OBJECTIVE: Mechanical ventilation has significantly decreased mortality for preterm infants with respiratory distress syndrome. However, the barotrauma associated with mechanical ventilation is responsible for the development of bronchopulmonary dysplasia (BPD) in 20% to 90% of these infants, depending on gestational age. Recent studies suggest that high-frequency ventilation is associated with better gas exchange and less barotrauma. The purpose of this study is to determine if high-frequency ventilation, using the flow interrupter, reduces the incidence of BPD in the ELBW infant. STUDY DESIGN: Parental consent was obtained prior to mechanical ventilation. Infants less than 1000 g without significant congenital anomalies were eligible for study entry. Infants were randomized, prior to the onset of mechanical ventilation, to receive either synchronized intermittent mandatory ventilation (SIMV) or high-frequency flow interruption. Both ventilator methods were obtained using the Infant Star Ventilator (Mallinckrodt, St. Louis, MO). Data were collected prospectively on all study entrants and analyzed using SigmaStat Software. RESULTS: Forty-six infants, from two centers, were enrolled in this study. There was no significant difference in the ventilator days or BPD, defined as oxygen requirement at 36 weeks postmenstrual age, between the high-frequency ventilation and SIMV groups.

Bronchopulmonary Dysplasia↗

PubMed2003

Brainstem maturation after antenatal steroids exposure in premature infants as evaluated by auditory brainstem-evoked response.

OBJECTIVE: Antenatal steroids result in fetal lung maturation, but may retard brain development. Auditory brainstem-evoked response (ABR) is a noninvasive assessment of brainstem maturation. The objective of this study was to determine if antenatal steroids affect brainstem maturation in infants </=32 weeks gestational age (GA). DESIGN/METHODS: Bilateral monaural ABR were performed within the first 24 hours using 80 db nHL unfiltered click stimuli at a repetition rate of 39.9/seconds. ABR waveforms were categorized into Response Types based on response replicability and peak identification. Absolute wave latencies and interpeak latencies were measured when applicable. Data were collected for antenatal steroid exposure, mode of delivery, chorioamnionitis in utero, exposure to illicit drugs, exposure to magnesium sulfate, mechanical ventilation and 5 minute Apgar score <5 minute. Infants with TORCH infections, unstable conditions, and chromosomal disorders were excluded. RESULTS: Of 186 infants studied, 130 received antenatal steroids. Data were analyzed in 2 week GA intervals. There was a significant difference (P<0.05) in race (29 vs 39% African-American), birth weight (1231 vs 1416 gm) and use of magnesium sulfate (60 vs 32%) among infants who did and did not receive antenatal steroids, respectively. There was no significant difference in the other parameters measured. Even after controlling for confounding variables, there was no difference between absolute wave latencies or interpeak latencies between groups at either 28 to 29 weeks' or 30 to 31 weeks' postmenstrual age. There was no significant difference in frequency distribution of ABR waveform Response Types between groups. CONCLUSIONS: Antenatal steroids have neither a deleterious nor beneficial effect on brainstem maturation as measured by ABR in infants at </=32 weeks GA.

Betamethasone↗

PubMed2004

Efficiency of breastfeeding as compared to bottle-feeding in very low birth weight (VLBW, <1.5 kg) infants.

OBJECTIVES: To examine feeding efficiency and correlates of feeding behaviors in breastfeeding as compared with bottle-feeding VLBW infants at 35 weeks corrected age (CA, postmenstrual plus chronologic age). STUDY DESIGN: In all, 105 singleton VLBW infants underwent a standardized feeding observation, of whom 35 were observed breastfeeding and 70 bottle-feeding. Intake, efficiency, and feeding behaviors were compared, and effects of infant and maternal factors were examined. RESULTS: Breastfeeding as compared with bottle-feeding infants took in smaller volumes (median 6.5 vs 30.5 ml, p<0.001), fed less efficiently (median 0.6 vs 2.2 ml/min, p<0.001), and spent less time with sucking bursts (mean 33 vs 55%, p<0.001). For breastfed infants, birth and neonatal factors and prior maternal breastfeeding experience were not associated with feeding efficiency or behaviors. CONCLUSION: Feeding performance of breastfeeding compared with bottle-feeding VLBW infants at 35 weeks CA is worrisome, and lactation intervention is needed for discharge planning.

Bottle Feeding↗

PubMed2005

Is the new definition of bronchopulmonary dysplasia more useful?

OBJECTIVE: To determine the incidence of bronchopulmonary dysplasia (BPD) in low birth weight (LBW) infants <1251 g managed with early bubble nasal continuous positive airway pressure (NCPAP) and a gentle ventilation strategy using the newly proposed definition for BPD and the previous definitions. METHODS: Needs for supplemental oxygen and positive pressure (positive pressure ventilation or NCPAP) during initial hospitalization were evaluated in 266 inborn LBW infants (birth weight <1251 g). The data were categorized in three weight groups, <751, 751 to 1000 and 1001 to 1250 g and the incidence of BPD was computed in survivors based on oxygen need at 28 days, 36 weeks postmenstrual age (PMA) and the new severity of BPD criteria, that is, mild BPD: need for supplemental oxygen > or =28 days, but not at 36 weeks PMA; moderate BPD: need for supplemental oxygen > or =28 days and <30% at 36 weeks PMA and severe BPD: need for supplemental oxygen > or =28 days, and >30% at 36 weeks PMA and/or positive pressure at 36 weeks PMA. Further, BPD-associated comorbidities and short-term outcome data during hospitalization were compared among the groups, defined by severity of BPD. RESULTS: Among LBW infants <1251 g, the incidences of BPD at 28 days and 36 weeks PMA were 21.1 and 7.4% respectively. Using the newly defined criteria, the incidences of mild, moderate and severe BPD were 13.5, 4.8 and 2.6%, respectively. In total, 64.6% of these infants had mild BPD and 70.8% weighed <751 g at birth. Associated comorbidities correlated significantly with grades of underlying pulmonary disease. Also, significantly longer hospital stay, discharge at a higher PMA and lower growth velocity was observed with increasing grades of BPD. CONCLUSIONS: The new system for grading the severity of BPD offers a better description of underlying pulmonary disease and correlates with the infant's maturity, growth and overall severity of illness. Whether it will have a role in predicting long-term outcome remains to be determined.

Age Factors↗