Psychological and physiological stress: impact on preterm birth

Psychosocial stress during pregnancy

OBJECTIVE

We sought to identify factors associated with high antenatal psychosocial stress and describe the course of psychosocial stress during pregnancy.

STUDY DESIGN

We performed a cross-sectional analysis of data from an ongoing registry. Study participants were 1522 women receiving prenatal care at a university obstetric clinic from January 2004 through March 2008. Multiple logistic regression identified factors associated with high stress as measured by the Prenatal Psychosocial Profile stress scale.

RESULTS

The majority of participants reported antenatal psychosocial stress (78% low-moderate, 6% high). Depression (odds ratios [OR], 9.6; 95% confidence interval [CI], 5.5-17.0), panic disorder (OR, 6.8; 95% CI, 2.9-16.2), drug use (OR, 3.8; 95% CI, 1.2-12.5), domestic violence (OR, 3.3; 95% CI, 1.4-8.3), and having > or =2 medical comorbidities (OR, 3.1; 95% CI, 1.8-5.5) were significantly associated with high psychosocial stress. For women who screened twice during pregnancy, mean stress scores declined during pregnancy (14.8 +/- 3.9 vs 14.2 +/- 3.8; P < .001).

CONCLUSION

Antenatal psychosocial stress is common, and high levels are associated with maternal factors known to contribute to poor pregnancy outcomes.

Integrated review of cytokines in maternal, cord, and newborn blood: part II-- associations with early infection and increased risk of neurologic damage in preterm infants

A growing body of literature supports the relationship of maternal inflammation with preterm birth and adverse neonatal outcomes, including infection and central nervous system (CNS) dysfunction. Mediators of inflammation, most notably proinflammatory cytokines, have been implicated as having an association with and perhaps playing a causal role in the pathogenesis, leading to adverse neonatal outcomes. Even though the association of cytokines with early adverse neonatal outcomes has been actively pursued as a line of research, there has been little integration of diverse findings across studies. Therefore, the purpose of this systematic review was to appraise and classify empirical evidence from human studies for the association of cytokine levels in blood (serum, plasma, or cells; maternal, cord, or neonatal) with two adverse early outcomes in preterm infants: early infection and increased risk of neurologic damage. The review revealed that the proinflammatory cytokines most frequently linked with sepsis are in the interleukin (IL) 1 family as well as tumor necrosis factor alpha (TNF-alpha) and IL-6. The proinflammatory cytokines most frequently linked to neurologic insult in the reviewed studies were IL-1beta, IL-6, and IL-8. In all cases where IL-1beta was studied, the levels were increased when there was neurologic insult. A better understanding of the relationship of these inflammatory substances with these adverse conditions is needed for the future development of maternal and neonatal biobehavioral nursing research.

The inextricable nature of mental and physical health: implications for integrative care

There is growing evidence that physical health problems are caused and exacerbated by psychological factors. Research indicates that psychological distress leads to physical disease through impairment of the neuroendocrine system and its interface with the body's immune response. However, the current health care delivery system splinters care into "psychiatric" and "physical" health silos. New approaches are needed to assure adequate professional knowledge of behavioral health at basic licensure, to increase the use of advanced practice psychiatric-mental health nurses in primary care settings, to identify and teach behavioral competencies for primary care providers, and to fund the design and evaluation of integrative models of care.

Stress and preterm labor and birth in Black women

OBJECTIVE

To examine (a) 3 commonly used measures of stress during pregnancy, (b) changes in stress over time to determine when stress is highest, and (c) whether any of the stress measures predict who will deliver preterm in pregnant Black women.

DESIGN

Prospective descriptive study.

SETTING

Perinatal evaluation center and outpatient clinics of a teaching hospital in the northeast.

PARTICIPANTS

Fifty-nine Black women: 39 were recruited in preterm labor from a Perinatal Evaluation Center, and 20 experiencing healthy pregnancies were recruited from the prenatal clinic.

MEASURES

Stress was measured using 2 paper and pencil tests (the Prenatal Distress Questionnaire and the Perceived Stress Scale) and corticotropin-releasing hormone.

RESULTS

There was not a high correlation between stress measures. Stress at 28 weeks as measured by Prenatal Distress Questionnaire and Perceived Stress Scale was at its highest, but corticotropin-releasing hormone increased to 32 weeks and then decreased.

CONCLUSIONS

Perceived stress, prenatal distress, and corticotropin-releasing hormone do not all appear to be measuring the same phenomenon. Screening for stress in Black women at 28 weeks requires further research as perceived stress levels in Black women experiencing preterm labor around 28 weeks differentiated women who delivered preterm infants from Black women who delivered at term.

Physical and mental health outcomes of prenatal maternal stress in human and animal studies: a review of recent evidence

Prenatal maternal stress (PNMS) has been linked with adverse health outcomes in the offspring through experimental studies using animal models and epidemiological studies of human populations. The purpose of this review article is to establish a parallel between animal and human studies, while focusing on methodological issues and gaps in knowledge. The review examines the quality of recent evidence for prevailing PNMS theoretical models, namely the biopsychosocial model for adverse pregnancy outcomes and the fetal programming model for chronic diseases. The investigators used PubMed (2000-06) to identify recently published original articles in the English language literature. A total of 103 (60 human and 43 animal) studies were examined. Most human studies originated from developed countries, thus limiting generalisability to developing nations. Most animal studies were conducted on non-primates, rendering extrapolation of findings to pregnant women less straightforward. PNMS definition and measurement were heterogeneous across studies examining similar research questions, thus precluding the conduct of meta-analyses. In human studies, physical health outcomes were often restricted to birth complications while mental health outcomes included postnatal developmental disorders and psychiatric conditions in children, adolescents and adults. Diverse health outcomes were considered in animal studies, some being useful models for depression, schizophrenia or attention deficit hyperactivity disorder in human populations. The overall evidence is consistent with independent effects of PNMS on perinatal and postnatal outcomes. Intervention studies and large population-based cohort studies combining repeated multi-dimensional and standardised PNMS measurements with biomarkers of stress are needed to further understand PNMS aetiology and pathophysiology in human populations.

Depression, anxiety and influencing factors in pregnancy: a study in a Turkish population

OBJECTIVES

to determine the prevalence of depression in pregnancy and the factors that influence the development of depression and anxiety in pregnancy in a Turkish population.

DESIGN

a descriptive, correlational study.

SETTING

a public hospital in Ankara Province Centre, Ankara, Turkey.

PARTICIPANTS

1,039 pregnant women selected using a convenience sampling method.

FINDINGS

27.9% (n=290) of the 1,039 women were found to be experiencing depression at a level requiring treatment. In a stepwise multiple linear regression analysis model developed for depression and anxiety, the following were found to be statistically significant factors influencing the experience of both depression and anxiety: perceived social support; recent experience of marital or emotional problems during and before this pregnancy; recent experience of life stress; having a negative self-perception; experience of physical violence; and experience of physical problems during pregnancy. Statistically significant factors influencing depression were marital dissatisfaction, being a housewife, having an unwanted pregnancy, and having a formal marriage. The correlation between total anxiety and depression scores was at a medium level (Pearson correlation=0.592).

KEY CONCLUSIONS

many factors influenced the development of depression and anxiety in pregnancy, and a positive correlation was found between depression and anxiety. Midwives and nurses can evaluate pregnant women for these risk factors, and arrange for additional follow-up. They can also offer preventive care and, when necessary, assist with early diagnosis and treatment to improve the health of mothers and babies.

Mood states and milk output in lactating mothers of preterm and term infants

The purpose of this study is to compare psychological distress via both negative and positive mood states between 2 different groups of lactating mothers during the first 6 weeks postpartum with a large sample. Mood states were measured using the Multiple Affect Adjective Check List-Revised by a convenience sample of newly delivered mothers from 4 tertiary care units in Illinois. Preterm mothers' negative mood states of anxiety, depression, hostility, and dysphoria were significantly greater than those reported for term mothers. For the positive mood states of positive affect and PASS (positive affect + sensation seeking), preterm mothers had significantly lower scores than term mothers; there were no differences for the positive mood state, Sensation Seeking. Maternal perceived mood states had no apparent effect upon lactation as measured by milk volume produced. Further study is warranted to determine what factors influence milk output in mothers of preterm and term infants who are at risk for lactation failure.

Risk factors for pre-term birth in Iraq: a case-control study

Background

Preterm birth (PTB)is a major clinical problem associated with perinatal mortality and morbidity. The aim of the present study is to identify risk factors associated with PTB in Mosul, Iraq.

Methods

A case-control study was conducted in Mosul, Iraq, from 1^st September, 2003 to 28^th February, 2004.

Results

A total of 200 cases of PTB and 200 controls of full-term births were screened and enrolled in the study. Forward logistic regression analysis was used in the analysis. Several significant risk associations between PTB and the following risk factors were identified: poor diet (OR = 4.33), heavy manual work (OR = 1.70), caring for domestic animals (OR = 5.06), urinary tract infection (OR = 2.85), anxiety (OR = 2.16), cervical incompetence (OR = 4.74), multiple pregnancies (OR = 7.51), direct trauma to abdomen (OR = 3.76) and abortion (OR = 6.36).

Conclusion

The main determinants of PTB in Iraq were low socio-economic status and factors associated with it, such as heavy manual work and caring for domestic animals, in addition to urinary tract infections and poor obstetric history.

Stress model for research into preterm delivery among black women

The disparity between black and white infant mortality rates increased over the last decade, despite overall improvement in infant survival. Because most black infant deaths are related to preterm delivery, the discovery of the cause of premature birth in general and excess premature birth for black infants in particular is of paramount importance for reproductive health research. Substantial theoretic support exists for maternal stress as a risk factor for preterm birth. Traumatic events early in life may sensitize the adult to contemporary stresses and increase her vulnerability to stress-induced neuroendocrine or infection/inflammatory pathways to early parturition. In addition, an individual may prematurely age as a result of cumulative stress or a major traumatic event. This "stress age," which is synonymous with the concept of weathering and similar to the concept of allostatic load, may affect parturition through chronic conditions (such as hypertension) and in poorly understood pathophysiologic mechanisms that are related to increased chronologic age. One potential measure of stress age is maternal serum dehydroepiandrosterone sulfate. Maternal stress is a potential explanatory factor for excess preterm delivery among black women because of their exposure to racism-associated stress. However, few studies have addressed this question, and results are mixed. Future etiologic research must take into account the complexities of the measurement of stress age and past and current exposures to stress, which includes internalized racism and interpersonal racism.

Measuring stress responses in postpartum mothers: perspectives from studies in human and animal populations

Reduced hypothalamic-pituitary-adrenal (HPA) responses to stress during the last week of pregnancy and lactation have been consistently observed in rat studies. Several contributing factors have been proposed for this phenomenon in lactation, including the suckling stimulus from the pups, hormones (oxytocin and prolactin) and opioids, a decrease in the ability of noradrenaline to potentiate hypothalamic responses and changes in pituitary responsiveness to ACTH secretagogues (AVP and CRF). In contrast to this vast literature using the rat model, only few studies have addressed this issue in the human population. The consensus is that women engaging in breastfeeding activities exhibit reduced anxiety, although the reductions in neuroendocrine and autonomic responses to stressors are variable, in part because of the different nature of the stressors used. Further work is required to investigate how additional factors, such as maternal parity or emotional salience of the stressor can affect stress responsiveness in postpartum women. Here, we review first the findings regarding stress responsiveness during lactation in both rat and human studies, and then discuss potential research avenues and methodological issues that could be the lead to future research protocols in human subjects. Knowing the reciprocal relationship in the mother-infant dyad, it is clear that investigation of the mechanisms regulating stress responses and mental health in postpartum mothers can only be beneficial to the development of the infant.