Literature ReviewThis literature review will consider four peer-reviewed research papers concerned with the causality of depression in pregnant women and the effects of maternal depression on the psychological and physical well-being of their infants. The research will differentiate between quantitative and qualitative data and consider the appropriate methodology used to gather the data. I will examine how the research was undertaken and completed and whether the methodology was valid and reliable. I will also consider ethical issues and any concerns regarding the safeguarding of patient confidentiality. 1. ‘Does mothers’ postnatal depression influence the development of imitation?’ In this study, the authors hypothesise that postnatal depression (PND) may interfere with infants’ ‘imitation’, which is an early learning ability that features in early mother and infant interaction and is linked to memory, causal understanding and joint attention. This study demonstrated a mixed methodology as the quantitative data was sufficient to present a nationally representative sample of British first-time mothers and their infants and to examine whether there is a correlation between PND and a reduction in imitation. The qualitative data involved observation, interviews and questionnaires and allowed the researchers to investigate aspects of sociodemographic adversity and to find out whether there were causal elements of depression during pregnancy or prior to conception. Methodology 332 first-time mothers represented the entire range of socioeconomic categories in the UK, so the final sample was nationally representative, equivalent to the most recent UK national cohort study. 301 parents were interviewed and observed with their children. One parent was interviewed by phone, eight filled in questionnaires. Six families abandoned the study, four failed to keep appointments, eight could not be traced within the time frame, and four could not be assessed because of illness or for other reasons. 253 infants were given 2 imitation tasks of differing complexity (handling a doorknocker, a light or a spring; banging on a box; and one other task), of which 174 (68.8%) imitated an action at least once. The children of women with PND were less likely than others to imitate the actions. Only 10 (48%) of the infants whose mothers had been depressed after giving birth imitated the model at least once, whereas 160 (70%) mimicked at least one modelled action. Only completed tasks were recorded, which could possibly make this research less reliable, but there was a small p-value which would indicate that the study suggested that the likelihood of PND influencing imitation tasks was greater than simple chance. The ethical considerations in this study are that informed consent was needed in order to undertake experiments on children and there were issues of confidentiality?with mothers who have PND. That parents were given the right to withdraw from the programme demonstrates that correct ethical considerations were implemented. The potential benefits of being able to associate learning difficulties in children of mothers with PND and thereby supporting those children so that they are treated with justice, respect and equality within society outweigh any other ethical considerations. The study also demonstrates the power of social modelling as children imitate a ‘power’ role model. Those children who imitated more than once seem to get a positive reinforcement from their role model and if the parent repeats this action their infants understand that what they have done is a good action.?  The limitations of this study might be that the cohort size is not large enough to extrapolate into the wider population. Moreover, the imitation exercises were perhaps too brief to be reliable or effective, especially because observation was limited. Perhaps some of the children showed poor imitation because the parents had not had the experiment explained to them clearly enough. The Hawthorne effect could also be taken into account as both parent and child might have been conscious that they were being observed. However, knowledge of the effects on learning of PND should inform health professionals in postnatal care, which could lead to further studies and possible intervention strategies.  2. ‘Mechanisms of resilience in children of mothers who self-report with depressive symptoms in the first postnatal year.’ The second study investigated whether PND symptoms might increase the possibility of adverse effects on child. It tried to discover the mechanism of resilience in children exposed to PND symptoms. Methodology Data was taken from a large-scale prospective cohort study. The methodology of this research is a qualitative review as mothers were given questionnaires during pregnancy and the child’s first two years asking the mothers their views of parenting and how they judged the development of their child. The Edinburgh Postnatal Depression Scale was completed postnatally at 8 months and the Strengths and Difficulties Questionnaire at 11. Children of mothers with PND who scored above the median of children of mothers who did not report PND were seen as resilient. Exploratory factor analysis was used with the statistical data. It has been recorded that modelling condition (Albert Bandura) could affect the results:  belief in one’s ability and efficacy to control one’s life and actions might be a factor in non-optimal child development. There were 14,541 pregnancies and 13,988 children alive aged 1. There were 10,923 pregnant mothers with pre-natal depression. Those mothers excluded were multiple births and mothers of children who died (4,423). 1,009 children in total were exposed to maternal PND. Positive parenting behaviours and interactions with their child were associated with better verbal skills and fewer behavioural difficulties at a younger age in the study of the ALSPAC cohort (aged 7 compared with 11 in the study under consideration). This confirms speculations suggesting that positive maternal parenting characteristics may have important protective effects in high-risk populations, serving to neutralise some of the effects of the risks encountered. One finding of the study was that children who at 15 months show greater ability in communicating non-verbally are more likely to be resilient at 11. Because of the way in which data was collected it is not certain if the non-verbal communication shown by the children at the age of 2 produced warm responses in their mothers. However, it might be that such non-verbal communication could have positive chains of responses from the mother, which in turn brought about resilience. Within the paper it is stated that ethical approval for the study was obtained from the ALSPAC ethics committee and the local research ethics committee. Parents were given the right to withdraw from receiving the questionnaire by post. However, again the Hawthorne effect might have made an impact and made data less reliable. There was only one method used to gather data, which might have made the information unreliable, as there may not have been enough evidence. Moreover, a numerical description rather than a detailed narrative generally provides less elaborate accounts of human perception. It has been suggested that there were difficulties within the questionnaires as some were completed at different points in the survey, reflecting in a different way on the development of the children. A quantitative approach has shown that findings can give evidence either to support or contradict a hypothesis. What is clear is that it might contradict the hypothesis as there is a low rate of reliance in children. Nonetheless, the growing knowledge on resilience may be vital in guiding social policies for the promotion of well-being and positive adaptation across communities. Early interventions could help improve the long-term outcomes for children and possibly interrupt the intergenerational transmission risk of depression. By assessing those things that have contributed to the development of resilience in children who have been exposed to PND there is a better understanding of those aspects of a child’s early environment that may help support them to withstand the effects of the symptoms of PND.  3. ‘Influence of prenatal maternal stress maternal plasma cortisol and cortisol in atomic fluid on both outcomes and child temperament at three months.’ This study aimed to investigate relationships between indicators of maternal pre-natal stress, infant birth outcomes and early temperament. Associations and possible pathways between cortisol plasma concentrations and maternal pre-natal stress, cortisol in the amniotic fluid, birth outcomes and infant temperament at 3 months were examined. MethodologyThe participants in this study took part in a longitudinal project into the effects of pre-natal hormones on development in children. Pregnant women who had been referred for amniocentesis after pre-natal diagnostic screening were asked to join the study. Candidates were contacted by letter and 185 women agreed to take part. Healthy singleton pregnancies were signed up. The final sample numbered 158 pregnant women (with 78 boy and 80 girl foetuses).Quantitative data was obtained from questionnaires during the month before the amniocentesis. Mothers were asked to assess their levels of stress on a 4-point scale, ranging from ‘not at all’ to ‘all the time’. They also filled in a pregnancy-related anxieties’ questionnaire (fear of giving birth to a physically or mentally handicapped child, etc.). 15 minutes before amniocentesis mothers were again asked to quantify stress. In terms of quantitative data, cortisol in amniotic fluid was determined by radioimmunoassay. Infant gestational age and infant birth weight were used as perinatal outcomes and infant temperament was evaluated at 3 months.Maternal self-reports of perceived stress, fear of giving birth and anxiety at the time of the amniotic puncture were not associated with either maternal or foetal cortisol levels. Of course, cortisol concentrations collected in this study partly reflect the stress of the amniocentesis procedure. As hypothesised, maternal cortisol and amniotic fluid cortisol were positively linked. The finding of a positive association further supports the theory that amniotic fluid cortisol concentrations are influenced by maternal HPA-axis functioning and are not fully protected by 11 ?-HSD. An additional aim of this study was to investigate the influence of pre-natal factors on birth outcome and child temperament. Perceived stress during pregnancy was found to correlate with troubled temperament at 3 months. The main interest, however, was in whether stress assessed through maternal plasma and amniotic fluid cortisol affected birth outcomes and temperament. No relation was found between maternal cortisol and any infant outcome measures. There was, however, correlation between amniotic fluid cortisol and infant gestational age and birthweight. Greater levels of cortisol in the amniotic fluid correlated with shorter gestational age and lower birth weight. The study showed that maternal behaviour can be an important moderator of the effects of pre-natal factors on later outcome.Ethical guidelines were followed. Mothers were informed of the dangers inherent in amniocentesis, especially in older women.This is one of the few studies to assess at the same time the role of maternal and amniotic fluid cortisol on birth outcomes and infant emotional development. The results suggest that foetal cortisol may be an important predictor of infant outcomes and help show how pre-natal maternal stress can affect infant mental well-being. 4. ‘Effects of pre-natal depressive symptoms on maternal and infant cortisol reactivity.’  The literature suggests that pre-natal depression is associated with adverse offspring outcomes. Current thinking accounting for mood-associated effects implicates alterations of the maternal and foetal hypothalamic-pituitary adrenal axes. Recent work has led to the idea that PND could be linked with a failure to attenuate cortisol reactivity during early pregnancy. This study looked at whether this effect continues later on in pregnancy. The study also tested whether pre-natal cortisol reactivity can be measured against infant cortisol reactivity. Methodology The study investigated 103 women in the second and third trimesters of pregnancy. The respondents were asked to fill in a questionnaire asking their demographics and their mood levels. They were then asked to watch a 6-minute film of distressed babies. Saliva samples were collected five times during the test session; 2 samples were taken before the film; a third sample was taken immediately after the film; fourth and fifth samples were taken 10 and 20 minutes after the film. Maternal depressive symptoms were self-reported via the questionnaires. Postnatal mood symptoms were further assessed by visits at the participants’ homes and saliva samples were also taken from their infants by the mothers. The methodology uses quantitative data as the researchers wanted to measure the amount of cortisol in the mothers’ saliva. Qualitative data regarding depressive symptoms was taken via questionnaire. One aspect of the study that might render the findings less than universal is that the participants were ‘primarily Caucasian … highly educated, had a mean age of 31’ and all were pregnant for the first time. The researchers admit that ‘the participants were drawn from a low-risk community sample and levels of maternal prenatal depression were relatively low.’ Contrary to the researchers’ initial hypotheses, symptoms of depression were not associated with maternal hyper-cortisol secretion in response to the infant distress stimulus. Cortisol reactivity in the mothers did not match infant cortisol reactivity. The ethical considerations were not clear in this study. The showing of the ‘short film depicting distressed young infants, all under the age of 6 months’ might arguably have stimulated and increased cortisol levels and could be in conflict with the non-maleficence principle in that it might effect levels of distress and anxiety in the participants.?It is worrying that the researchers reported that ‘the infant distress video may not have been a sufficiently potent stressor to induce a cortisol stress response in this group of pregnant women, although participants did report increases in state anxiety following the film.’  In conclusion, it is clear from these literature reviews that the topic of depression in pregnant women and the effects of maternal depression on the psychological and physical well-being of their infants is a field that demands a great amount of quantitative data and that knowledge of the effects on learning of PND should inform health professionals in postnatal care, which could lead to further studies and possible intervention strategies. Qualitative data is problematic given that studies are often self-selective. In the third study, the lack of association between self-reported and physiological assessments of stress highlighted the challenges of conducting research on stress in pregnancy and the need to combine subjective and more objective assessments to gain a more complete understanding of maternal stress. Moreover, the studies here are arguably not as diverse in terms of sociodemographics as they might be. Ethically, all studies undertaken were bound by national and local guidelines and there were no declared conflicts of interest. Women with depression need to be treated perhaps more carefully than participants in studies where mental health well-being is not an issue. Also, infants are unable to give informed consent and their human rights must be taken into account. My one concern was regarding the use of film of distressed infants, first on the well-being of the babies showing distress and second on the psychological well-being of the women who were shown the film. Nevertheless, it is clear that there is importance in there being more research to monitor and enhance cognitive and motor skills in infants and to support the psychological well-being of women pre- and postpartum.