Mother And late Preterm Lactation Study (MAPLeS): a randomised controlled trial testing the use of a breastfeeding meditation by mothers of late preterm infants on maternal psychological state, breast milk composition and volume, and infant behaviour and growth

Background

Late preterm infants suffer from more complications and are less likely to be breastfed compared to term infants and their mothers experience higher levels of stress than mothers with term infants. The physiological or hormonal responses that influence milk ejection, milk production, and/or maternal behaviour are possible mechanisms by which maternal distress could negatively influence breastfeeding success. Maternal mood might also affect infant behaviour (feeding, sleeping, and crying) through changes in milk volume and composition, and consequently breastfeeding success and infant growth. Previous research, using relaxation therapy in 64 Malaysian first-time mothers breastfeeding their full-term infants, demonstrated that the therapy was effective in reducing maternal stress and improving infant growth. We hypothesise that expected benefits are even greater in a more vulnerable population where additional breastfeeding support is especially needed, such as in mothers of late preterm infants.

Methods/design

This protocol describes our randomised controlled trial that tests whether a breastfeeding meditation audio reduces maternal stress in mothers of late preterm infants in London. Home visits will be conducted at 2–3 and 6–8 weeks post-delivery. Participants will be randomised to a control group or an intervention group, where mothers will be asked to listen to a meditation tape on a daily basis while breastfeeding. The main outcomes of the intervention will be maternal stress markers and infant weight Z-score. Potential mediators will be the secondary outcomes and include breast milk macronutrient and hormone levels (ghrelin, leptin, cortisol, and adiponectin), milk volume assessed by 48-h test-weighing, and maternal engagement with the infant. Infant behaviour, including crying and sleeping, and infant appetite will be evaluated. Data about other mediators such as maternal perception of milk supply and salivary oxytocin will be collected.

Discussion

We hypothesise that the use of the breastfeeding meditation will reduce maternal stress and consequently improve infant growth mediated by changes in milk composition and volume and maternal behaviour. This study will allow us to understand the mother–infant factors that influence breastfeeding in late preterm infants and potentially identify a method that could improve mother, infant, and breastfeeding outcomes.

Trial registration

ClinicalTrials.gov, NCT03791749. Registered 1 January 2019.

Bottlenose dolphin calves have multi-year elevations of plasma oxytocin compared to all other age classes

Providing for infants nutritionally via lactation is one of the hallmarks of mammalian reproduction, and infants without motivated mothers providing for them are unlikely to survive. Mothers must maintain regular contact with infants both spatially and temporally while utilising their environment to forage, avoid threats and find shelter. However, mothers can only do this and maximise their reproductive success with some degree of co-operation from infants, despite their developing physical and cognitive capabilities. The neuropeptide hormone oxytocin (OT) triggers proximity-seeking behaviour and acts in a positive feedback loop across mother-infant bonds, stimulating appropriate pro-social behaviour across the pair. However, data on infant OT levels is lacking, and it is unclear how important infants are in maintaining mother-infant associations. The bottlenose dolphin (Tursiops truncatus) is a mammalian species that is fully physically mobile at birth and has multi-year, but individually variable, lactation periods. We investigated OT concentrations in mother-infant pairs of wild individuals compared to other age and reproductive classes. An ELISA to detect OT in dolphin plasma was successfully validated with extracted plasma. We highlight a statistical method for testing for parallelism that could be applied to other ELISA validation studies. OT concentrations were consistently elevated in calves up to at least 4 years of age with lactating mothers (12.1 ± 0.9 pg/ml), while all mothers (4.5 ± 0.4 pg/ml) had OT concentrations comparable to non-lactating individuals (5.9 ± 0.5 pg/ml). Concentrations within infants were individually variable, and may reflect the strength of the bond with their mother. The OT system likely provides a physiological mechanism for motivating infants to perform behaviours that prevent long-term separation from their mothers during this crucial time in their life history. Elevated infant OT has also been linked to energetic and developmental advantages which may lead to greater survival rates. Environmental or anthropogenic disturbances to OT release can occur during bond formation or can disrupt the communication methods used to reinforce these bonds via OT elevation. Variation in OT expression in infants, and its behavioural and physiological consequences, may explain differences in reproductive success despite appropriate maternal behaviour expression.

Effects of relaxation therapy on maternal psychological state, infant growth and gut microbiome: protocol for a randomised controlled trial investigating mother-infant signalling during lactation following late preterm and early term delivery

Background

Breastfeeding is of great importance for infant health both short and long term, especially for those born preterm. Apart from the socio-economic and cultural factors which may influence a mother's decision on breastfeeding, lactation performance is also influenced by maternal physiological and psychological condition, as well as infant behavioural factors. The aim of this project is to investigate physiological, psychological and anthropological aspects of 'signalling' between mother and infant during lactation in a stressful situation, following late preterm delivery, using an experimental approach.

Method

A single blind parallel randomised controlled trial will be conducted in Chinese primiparous mothers who deliver a infant (34 0/7-37 6/7) weeks and plan to exclusively breastfeed. Mothers will be recruited from four local community clinics attached to Beijing Children Hospital. Two home visits will be arranged at one week and eight weeks postpartum. Participants will be randomly assigned to either intervention arm or control (no intervention) before the first home visit. Mothers from the intervention group will be asked to listen to an audio recording with relaxation meditation daily during breastfeeding. Maternal stress and anxiety will be measured at one week and eight week postpartum using Chinese version of Cohen's Perceived Stress Scale (PSS) and Beck Anxiety Inventory (BAI). Infant weight and length gain (as SD scores) from one to eight week will be measured using anthropometry. Milk volume will be measured using 48-h test-weighing method. Breast milk samples and mother and infant's stool samples will be collected to measure macronutrient and microbiome content. Anthropometric measurements (weight, length and head circumference) will be performed during all home visits.

Discussion

Primary outcomes of this study will be the effect of the intervention on maternal psychological state, and infant growth. Other outcomes will include the effect of the intervention on milk production, infant behaviours, and the microbiome composition in breastmilk and maternal and infant's gut. Results of this study will provide greater understanding about maternal-infant factors which influence the success of breastfeeding, and which may then be useful targets for future interventions.

Trial registration

ClinicalTrials.gov identifier: NCT03674632. Registered 14 September 2018.

Study protocol: An investigation of mother-infant signalling during breastfeeding using a randomised trial to test the effectiveness of breastfeeding relaxation therapy on maternal psychological state, breast milk production and infant behaviour and growth

Background

The physiological and psychological signalling between mother and infant during lactation is one of the prominent mother-infant factors that may influence breastfeeding outcomes. The infant can ‘signal’ his needs through vocalisation, and the mother can respond by allowing or restricting nipple access, which might alter the breast milk composition or volume. This may lead to parent-offspring conflict during the lactation period. Challenging infant behaviour has also been associated with maternal psychological distress, which might affect breastfeeding performance. Most attempts to improve breastfeeding rates focus on providing additional support, yet many aspects of the breastfeeding process are poorly understood. Thus, our objective is to investigate mother-infant signalling during breastfeeding by manipulating maternal psychological state using a relaxation therapy intervention. The study will test the hypothesis that mothers who listen to the therapy will be more relaxed/less stressed and this will favourably alter breast milk composition and/or affect milk volume and hence influence infant outcomes.

Methods

A randomised controlled trial will be conducted in first-time breastfeeding mothers and their new-born infants. Pregnant mothers will be recruited at antenatal clinics in Selangor, Malaysia, and four home visits will be carried out at 2, 6, 12 and 14 weeks postnatally. Participants will be randomised into a control and an intervention group in the early post-partum period. Mothers from the intervention group will be asked to listen daily to an audio recording with relaxation therapy during breastfeeding. Maternal psychological state, breastfeeding practices and infant behaviour will be assessed using validated questionnaires. Milk volume will be measured using stable isotopes. Breast milk samples will be collected to measure macronutrient content and hormone levels. Anthropometric measurements (weight, length and head circumference) will be performed during all home visits, including body composition at week 14.

Discussion

The main outcomes will be the effect of the intervention on maternal psychological state, milk production, cortisol levels, and infant behaviour and growth. Secondary outcomes will be associations between breast milk composition and infant appetite and growth. This study aims to provide a greater understanding of maternal-infant factors which influence breastfeeding outcomes and which may be useful targets for future interventions.

Trial registration

ClinicalTrials.gov identifier: NCT01971216.

Maternal prenatal cortisol predicts infant negative emotionality in a sex-dependent manner

OBJECTIVE

Prenatal stress influences fetal developmental trajectories, which may implicate glucocorticoid mechanisms. There is also emerging evidence that effects of prenatal stress on offspring development are sex-dependent. However, little is known about the prospective relationship between maternal prenatal cortisol levels and infant behaviour, and whether it may be different in male and female infants. We sought to address this question using data from a prospective longitudinal cohort, stratified by risk.

METHOD

The Wirral Child Health and Development Study (WCHADS) cohort (n=1233) included a stratified random sub-sample (n=216) who provided maternal saliva samples, assayed for cortisol, at home over two days at 32weeks of pregnancy (on waking, 30-min post-waking and during the evening) and a measure of infant negative emotionality from the Neonatal Behavioural Assessment Scale (NBAS) at five weeks-of-age. General population estimates of associations among measures were obtained using inverse probability weights.

RESULTS

Maternal prenatal cortisol sampled on waking predicted infant negative emotionality in a sex-dependent manner (interaction term, p=0.005); female infants exposed to high levels of prenatal cortisol were more negative (Beta=0.440, p=0.042), whereas male infants were less negative (Beta=-0.407, p=0.045). There was no effect of the 30-min post-waking measure or evening cortisol.

DISCUSSION

Our findings add to an emerging body of work that has highlighted sex differences in fetal programming, whereby females become more reactive following prenatal stress, and males less reactive. A more complete understanding of sex-specific developmental trajectories in the context of prenatal stress is essential for the development of targeted prevention strategies.