Oxytocin and early parent-infant interactions: A systematic review

Objectives

Social relationships throughout lifespan are critical for health and wellbeing. Oxytocin, often called the ‘hormone of attachment’ has been suggested as playing an important role in early-life nurturing and resulting social bonding. The objective of this paper is to synthesize the associations between oxytocin levels and interactions between infants and parents that may trigger oxytocin release, and in turn facilitate attachments.

Methods

A comprehensive cross-disciplinary systematic search was completed using electronic databases. The inclusion criteria included studies that focused on mother-infant and father-infant interaction and measured both baseline and post-interaction oxytocin levels.

Results

Seventeen studies were included in the final systematic review. The reviewed studies used mother-infant and/or father-infant play and skin-to-skin contact between maternal-infant and paternal-infant dyads to examine the oxytocin role in early life bonding and parenting processes. Studies showed a positive correlation between parent-infant contact and oxytocin levels in infancy period. Increased maternal oxytocin levels were significantly related to more affectionate contact behaviors in mothers following mother-infant contact, synchrony, and engagement. Meanwhile, increased paternal oxytocin levels were found to be related to more stimulatory contact behaviors in fathers following father-infant contact. Oxytocin levels significantly increased in infants, mothers and fathers during skin-to-skin contact and parents with higher oxytocin levels exhibited more synchrony and responsiveness in their infant interactions.

Conclusion

The review suggests that oxytocin plays an important role in the development of attachment between infants and parents through early contact and interaction. The complexities of oxytocinergic mechanisms are rooted in neurobiological, genetic, and social factors.

Synthesis of Mixed Research on Posttraumatic Stress Related to Traumatic Birth

OBJECTIVE

To synthesize mixed-research results (quantitative and qualitative) on posttraumatic stress in women who experienced traumatic births.

DATA SOURCES

PubMed, Scopus, and PsycINFO databases.

STUDY SELECTION

Quantitative and qualitative studies were included if they were published in English from January 1, 2009, through December 31, 2018, and focused on posttraumatic stress in the postpartum period related to traumatic childbirth.

DATA EXTRACTION

The final sample consisted of 59 studies: 4 qualitative and 55 quantitative. Both authors independently appraised each study using the Critical Appraisal Skills Programme. Quantitative studies were synthesized by narrative synthesis and vote counting, and qualitative studies were synthesized by content analysis.

DATA SYNTHESIS

In the included studies, prevalence rates of elevated posttraumatic stress ranged from 0.8% to 26%. Significant predictors of posttraumatic stress that occurred before childbirth and those that were birth related were identified. Reports of six intervention studies to decrease posttraumatic stress symptoms after traumatic births were included. These interventions focused on postnatal debriefing, expressive writing, online cognitive behavioral therapy, a brief cognitive intervention, and the implementation of the nine instinctive stages of the infant during the first hour after birth. We created four themes from the findings of the qualitative studies: Distressing Symptoms, Detrimental Effect of Posttraumatic Stress on Women's Relationships With Their Infants and Partners, Critical Influence ofSupport, and Debriefing.

CONCLUSION

When a woman experiences posttraumatic stress related to a traumatic birth, the entire family unit is vulnerable. Findings from quantitative predictor studies can be used to develop an instrument to screen women for risk factors for posttraumatic stress related to birth trauma. Primary interventions are needed to prevent women from experiencing traumatic births.

Very preterm birth is associated with PLAGL1 gene hypomethylation at birth and discharge

AIM

Recent findings show that DNA methylation is susceptible to very preterm (VPT) birth and to the experience of the early stay in the neonatal intensive care unit. The aim of the study was to compare PLAGL1 methylation between VPT and full-term (FT) infants at birth as well as between VPT infants at discharge and FT infants at birth.

METHODS

DNA was collected from cord blood of 56 VPT and 27 FT infants at birth and from peripheral blood in VPT infants at neonatal intensive care unit discharge. Sociodemographic and neonatal variables were considered.

RESULTS

PLAGL1 methylation at birth and at discharge were highly correlated in VPT infants. Lower methylation emerged in VPT infants at birth and discharge compared to FT counterparts.

CONCLUSION

PLAGL1 hypomethylation emerged as a potential epigenetic mark of VPT birth. Future research is warranted to assess the functional consequences of PLAGL1 diminished methylation in VPT infants' development.

Validation of Egg Yolk Antibody Testing as a Method to Determine Influenza Status in White Leghorn Hens

Determination of the avian influenza (AI) status of a flock has traditionally been done by detection of serum antibodies. However, for many diseases, detection of antibodies in egg yolk has been effective in monitoring the disease status of laying flocks. This study compared the utility of egg yolk vs. serum for determining AI status in laying hen flocks. Specific-pathogen-free white leghorn hens were inoculated via the respiratory tract with a low-pathogenic H7N2 AI virus or sterile allantoic fluid or subcutaneously with an inactivated oil emulsion vaccine produced from the same AI virus or normal allantoic fluid. Antibody levels were determined by the agar gel immunodiffusion (AGID) test, the hemagglutination-inhibition (HI) test, and the enzyme-linked immunosorbent assay (ELISA). Anti-influenza antibodies were detected in sera of all live virus-inoculated hens by day 7 postinoculation (PI) (AGID and ELISA tests), but detection of antibodies in egg yolk was delayed by a few days, with all being positive by day 14 PI. Sera from all vaccinated hens were positive by day 14 PI (AGID and ELISA tests), and egg yolk was positive by day 18 PI. The HI test was less sensitive than the ELISA and AGID tests in detecting anti-influenza antibodies in both sera and yolk. Serum and yolk from all control birds remained negative throughout the study. These studies show that currently used serologic tests can detect antibodies in serum and yolk samples from hens exposed to live AI virus or from those that have been vaccinated. Antibody is detected earlier in the serum than in the yolk and antibody is detected earlier from birds exposed to a live infection compared to birds vaccinated with an inactivated oil emulsion vaccine.