Who plays the strings in newborn analgesia at birth, vasopressin or oxytocin?

Palliative Care in the Delivery Room: Challenges and Recommendations

Palliative care in the delivery room is an interprofessional and interdisciplinary challenge addressing the dying newborn and parents as well as the caregivers. It differs in some significant aspects from palliative care in the neonatal intensive care unit. Clinical experience suggests that many details regarding this unique specialized palliative care environment are not well known, which may result in some degree of insecurity and emotional distress for health care providers. This article presents basic background information regarding the provision of palliative care to newborns within the delivery room. It offers orientation along with a preliminary set of practical recommendations regarding the following central issues: (i) the basic elements of perinatal palliative care, (ii) the range of non-pharmacological and pharmacological interventions available for infant symptom control near the end of life, (iii) meeting the personal psychological, emotional, and spiritual needs of the parents, and (iv) care and self-care for medical personnel.

Exocrine scent marking: Coordinative role of arginine vasopressin in the systemic regulation of social signaling behaviors

Arginine vasopressin (AVP) is a neurohypophysial hormone that coordinatively regulates central socio-emotional behavior and peripheral control of antidiuretic fluid homeostasis. Most mammals, including rodents, utilize exocrine or urine-contained scent marking as a social signaling tool that facilitates social adaptation. The exocrine scent marking behavior is postulated to fine-tune sensory and cognitive abilities to recognize key social features via exocrine/urinary olfactory cues and subsequently control exocrine deposition or urinary marking through the mediation of osmotic fluid balance. AVP is implicated as a major player in controlling both recognition and signaling responses. This review provides constructive hypotheses on the coordinative processes of the AVP neurohypophysial circuits in the systemic regulations of fluid control and social-communicative behavior, via the expression of exocrine scent marking, and further emphasizes a potential role of AVP in a common mechanism underlying social communication in rodents.

Vasopressin but Not Oxytocin Responds to Birth Stress in Infants

Context

Birth triggers a large fetal neuroendocrine response, which is more pronounced in infants born vaginally than in those born by elective cesarean section (ECS). The two related peptides arginine vasopressin (AVP) and oxytocin (OT) play an essential role in peripheral and central stress adaptation and have a shared receptor mediating their function. Elevated cord blood levels of AVP and its surrogate marker copeptin, the C-terminal part of AVP prohormone, have been found after vaginal delivery (VD) as compared to ECS, while release of OT in response to birth is controversial. Moreover, AVP, copeptin and OT have not yet been measured simultaneously at birth.

Objective

To test the hypothesis that AVP but not OT levels are increased in infants arterial umbilical cord blood in response to birth stress and to characterize AVP secretion in direct comparison with plasma copeptin.

Methods

In a prospective single-center cross-sectional study, we recruited healthy women with a singleton pregnancy and more than 36 completed weeks of gestation delivering via VD or ECS (cesarean without prior uterine contractions or rupture of membranes). Arterial umbilical cord blood samples were collected directly after birth, centrifuged immediately and plasma samples were frozen. Concentrations of AVP and OT were determined by radioimmunoassay and that of copeptin by ultrasensitive immunofluorescence assay.

Results

A total of 53 arterial umbilical cord blood samples were collected, n = 29 from VD and n = 24 from ECS. Ten venous blood samples from pregnant women without stress were collected as controls. AVP and copeptin concentrations were significantly higher in the VD group than in the ECS group (both p < 0.001), median (range) AVP 4.78 (2.38–8.66) vs. 2.38 (1.79–3.88) (pmol/L), copeptin 1692 (72.1–4094) vs. 5.78 (3.14–17.97), respectively, (pmol/L). In contrast, there was no difference in OT concentrations (pmol/L) between VD and ECS, 6.00 (2.71–7.69) vs. 6.14 (4.26–9.93), respectively. AVP and copeptin concentrations were closely related (Rs = 0.700, p < 0.001) while OT did not show any correlation to either AVP or copeptin. In linear regression models, vaginal delivery and biochemical stress indicators, base deficit and pH, were independent predictors for both AVP and copeptin. OT was not linked to base deficit or pH.

Conclusion

Vaginal birth causes a profound secretion of AVP and copeptin in infants. Whereas AVP indicates acute stress events, copeptin provides information on cumulative stress events over a longer period. In contrast, fetal OT is unaffected by birth stress. Thus, AVP signaling but not OT mediates birth stress response in infants. This unique hormonal activation in early life may impact neurobehavioral development in whole life.

Birth elicits a conserved neuroendocrine response with implications for perinatal osmoregulation and neuronal cell death

Long-standing clinical findings report a dramatic surge of vasopressin in umbilical cord blood of the human neonate, but the neural underpinnings and function(s) of this phenomenon remain obscure. We studied neural activation in perinatal mice and rats, and found that birth triggers activation of the suprachiasmatic, supraoptic, and paraventricular nuclei of the hypothalamus. This was seen whether mice were born vaginally or via Cesarean section (C-section), and when birth timing was experimentally manipulated. Neuronal phenotyping showed that the activated neurons were predominantly vasopressinergic, and vasopressin mRNA increased fivefold in the hypothalamus during the 2–3 days before birth. Copeptin, a surrogate marker of vasopressin, was elevated 30-to 50-fold in plasma of perinatal mice, with higher levels after a vaginal than a C-section birth. We also found an acute decrease in plasma osmolality after a vaginal, but not C-section birth, suggesting that the difference in vasopressin release between birth modes is functionally meaningful. When vasopressin was administered centrally to newborns, we found an ~ 50% reduction in neuronal cell death in specific brain areas. Collectively, our results identify a conserved neuroendocrine response to birth that is sensitive to birth mode, and influences peripheral physiology and neurodevelopment.

Birth signalling hormones and the developmental consequences of caesarean delivery

Rates of delivery by caesarean section (CS) are increasing around the globe and, although several epidemiological associations have already been observed between CS and health outcomes in later life, more are sure to be discovered as this practice continues to gain popularity. The components of vaginal delivery that protect offspring from the negative consequences of CS delivery in later life are currently unknown, although much attention to date has focused on differences in microbial colonisation. Here, we present the case that differing hormonal experiences at birth may also contribute to the neurodevelopmental consequences of CS delivery. Levels of each of the 'birth signalling hormones' (oxytocin, arginine vasopressin, epinephrine, norepinephrine and the glucocorticoids) are lower following CS compared to vaginal delivery, and there is substantial evidence for each that manipulations in early life results in long-term neurodevelopmental consequences. We draw from the research traditions of neuroendocrinology and developmental psychobiology to suggest that the perinatal period is a sensitive period, during which hormones achieve organisational effects. Furthermore, there is much to be learned from research on developmental programming by early-life stress that may inform research on CS, as a result of shared neuroendocrine mechanisms at work. We compare and contrast the effects of early-life stress with those of CS delivery and propose new avenues of research based on the links between the two bodies of literature. The research conducted to date suggests that the differences in hormone signalling seen in CS neonates may produce long-term neurodevelopmental consequences.

AVPR1A distribution in the whole C57BL/6J mouse neonate

The neuropeptide arginine vasopressin (AVP) plays significant roles in maintaining homeostasis and regulating social behavior. In vaginally delivered neonates, a surge of AVP is released into the bloodstream at levels exceeding release during life-threatening conditions such as hemorrhagic shock. It is currently unknown where the potential sites of action are in the neonate for these robust levels of circulating AVP at birth. The purpose of this study is to identify the location of AVP receptor 1a (AVPR1A) sites as potential peripheral targets of AVP in the neonatal mouse. RT-qPCR analysis of a sampling of tissues from the head demonstrated the presence of Avpr1a mRNA, suggesting local peripheral translation. Using competitive autoradiography in wildtype (WT) and AVPR1A knockout (KO) postnatal day 0 (P0) male and female mice on a C57BL/6J background, specific AVPR1A ligand binding was observed in the neonatal mouse periphery in sensory tissues of the head (eyes, ears, various oronasal regions), bone, spinal cord, adrenal cortex, and the uro-anogenital region in the neonatal AVPR1A WT mouse, as it was significantly reduced or absent in the control samples (AVPR1A KO and competition). AVPR1A throughout the neonatal periphery suggest roles for AVP in modulating peripheral physiology and development of the neonate.

Birth experience in newborn infants is associated with changes in nociceptive sensitivity

Vaginal birth prepares the fetus for postnatal life. It confers respiratory, cardiovascular and homeostatic advantages to the newborn infant compared with elective cesarean section, and is reported to provide neonatal analgesia. We hypothesize that infants born by vaginal delivery will show lower noxious-evoked brain activity a few hours after birth compared to those born by elective cesarean section. In the first few hours of neonatal life, we record electrophysiological measures of noxious-evoked brain activity following the application of a mildly noxious experimental stimulus in 41 infants born by either vaginal delivery or by elective cesarean section. We demonstrate that noxious-evoked brain activity is related to the mode of delivery and significantly lower in infants born by vaginal delivery compared with those born by elective cesarean section. Furthermore, we found that the magnitude of noxious-evoked brain activity is inversely correlated with fetal copeptin production, a surrogate marker of vasopressin, and dependent on the experience of birth-related distress. This suggests that nociceptive sensitivity in the first few hours of postnatal life is influenced by birth experience and endogenous hormonal production.

Birth delivery mode alters perinatal cell death in the mouse brain

Labor and a vaginal delivery trigger changes in peripheral organs that prepare the mammalian fetus to survive ex utero. Surprisingly little attention has been given to whether birth also influences the brain, and to how alterations in birth mode affect neonatal brain development. These are important questions, given the high rates of cesarean section (C-section) delivery worldwide, many of which are elective. We examined the effect of birth mode on neuronal cell death, a widespread developmental process that occurs primarily during the first postnatal week in mice. Timed-pregnant dams were randomly assigned to C-section deliveries that were yoked to vaginal births to carefully match gestation length and circadian time of parturition. Compared with rates of cell death just before birth, vaginally-born offspring had an abrupt, transient decrease in cell death in many brain regions, suggesting that a vaginal delivery is neuroprotective. In contrast, cell death was either unchanged or increased in C-section-born mice. Effects of delivery mode on cell death were greatest for the paraventricular nucleus of the hypothalamus (PVN), which is central to the stress response and brain-immune interactions. The greater cell death in the PVN of C-section-delivered newborns was associated with a reduction in the number of PVN neurons expressing vasopressin at weaning. C-section-delivered mice also showed altered vocalizations in a maternal separation test and greater body mass at weaning. Our results suggest that vaginal birth acutely impacts brain development, and that alterations in birth mode may have lasting consequences.

Delivery room deaths of extremely preterm babies: an observational study

OBJECTIVE

Many extremely preterm neonates die in the delivery room (DR) after decisions to withhold or withdraw life-sustaining treatments or after failed resuscitation. Specific palliative care is then recommended but sparse data exist about the actual management of these dying babies. The objective of this study was to describe the clinical course and management of neonates born between 22 and 26 weeks of gestation who died in the DR in France.

DESIGN, SETTING, PATIENTS

Prospective study including neonates, who were liveborn between 22⁺⁰ and 26⁺⁶ weeks of gestation and died in the DR in 2011, among infants included in the EPIPAGE-2 study at the 18 centres participating in this substudy of extremely preterm neonates. Data were collected by a questionnaire completed by the professional caring for each baby.

RESULTS

The study included 73 children, with a median (IQR) gestational age of 24 (23-24) weeks. Median (IQR) duration of life was 53 (20-82) min. All but one were both wrapped and warmed. Pain was assessed for 72%, although without using any scale. Gasping was described for 66%. Comfort medications were administered to 35 children (50%), significantly more frequently to babies with gasping (p=0.001). Mother-child contact was reported for 78%, and psychological support offered to parents of 92%.

CONCLUSIONS

Non-pharmacological comfort care and parental support were routinely given. Comfort medication was given much more frequently than previously reported in other DRs. These data should encourage work on the indications for comfort medication and the interpretation of gasping.

Arginine Vasopressin and Copeptin in Perinatology

Arginine vasopressin (AVP) plays a major role in the homeostasis of fluid balance, vascular tonus, and the regulation of the endocrine stress response. The measurement of AVP levels is difficult due to its short half-life and laborious method of detection. Copeptin is a more stable peptide derived from the same precursor molecule, is released in an equimolar ratio to AVP, and has a very similar response to osmotic, hemodynamic, and stress-related stimuli. In fact, copeptin has been propagated as surrogate marker to indirectly determine circulating AVP concentrations in various conditions. Here, we present an overview of the current knowledge on AVP and copeptin in perinatology with a particular focus on the baby's transition from placenta to lung breathing. We performed a systematic review of the literature on fetal stress hormone levels, including norepinephrine, cortisol, AVP, and copeptin, in regard to birth stress. Finally, diagnostic and therapeutic options for copeptin measurement and AVP functions are discussed.

Primary palliative care in the delivery room: patients' and medical personnel's perspectives

OBJECTIVE

To investigate circumstances of primary palliative care (PPC) in the delivery room (DR), medical personnel's experience with neonates who died under PPC in the DR and perceived sources of care-related distress in DR staff.

STUDY DESIGN

Retrospective chart review of all neonates who were cared for under PPC in the DR during the years 2000-2010 at Charité University Medical Center Berlin, and structured face-to-face interviews with DR nursing staff and physicians.

RESULT

Neonates undergoing PPC could be grouped as preterm infants at the limits of viability with a gestational age between 22 (0)/7 and 23 (6)/7 weeks (n=86, 76%) and newborn infants with complex chronic conditions (n=27, 24%). The median age of neonates at death was 59 min (interquartile range [IQR] 28-105 min). Most of DR staff did not report relevant signs of distress in dying neonates, and providing palliative care was not named as a relevant care-related source of distress by medical personnel. However, half of the participants reported on high degrees of caregiver's emotional distress in PPC situations, identifying insecurity of how to communicate with parents and to provide emotional support as the most common source of distress.

CONCLUSION

Caregiver's emotional distress primarily originates from providing support to parents and not from providing medical care to the dying newborn. Implications for future practice include the need for structured education to improve DR staff's communication and counselling skills related to parents in PPC situations.

Oral glucose in preterm neonates during oropharyngeal suctioning: a randomized controlled cross-over trial

To investigate whether orally applied glucose reduces pain response during oropharyngeal suctioning in preterm infants with a birth weight >1500 g, we conducted a randomized, double-blind, placebo-controlled cross-over trial on 32 preterm infants undergoing oropharyngeal suctioning while on nasal continuous positive airway pressure (CPAP). The Premature Infant Pain Profile (PIPP) score was assessed and compared in a cross-over design to investigate whether there was a significant difference in the patients' pain response. The mean PIPP score during oropharyngeal suctioning after placebo was 8.6 (KI 7.8-9.4). After glucose administration, the mean PIPP score was 8.0 (KI 7.1-8.9). Comparison of the treatment effects reached no statistic significance (p = 0.23). During the oral study drug administration during nasal CPAP, we observed 47 adverse events, but none necessitated therapeutic intervention and none was classified as serious.

CONCLUSION

In our study, late preterm infants in the first days of life did not benefit significantly from analgesia with glucose during oropharyngeal suctioning. The oral administration of glucose under nasal CPAP led to no serious adverse events.

Neuroendocrinology of childbirth and mother-child attachment: the basis of an etiopathogenic model of perinatal neurobiological disorders

This review focuses on the neuroendocrine mechanisms in the mother and the newborn that are involved in the generation and consolidation of mother-child attachment. The role that different hormones and neurotransmitters play on the regulation of these mechanisms during parturition, the immediate postpartum period and lactation is discussed. Interferences in the initiation of mother-child attachment may have potential long-term effects for the behavior and affection of the newborn. Therefore, the possible consequences of alterations in the physiological neuroendocrine mechanisms of attachment, caused by elective Cesarean section, intrapartum hormonal manipulations, preterm delivery, mother-infant postpartum separation and bottle-feeding instead of breastfeeding are also discussed.

Is oxytocin a maternal-foetal signalling molecule at birth? Implications for development

The neuropeptide oxytocin was first noted for its capacity to promote uterine contractions and facilitate delivery in mammals. The study of oxytocin has grown to include awareness that this peptide is a neuromodulator with broad effects throughout the body. Accumulating evidence suggests that oxytocin is a powerful signal to the foetus, helping to prepare the offspring for the extrauterine environment. Concurrently, the use of exogenous oxytocin or other drugs to manipulate labour has become common practice. The use of oxytocin to expedite labour and minimise blood loss improves both infant and maternal survival under some conditions. However, further investigations are needed to assess the developmental consequences of changes in oxytocin, such as those associated with pre-eclampsia or obstetric manipulations associated with birth. This review focuses on the role of endogenous and exogenous oxytocin as a neurochemical signal to the foetal nervous system. We also examine the possible developmental consequences, including those associated with autism spectrum disorder, that arise from exogenous oxytocin supplementation during labour.