234 research outputs found
Influence of salinity and cadmium on the volume of Pacific herring eggs
Changes in total volume and volume of the yolk and perivitelline space of Pacific herring eggs were examined throughout incubation at 5°C in relation to salinity of the incubation medium (5, 20, 35â° S), and after exposure to cadmium (0.05â10 ppm Cd) at 20â° S. After fertilization and filling of the perivitelline space there was a decline in total egg volume in all salinities until 60â80 hr after fertilization. There followed a period of relative stability of total volume (100â240 hr), then a slow decline until hatching (240â618 hr). There was an inverse relation, between egg volume and salinity at all stages of egg development. Eggs transferred from 20â° to 5 or 35â° S, 87.4 hr after fertilization (90% blastodermal overgrowth of the yolk), showed only minor changes in total egg volume within the period of relative stability (100â240 hr). Prior to 80 hr, changes in egg volume appeared primarily to be simpleadjustments to prevailing osmotic and ionic conditions, modified, however, by presumed irreversible changes induced in the egg in relation to salinity experience at, and shortly after, fertilization. Subsequently, between 80â100 hr, egg volume appears to becomeregulated, commencing in the interval between late blastodermal overgrowth and blastopore closure. Yolk volume declined after fertilization, reached a minimum 40â60 hr after fertilization, increased to 100 hr, then decreased in the period of relative stability of total volume â presumably in relation to rapid growth of the embryo. In the latter period, yolk volume appeared resistant to change when eggs are transferred from 20 â° to 5 or 35 â° S, 87.4 hr, after fertilization. Volume of the perivitelline space reached a maximum after fertilization, then decreased until about 100 hr; between 100 and 240 hr it increased rapidly and was influenced only in a minor way by salinity changes in the incubation medium 87.4 hr after fertilization. Eggs exposed to cadmium in the interval between 1/2 and 30 hr after fertilization showed major reductions in total egg volume; total volume in the period of relative stability (100â240 hr) was much reduced and normal volume was not recovered after removal of such eggs to uncontaminated water at 30 hr
Challenges of a simplified opt-out consent process in a neonatal randomised controlled trial: a qualitative study of parentsâ and health professionalsâ views and experiences
Background: More effective recruitment strategies like alternative approaches to consent are needed to facilitate adequately powered trials. WithHolding Enteral feeds Around Transfusion (WHEAT) was a multicentre, randomised, pilot trial that compared withholding and continuing feeds around transfusion. The primary clinical outcome was necrotising enterocolitis (NEC). The trial used simplified opt-out consent with concise parent information and no consent form. Objective: To explore the views and experiences of parents and health professionals on the acceptability and feasibility of opt-out consent in randomised comparative effectiveness trials. Methods: A qualitative, descriptive interview-based study nested within a randomised trial. Semi-structured interview transcripts were analysed using inductive thematic analysis. Setting: Eleven neonatal units in England. Participants: Eleven parents and ten health professionals with experience of simplified consent. Results: Five themes emerged: âOpt-out consent operationalised as verbal opt-in consentâ, âOpt-out consent normalises participation while preserving parental choiceâ, âOpt-out consent as an ongoing process of informed choiceâ, âConsent without a consent formâ and âChoosing to opt out of a comparative effectiveness trialâ, with two subthemes: âWanting ânormal careââ and âA belief that feeding is betterâ. Conclusions: Introducing a novel form of consent proved challenging in practice. The principle of simplified, opt-out approach to consent was generally considered feasible and acceptable by health professionals for a neonatal comparative effectiveness trial. The priority for parents was having the right to decide about trial participation, and they did not see opt-out consent as undermining this. Describing a study as âopt-outâ can help to normalise participation and emphasise that parents can withdraw consent
Prevalence and risk factors for postnatal mental health problems in mothers of infants admitted to neonatal care: Analysis of two population-based surveys in England
Background Previous research suggests that mothers whose infants are admitted to neonatal units (NNU) experience higher rates of mental health problems compared to the general perinatal population. This study examined the prevalence and factors associated with postnatal depression, anxiety, post-traumatic stress (PTS), and comorbidity of these mental health problems for mothers of infants admitted to NNU, six months after childbirth. Methods This was a secondary analysis of two cross-sectional, population-based National Maternity Surveys in England in 2018 and 2020. Postnatal depression, anxiety, and PTS were assessed using standardised measures. Associations between sociodemographic, pregnancy- and birth-related factors and postnatal depression, anxiety, PTS, and comorbidity of these mental health problems were explored using modified Poisson regression and multinomial logistic regression. Results Eight thousand five hundred thirty-nine women were included in the analysis, of whom 935 were mothers of infants admitted to NNU. Prevalence of postnatal mental health problems among mothers of infants admitted to NNU was 23.7% (95%CI: 20.6â27.2) for depression, 16.0% (95%CI: 13.4â19.0) for anxiety, 14.6% (95%CI: 12.2â17.5) for PTS, 8.2% (95%CI: 6.5â10.3) for two comorbid mental health problems, and 7.5% (95%CI: 5.7â10.0) for three comorbid mental health problems six months after giving birth. These rates were consistently higher compared to mothers whose infants were not admitted to NNU (19.3% (95%CI: 18.3â20.4) for depression, 14.0% (95%CI: 13.1â15.0) for anxiety, 10.3% (95%CI: 9.5â11.1) for PTS, 8.5% (95%CI: 7.8â9.3) for two comorbid mental health problems, and 4.2% (95%CI: 3.6â4.8) for three comorbid mental health problems six months after giving birth. Among mothers of infants admitted to NNU (Nâ=â935), the strongest risk factors for mental health problems were having a long-term mental health problem and antenatal anxiety, while social support and satisfaction with birth were protective. Conclusions Prevalence of postnatal mental health problems was higher in mothers of infants admitted to NNU, compared to mothers of infants not admitted to NNU six months after giving birth. Experiencing previous mental health problems increased the risk of postnatal depression, anxiety, and PTS whereas social support and satisfaction with birth were protective. The findings highlight the importance of routine and repeated mental health assessments and ongoing support for mothers of infants admitted to NNU
Exploring the needs, concerns and knowledge of women diagnosed with gestational diabetes: A qualitative study
Very preterm infants engage in an intervention to train their control of attention: results from the feasibility study of the Attention Control Training (ACT) randomised trial
Background
Very premature birth (gestational age between 28 and 31 + 6âweeks) is associated with increased risk of cognitive delay and attention deficit disorder, which have been linked to anomalies in the development of executive functions (EFs) and their precursors. In particular, very preterm (VP) infants display anomalies in controlling attention and gathering task-relevant information. Early interventions that support attention control may be pivotal in providing a secure base for VP childrenâs later attainments. The Attention Control Training (ACT) is a cognitive training intervention that targets infantsâ abilities to select visual information according to varying task demands but had not been tested in VP infants. We conducted a feasibility study to test the processes we intend to use in a trial delivering the ACT to VP infants.
Methods and design
We tested recruitment and retention of VP infants and their families in a randomised trial, as well as acceptability and completion of baseline and outcome measures. To evaluate these aims, we used descriptive quantitative statistics and qualitative methods to analyse feedback from infantsâ caregivers. We also investigated the quality of eye-tracking data collected and indicators of infantsâ engagement in the training, using descriptive statistics.
Results
Twelve VP infants were recruited, and 10 (83%) completed the study. Participantsâ parents had high education attainment. The rate of completion of baseline and outcome measures was optimal. VP infants demonstrated engagement in the training, completing on average 84âmin of training over three visits, and displaying improved performance during this training. Eye-tracking data quality was moderate, but this did not interfere with infantsâ engagement in the training.
Discussion
The results suggest the ACT can be delivered to VP infants. However, challenges remain in recruitment of numerous and diverse samples. We discuss strategies to overcome these challenges informed by results of this study.
Trial registration
Registered Registration ID: NCT03896490. Retrospectively registered at Clinical Trials Protocol Registration and Results System (clinicaltrials.gov)
Effect of implementation of a preconception counselling resource for women with diabetes: A population based study
The impact of the Covid-19 pandemic on postnatal anxiety and posttraumatic stress: Analysis of two population-based national maternity surveys in England
Background
Few studies have evaluated postnatal anxiety and posttraumatic stress (PTS) before and during the Covid-19 pandemic using comparable data across time. We used data from two national maternity surveys in England to explore the impact of the pandemic on prevalence and risk factors for postnatal anxiety and PTS.
Methods
Analysis was conducted using population-based surveys carried out in 2018 (nâŻ=âŻ4509) and 2020 (nâŻ=âŻ4611). Weighted prevalence estimates for postnatal anxiety and PTS were compared across surveys. Adjusted risk ratios (aRR) were estimated for the association between risk factors and postnatal anxiety and PTS.
Findings
Prevalence of postnatal anxiety increased from 13.7âŻ% in 2018 to 15.1âŻ% in 2020 (+1.4âŻ%(95%CI:-0.4â3.1)). Prevalence of postnatal PTS increased from 9.7âŻ% in 2018 to 11.5âŻ% in 2020 (+1.8âŻ%(95%CI:0.3â3.4)), due to an increase in PTS related to birth trauma from 2.5âŻ% to 4.3âŻ% (+1.8âŻ%(95%CI:0.9â2.6); there was no increase in PTS related to non-birth trauma. Younger age (aRRâŻ=âŻ1.31â1.51), being born in the UK (aRRâŻ=âŻ1.29â1.59), long-term physical or mental health problem(s) (aRRâŻ=âŻ1.27â1.94), and antenatal anxiety (aRRâŻ=âŻ1.97â2.22) were associated with increased risk of postnatal anxiety and PTS before and during the pandemic, whereas higher satisfaction with birth (aRRâŻ=âŻ0.92â0.94) and social support (aRRâŻ=âŻ0.81â0.82) were associated with decreased risk.
Interpretation
Prevalence of PTS was significantly higher during the pandemic, compared to before the pandemic, due to an increase in PTS related to birth trauma. Prevalence of postnatal anxiety was not significantly higher during the pandemic. Risk factors for anxiety and PTS were similar before and during the pandemic
Maternal nutrition and fetal macrosomia in uncomplicated pregnancies: a prospective cohort study
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Prevalence and factors associated with postpartum posttraumatic stress in a population-based maternity survey in England
Background: Studies on prevalence and factors associated with postpartum posttraumatic stress (PTS) typically do not distinguish between PTS related to childbirth (PTS-C) and PTS related to other stressors (PTS-O). This study aimed to describe the prevalence, clinical characteristics, and factors associated with PTS-C and PTS-O in postpartum women.
Methods: The study was a cross-sectional population-based survey of 16,000 postpartum women, selected at random from birth registrations in England to receive a postal questionnaire, including the Primary Care Posttraumatic Stress Disorder Screen.
Results: Questionnaires were returned by 4,509 women. The median age was 32 years (IQR=29-36), 64% were married, 77% were UK-born, and 76% were White-British. Prevalence of PTS-C was 2.5% (95%CI:2.0-3.0) and prevalence of PTS-O was 6.8% (95%CI:6.0-7.8). Women with PTS-C were significantly more likely to report re-experiencing symptoms (Chi-Square=7.69,p<0.01). Factors associated with PTS-C were: higher level of deprivation, not having a health professional to talk to about sensitive issues during pregnancy, and the baby being admitted for neonatal intensive care. Factors associated with PTS-O were: age â€24 years, depression during pregnancy, and having a pregnancy affected by long-term health problems. Factors associated with both were: living without a partner, anxiety during pregnancy, pregnancy-specific health problems, and lower birth satisfaction.
Conclusions: PTS during the postpartum period is relatively common and, for many women, unrelated to childbirth. Increased awareness among health professionals of prevalence, clinical characteristics and factors associated with postpartum PTS-C and PTS-O will aid the development of appropriate management protocols to identify and support women during the perinatal period
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