Stress-related eating in pregnancy? An RCT examining links between prenatal stress and food choices.

BACKGROUND: Diet quality during pregnancy is important for maternal health and offspring development. However, national dietary recommendations are not always met. A potential barrier for healthy food choices might be the experience of stress. Previous literature in non-pregnant populations suggests a negative effect of acute stress on diet quality. This preregistered study is the first to test whether an acute stressor leads to unhealthy food choices in pregnancy and examine the moderating role of stress, depressive and anxiety complaints in daily life. METHOD: Pregnant women (N = 110, 3rd trimester) completed online self-reported surveys measuring stress, depressive and anxiety complaints in daily life. Hereafter, participants were invited for a laboratory visit, in which they were exposed to the Trier Social Stress Test or a control task. After this manipulation, self-reported and actual food choices and food intake were assessed. At the end of the visit, a hair sample was collected. Throughout the visit, visual analogue scales on negative affect were completed and saliva samples were collected. RESULTS: The stress group experienced significantly more psychological stress than the control group during the experimental manipulation. Main regression analyses showed that the acute laboratory stressor did not cause unhealthy food choices in the third trimester of pregnancy. In fact, the stress group chose fewer unhealthy foods and consumed fewer kilocalories compared to the control group. Additionally, the findings point at a moderating role of depressive and stress complaints in daily life on food choices within the control group: higher scores were related to more unhealthy food choices and more kilocalories consumed. DISCUSSION: As this was the first study to test the effect of an acute stressor on food choices in pregnant women, more research is needed to obtain a better understanding of stress-related eating in pregnancy. This knowledge may inform future interventions to support pregnant women in improving their diet quality.

Urbanicity, hypothalamic-pituitary-adrenal axis functioning, and behavioral and emotional problems in children: a path analysis.

BACKGROUND: Urbanization is steadily increasing worldwide. Previous research indicated a higher incidence of mental health problems in more urban areas, however, very little is known regarding potential mechanisms underlying this association. We examined whether urbanicity was associated with mental health problems in children directly, and indirectly via hypothalamic-pituitary-adrenal (HPA)-axis functioning. METHODS: Utilizing data from two independent samples of children we examined the effects of current urbanicity (n = 306, ages seven to 12 years) and early childhood urbanicity (n = 141, followed from birth through age 7 years). Children's mothers reported on their mental health problems and their family's socioeconomic status. Salivary cortisol samples were collected during a psychosocial stress procedure to assess HPA axis reactivity to stress, and at home to assess basal HPA axis functioning. Neighborhood-level urbanicity and socioeconomic conditions were extracted from Statistics Netherlands. Path models were estimated using a bootstrapping procedure to detect indirect effects. RESULTS: We found no evidence for a direct effect of urbanicity on mental health problems, nor were there indirect effects of urbanicity through HPA axis functioning. Furthermore, we did not find evidence for an effect of urbanicity on HPA axis functioning or effects of HPA axis functioning on mental health problems. CONCLUSIONS: Possibly, the effects of urbanicity on HPA axis functioning and mental health do not manifest until adolescence. An alternative explanation is a buffering effect of high family socioeconomic status as the majority of children were from families with an average or high socioeconomic status. Further studies remain necessary to conclude that urbanicity does not affect children's mental health via HPA axis functioning.

Association between Psychosocial Stress and Fecal Microbiota in Pregnant Women.

Maternal prenatal psychosocial stress is associated with altered child emotional and behavioral development. One potential underlying mechanism is that prenatal psychosocial stress affects child outcomes via the mother's, and in turn the child's, intestinal microbiota. This study investigates the first step of this mechanism: the relation between psychosocial stress and fecal microbiota in pregnant mothers. Mothers (N = 70) provided a late pregnancy stool sample and filled in questionnaires on general and pregnancy-specific stress and anxiety. Bacterial DNA was extracted and analysed by Illumina HiSeq sequencing of PCR-amplified 16 S ribosomal RNA gene fragments. Associations between maternal general anxiety and microbial composition were found. No associations between the other measured psychosocial stress variables and the relative abundance of microbial groups were detected. This study shows associations between maternal pregnancy general anxiety and microbial composition, providing first evidence of a mechanism through which psychological symptoms in pregnancy may affect the offspring.

Childhood urbanicity and hair steroid hormone levels in ten-year-old children.

BACKGROUND: Research suggests that it may be more stressful for children to grow up in an urban area than in a rural area. Urbanicity may affect physiological stress system functioning as well as the timing of sexual maturation. The purpose of the current study was to investigate whether moderate urbanicity (current and childhood, ranging from rural areas to small cities) was associated with indices of long-term hypothalamic-pituitary-adrenal and hypothalamic-pituitary-gonadal axis functioning (cortisol, cortisone, dehydroepiandrosterone and progesterone levels) and whether sex moderated any associations. METHOD: Children (N = 92) were all 10 years old and from the Dutch general population. Hair samples were collected and single segments (the three cm most proximal to the scalp) were assayed for concentrations of steroid hormones (LCMS/MS method). Neighborhood-level urbanicity and socioeconomic status were measured from birth through age ten years. Analyses were controlled for neighborhood- and family socioeconomic status, body mass index and season of sampling. RESULTS: The results from multivariate analyses of variance showed no associations between current or childhood moderate urbanicity and hair steroid hormone concentrations. Interaction terms between moderate urbanicity and sex were not statistically significant. CONCLUSIONS: Associations between urbanicity and steroid hormone levels may only be detectable in highly urban areas and/or during later stages of adolescence. Alternatively, our findings may have been due to most children being from families with a higher socioeconomic status.

Cortisol reactions to a social evaluative paradigm in 5- and 6-year-old children.

The goal of the present study was to develop a stress paradigm to elicit cortisol secretory responses in a group of 5- and 6-year-old children as a whole. To this end, we tested a paradigm containing elements of social evaluative threat, unpredictability and uncontrollability, and with a duration of 20 min. The Children's Reactions to Evaluation Stress Test is composed of three short tasks that children have to perform in front of a judge. The tasks are rigged so as to provoke (partial) failure in the child's performance. Participants were 42 children (M = 68.0 months, SD = 4.3). Six saliva samples were taken during the testing session to obtain cortisol measurements of baseline concentrations, stress reactivity, and recovery. Our findings showed that this paradigm was effective in provoking a significant increase in salivary cortisol concentration in the group as a whole, with no effects of possible confounders (child's sex, age or school, parental educational level, time of testing, sex of experimenter, and sex of judge). The mean cortisol concentration increase for the group was 127.5% (SD = 190.9); 61% of the children could be classified as reactors (mean increase of 214%, SD = 201.5), and 39% as non-reactors (mean decrease of 7.8%, SD = 16.8). To our knowledge, this is the first study in this age group that shows a significant cortisol response for the group as a whole to a standardized laboratory paradigm. As such, this paradigm is a promising tool to be used in future research on early life interactions between physiology and psychology.

Solitary sleeping in young infants is associated with heightened cortisol reactivity to a bathing session but not to a vaccination.

BACKGROUND: In this prospective longitudinal study, we investigated the relation between sleeping arrangements and infant cortisol reactivity to stressors in the first two post-natal months. Co-sleeping, as compared to solitary sleeping, is hypothesized to provide more parental external stress regulation by night, thus reducing general stress sensitivity. We therefore expected lower cortisol reactivity to stress in infants who co-slept more regularly. METHODS: Participants were 163 mothers and infants from uncomplicated, singleton pregnancies. Mothers completed daily diaries on sleeping arrangements in the first 7 weeks of life. Co-sleeping was defined as sleeping in the parents' bedroom (i.e. own or parents' bed). Cortisol reactivity was measured twice: to a mild physical stressor (bathing session) at 5 weeks of age and to a mild pain stressor (vaccination) at 2 months of age. RESULTS: Infants with a solitary sleeping arrangement in their first month of life showed a heightened cortisol response to the bathing session at 5 weeks compared to infants that co-slept regularly. This effect was not explained by breastfeeding practices, maternal caregiving behavior, or infants' night waking and sleep duration. No effects were found of co-sleeping on the cortisol response to the vaccination at 2 months. CONCLUSIONS: The results suggest that solitary sleeping in the first month of life is associated with heightened sensitivity of the HPA-axis to a mild stressor, possibly due to less nocturnal parental availability as external stress regulator. Whether this effect continues in later life, remains to be investigated.

Maternal prenatal stress and cortisol reactivity to stressors in human infants.

Early life factors can shape the development of hypothalamic pituitary adrenal (HPA) axis. Maternal prenatal stress might constitute such an early environmental factor. As little is known about the relation between maternal prenatal stress and cortisol reactivity in human offspring, we performed a longitudinal study including four assessments of infant cortisol reactivity to stressful events in a non-clinical population. General and pregnancy-related feelings of stress and anxiety, as well as circadian cortisol levels, were measured in 173 mothers in the last trimester of pregnancy. Infant cortisol reactivity was measured at 5 weeks to a bathing session, at 8 weeks to a vaccination, at 5 months to a stressful mother-infant interaction (still face procedure), and at 12 months to a maternal separation (strange situation procedure). Maternal prenatal fear of bearing a handicapped child was a consistent predictor of infant cortisol reactivity. Although the effects were mild, higher fear was significantly related to higher salivary cortisol reactivity to the bathing session and to decreased cortisol reactivity to vaccination and maternal separation. Thus, pregnancy-specific anxieties predict infant cortisol reactivity in the first year of life, but the direction of the effect depends on infant age and/or the nature of the stressor. While this specific anxiety was a better predictor than stress experience or maternal cortisol concentrations, the underlying mechanisms of these associations remain unclear. Future studies should try to incorporate multiple measures of HPA-axis reactivity during development when studying the long-term consequences of maternal prenatal stress.

Long-chain polyunsaturated fatty acid content in Dutch preterm breast milk; differences in the concentrations of docosahexaenoic acid and arachidonic acid due to length of gestation.

Recognizing the important role of long-chain polyunsaturated fatty acids (LCP) particularly in preterm infant nutrition, we studied the fatty acid composition of breast milk from 65 mothers of very preterm ( < 31 weeks of gestation) and preterm ( > or = 31 and < 36 weeks of gestation) infants. Fatty acids were determined as fatty acid methyl esters by capillary gas chromatography. In accordance with other studies, the increase of capric acid, lauric acid and myristic acid during lactation is influenced by prematurity. Unsaturated fatty acids had the inclination to decrease. Our interest was mainly focused on docosahexaenoic acid (DHA) and arachidonic acid (AA). Accelerated brain growth during the last trimester of gestation requires an extra need for these LCPs. In our study, preterm milk after a gestation period of at least 32 weeks contained the highest amounts of DHA and AA. The Western maternal diet is considered to be low in omega 3 fatty acids, that is why the concentration of DHA in our preterm milk can be regarded as a low amount. As it is the milk of their mothers, and because the amounts are higher than normally found in Western full term breast milk, the contribution of DHA to preterm milk fat (0.34%) might be considered, for the time being, as a safe natural guideline for formulas for preterm infants.

Composition of premature breast-milk during lactation: constant digestible protein content (as in full term milk).

There is much discussion about the protein requirements of (very) preterm infants. The protein content of breast milk plays an important role in this discussion. For this reason, we took a close look at the protein content and its composition in premature breast milk. Complete 24 h expressions-were examined using the Kjedahl method, GPC, SDS-PAGGE and nephelometric detection of sIgA. Colostrum of premature breast milk contains a large amount of undigestible proteins, up to 70% of true protein, which decreases to 20-40% in transitory and mature preterm milk. The NPN fraction of mature preterm breast milk was, dependent on the degree of prematurity 20-25%; increasing during lactation from about 18% to 22-26%. This means that, depending on the lactation period only 30-60% of the total protein content of breast milk is available for body protein synthesis. In absolute amounts, digestible protein is reasonably stable during lactation.