Effect of disturbance on labor. An experiment with 100 mice with dated pregnancies

Influence of the Physical Environment on Maternal Care for Culturally Diverse Women: A Narrative Review

OBJECTIVES

This narrative literature review aims to develop a framework that can be used to understand, study, and design maternal care environments that support the needs of women from diverse racial and ethnic groups.

BACKGROUND

Childbirth and the beginning of life hold particular significance across many cultures. People's cultural orientation and experiences influence their preferences within healthcare settings. Research suggests that culturally sensitive care can help improve the experiences and outcomes and reduce maternal health disparities for women from diverse cultures. At the same time, the physical environment of the birth setting influences the birthing experience and maternal outcomes such as the progression of labor, the use of interventions, and the type of birth.

METHODS

The review synthesizes articles from three categories: (a) physical environment of birthing facilities, (b) physical environment and culturally sensitive care, and (c) physical environment and culturally sensitive birthing facilities.

RESULTS

Fifty-five articles were identified as relevant to this review. The critical environmental design features identified in these articles were categorized into different spatial scales: community, facility, and room levels.

CONCLUSIONS

Most studies focus on maternal or culturally sensitive care settings outside the United States. Since the maternal care environment is an important aspect of their culturally sensitive care experience, further studies exploring the needs and perspectives of racially and ethnically diverse women within maternal care settings in the United States are necessary. Such research can help future healthcare designers contribute toward addressing the ongoing maternal health crisis within the country.

Not Just Mechanical Birthing Bodies: Birthing Consciousness and Birth Reflexes

There are two concepts of neuroendocrine reflexes associated with the expulsion of the fetus through the birth canal during the second stage of birth: the Ferguson reflex and the fetus ejection reflex. These concepts are often confused with one another and treated synonymously, thus interchangeable. However, the two not only refer to different phenomena, but they also represent the birthing woman differently. The Ferguson reflex treats the birthing woman as simply a biomechanical body. In contrast, the fetus ejection reflex does not ignore women's conscious states during birth and recognizes what is currently a well-known empirical fact: The event of birth is a complex biophysical process affected by many mental, social, and environmental factors. In that, it has a connection to the phenomenon of birthing consciousness, which is the positive altered state sometimes experienced during a physiological and undisturbed childbirth. We argue that birthing consciousness and the fetus ejection reflex, made possible by reduced cortical control, are extremely helpful in promoting physiological human childbirth. Therefore, treating a woman giving birth as a biomechanical body is not only erroneous but can also lead to medical mismanagement of the second stage of physiological childbirth with associated mental and physiological consequences.

Navigating intensive altered states of consciousness: How can the set and setting key parameters promote the science of human birth?

The subjective childbirth experience is crucial from a public health standpoint. There is a correlation between a negative childbirth experience and a poor mental state after birth, with effects that go far beyond the postpartum (PP) period. This paper offers a new approach as to how birthing experiences, and birth in general, can be navigated. The theory of set and setting proves that psychedelic experiences are shaped, first and foremost, by the mindset of an individual entering a psychedelic experience (set) and by the surroundings in which the experience happens (setting). In research on altered states of consciousness during psychedelic experiences, this theory explains how the same substance can lead to a positive and life-changing experience or to a traumatic and frightening experience. Because recent studies suggest that birthing women enter an altered state of consciousness during physiological birth ("birthing consciousness"), I suggest analyzing the typical modern birthing experience in terms of set and setting theory. I argue that the set and setting key parameters can help design, navigate, and explain many psychological and physiological elements of the human birth process. Thus, an operative conclusion that emerges from the theoretical analysis presented in this paper is that framing and characterizing the birth environment and birth preparations in terms of set and setting is a central tool that could be used to promote physiological births as well as subjective positive birthing experiences, which is currently a primary, yet unreached goal, in modern obstetrics and public health.

Birthing Consciousness as a Case of Adaptive Altered State of Consciousness Associated With Transient Hypofrontality

In this article, I present the concept of “birthing consciousness,” a psychophysical altered state of women that can occur during natural and undisturbed birth. I demonstrate that this altered state of consciousness (ASC) has phenomenological and cognitive features of hypofrontality; thus, birthing consciousness probably shares a similar brain mechanism to that postulated by the transient-hypofrontality theory (THT). I argue that until recently (with the advent of modern medical intervention), in evolutionary terms, women lacking the proclivity for this specific brain mechanism had a lower chance of reproducing successfully. Hence, I suggest a general and preliminary hypothesis concerning THT: Birthing consciousness is one example of an adaptive pain-induced ASC associated with transient hypofrontality.

Stress effects on the regulation of parturition in different domestic animal species

This review summarizes current knowledge on stress-like responses in parturient animals and their role for the onset and fine-tuning of parturition. The antepartum maternal cortisol increase is part of the endocrine changes that initiate parturition but a further increase in cortisol release during labor indicates a stress response. During the last minutes of delivery, sinus arrhythmias occur in 80% of foaling mares and 60% of calving cows. Expulsion of the neonate is thus characterized by parasympathetic dominance. In late-pregnant cows transported by road, cortisol concentrations increased but relations between transport stress and abortion remain unclear. In mares, transport not only elicited a stress response but also advanced the time of foaling. Transferring parturient rats, mice and pigs after birth of the first pup or piglet, respectively, to a stressful environment prolonged the time until delivery of the next littermate. In rats and pigs, this was caused by an increased opioidergic tone that restrained oxytocin release. In mice, a stress-induced delay of subsequent deliveries was caused by increased sympathoadrenal activity. When foaling mares were transferred to an uncomfortable stable at fetal membrane rupture, time until complete birth of the foal was doubled. As in mice, increased sympathetic activity was the mechanism delaying the progress of foaling. An increased sympathetic activity is also present in parturient cows disturbed during an early stage of calving. In equine and bovine neonates, the immediate postnatal period is characterised by high sympathetic activity and an increase in cortisol concentration, indicating a pronounced stress-like response.

External stress increases sympathoadrenal activity and prolongs the expulsive phase of foaling in pony mares

Mares usually give birth when they perceive their environment as safe and therefore disturbance at foaling may inhibit labor. In this study, foaling mares were transferred to an unfamiliar environment at rupture of the allantochorion (stress, n = 6) or were left undisturbed (control, n = 5). The progress of foaling, heart rate, heart rate variability (HRV) and plasma catecholamine, oxytocin and cortisol concentration were determined. In stressed mares, time from rupture of the allantochorion to appearance of the fetal feet (5.3 ± 1.1 vs. 1.6 ± 0.4 min) and total length of fetal expulsion were longer than in controls (both p < 0.05). Heart rate decreased during the expulsive phase of foaling in control mares (p < 0.01) but increased transiently in stressed mares. Heart rate calculated as percentage of the baseline was higher in stressed than in control mares (p = 0.05). HRV variables SDRR (standard deviation of the beat-to-beat interval) and RMSSD (root mean square of successive beat-to-beat differences) increased during foal expulsion (SDRR p < 0.01 and RMSSD p < 0.05). The increase in HRV was delayed in stressed compared to control mares (SDRR and RMSSD time x group p < 0.05). Plasma epinephrine and norepinephrine concentrations calculated as area under the curve for the expulsive phase of foaling were higher in stressed than control mares (p < 0.05). Concentrations of oxytocin and cortisol were elevated during foal expulsion (both p < 0.001) but not different between groups. In conclusion, disturbance of mares during expulsion of the foal prolonged foaling. This effect is most likely mediated via increased sympathetic activity and not inhibition of oxytocin release.

The Effect of Psychological Environment on Childbirth: Combined Cross -Cultural and Experimental Approach

A cross-cultural survey of birth patterning revealed marked differences in the speed of labor and indicated extreme variations in the psychological environment during labor and delivery. Speedier, easier labors appear to be related to acceptance of birth as a normal physiologic phenomena uncomplicated by sexual shame or fear-inducing rituals. The hypotheses developed from cross-cultural surveys were then tested experimentally in mice. Disturbance applied during labor resulted in reduction of labor speed immediately after the disturbance. Mice continuously disturbed at term delivered first pups significantly later, and had a 54% higher pup mortality rate. When expectant mice were rotated between familiar environment with shelter and glass fish bowl imbued with cat odor, spending equal amounts of time at each, significantly fewer births took place in the latter.

The effects of hydrotherapy on anxiety, pain, neuroendocrine responses, and contraction dynamics during labor

BACKGROUND

Hydrotherapy (immersion or bathing) is used worldwide to promote relaxation and decrease parturient anxiety and pain in labor, but the psychophysiological effects of this intervention remain obscure.

DESIGN

A pretest-posttest design with repeated measures was used to examine the effects of hydrotherapy on maternal anxiety and pain, neuroendocrine responses, plasma volume shift (PVS), and uterine contractions (CXs) during labor. Correlations among variables were examined at three time points (preimmersion and twice during hydrotherapy).

METHODS

Eleven term women (mean age 24.5 years) in spontaneous labor were immersed to the xiphoid in 37 degrees C water for 1 hr. Blood samples and measures of anxiety and pain were obtained under dry baseline conditions and repeated at 15 and 45 min of hydrotherapy. Uterine contractions were monitored telemetrically.

RESULTS

Hydrotherapy was associated with decreases in anxiety, vasopressin (V), and oxytocin (O) levels at 15 and 45 min (all ps < .05). There were no significant differences between preimmersion and immersion pain or cortisol (C) levels. Pain decreased more for women with high baseline pain than for women with low baseline levels at 15 and 45 min. Cortisol levels decreased twice as much at 15 min of hydrotherapy for women with high baseline pain as for those with low baseline pain. beta-endorphin (betaE) levels increased at 15 min but did not differ between baseline and 45 min. During immersion, CX frequency decreased. A positive PVS at 15 min was correlated with contraction duration.

CONCLUSIONS

Hydrotherapy during labor affects neuroendocrine responses that modify psychophysiological processes.

Exploring the effect of hospital admission on contraction patterns and labour outcomes using women's perceptions of events

OBJECTIVE

this study investigated the phenomenon of spontaneous labour contractions becoming less frequent on admission to hospital, which is observed anecdotally but is not evident in the literature. Anxiety in response to hospitalisation has been proposed to be responsible by initiating the biochemical response termed 'fight or flight'.

DESIGN

A non-experimental prospective design and a combination of quantitative and qualitative analysis. Data were collected using self-report labour diaries, postnatal questionnaires and hospital records of labour. Univariate analysis using t-test and chi(2)-test was performed to examine relationships between variables, and content analysis was undertaken on qualitative data regarding reactions to hospitalisation.

SETTING

hospital and community maternity services provided by a National Health Service hospital in Southern England in 1997.

PARTICIPANTS

about 87 women at least 37-week gestation, uncomplicated singleton pregnancy anticipating spontaneous labour with a live fetus.

MEASUREMENTS AND FINDINGS

labour diaries were analysed from 26 births. In three home births and 11 hospital births, labour contractions became more frequent, but in the remaining 12 labours, contractions decreased after admission to hospital. Women whose contractions slowed were not more anxious, but they rarely had cervical dilatation over 5cm and usually assumed a recumbent position in hospital. Artificial rupture of membranes was performed more frequently in these women, they used more pain relief and had a higher incidence of complicated childbirth; however, these differences were not statistically significant.

KEY CONCLUSIONS

labour contractions can increase or decrease in frequency following admission to hospital, and the change of frequency may be associated with stage of cervical dilatation and posture rather than anxiety.

IMPLICATIONS FOR PRACTICE

routine intervention to speed up labour on the basis of admission observations is called into question, and women should be made aware that slowing of contractions can occur as a normal part of changing the labour environment. Further research is needed to determine the physiological parameters of spontaneous labour and the role of posture in labour progress is needed.

Prenatal stress and risk for autism

This paper reviews several converging lines of research that suggest that prenatal exposure to environmental stress may increase risk for Autistic Disorder (AD). We first discuss studies finding that prenatal exposure to stressful life events is associated with significantly increased risk of AD, as well as other disorders, such as schizophrenia and depression. We then review evidence from animal and human studies that prenatal stress can produce both (a) abnormal postnatal behaviors that resemble the defining symptoms of AD, and (b) other abnormalities that have elevated rates in AD, such as learning deficits, seizure disorders, perinatal complications, immunologic and neuroinflammatory anomalies, and low postnatal tolerance for stress. We explain why an etiologic role for prenatal stress is compatible with genetic factors in AD, and describe how stress can disrupt fetal brain development. Finally, we discuss implications for understanding underlying processes in AD, including potential gene-environment interactions, and developing new therapies and early prevention programs.

Stress, ethanol, and neuroactive steroids

Neurosteroids play a crucial role in stress, alcohol dependence and withdrawal, and other physiological and pharmacological actions by potentiating or inhibiting neurotransmitter action. This review article focuses on data showing that the interaction among stress, ethanol, and neuroactive steroids may result in plastic molecular and functional changes of GABAergic inhibitory neurotransmission. The molecular mechanisms by which stress-ethanol-neuroactive steroids interactions can produce plastic changes in GABA(A) receptors have been studied using different experimental models in vivo and in vitro in order to provide useful evidence and new insights into the mechanisms through which acute and chronic ethanol and stress exposure modulate the activity of GABAergic synapses. We show detailed data on a) the effect of acute and chronic stress on peripheral and brain neurosteroid levels and GABA(A) receptor gene expression and function; b) ethanol-stimulated brain steroidogenesis; c) plasticity of GABA(A) receptor after acute and chronic ethanol exposure. The implications of these new mechanistic insights to our understanding of the effects of ethanol during stress are also discussed. The understanding of these neurochemical and molecular mechanisms may shed new light on the physiopathology of diseases, such as anxiety, in which GABAergic transmission plays a pivotal role. These data may also lead to the need for new anxiolytic, hypnotic and anticonvulsant selective drugs devoid of side effects.

Endogenous opioid regulation of oxytocin and ACTH secretion during pregnancy and parturition

Progress of parturition in the rat is optimal when there is increased oxytocin secretion, thus ensuring quick birth and otherwise risking adverse neonatal health. To ensure that the mechanisms for this are available, oxytocin neurons adapt in pregnancy and this includes development of a tonic inhibition by endogenous opioids. Endogenous opioid inhibition of oxytocin secretion increases in pregnancy, initially acting on the nerve terminals in the posterior pituitary and later on oxytocin cell bodies and their inputs. This inhibition enhances stores of oxytocin and enables restraint of oxytocin neuron responsiveness to selected excitatory inputs. The hypothalamic neurons which mediate stress also adapt in late pregnancy so that hypothalamo-pituitary-adrenal axis and oxytocin secretory responses to stressor exposure are attenuated. This is also partly due to endogenous opioid inhibition. Thus, in pregnancy oxytocin and hypothalamo-pituitary-adrenal axis secretion in response to stimulation is restrained, protecting the unborn fetus(es) from premature delivery and glucocorticoid exposure and preparing the oxytocin neurons for their important secretory role during parturition. In parturition itself, endogenous opioids continue to inhibit these neurons. Stress exposure during parturition delays births, probably due to endogenous opioid inhibition of pulsatile oxytocin secretion. On the other hand, basal ACTH and corticosterone secretion are reduced in parturition through inhibition by endogenous opioids. So, opioids continue to regulate the activity of oxytocin and hypothalamo-pituitary-adrenal mechanisms in labor; inhibition of oxytocin neurons at this time may control the spacing of pup births.

The theater of birth: scenes from women's scripts

An analogy between theater and birth is drawn from analyses of women's birth stories to describe birth from a fresh perspective. Birth and theater are compared using the theatrical production elements: setting, casting, props, set, behind the scenes, script, and roles. Selected examples from women's birth stories highlight each element. Nurses' roles are significant during labor and birth, but nurses' abilities to fulfill these roles are threatened. This analogy promotes rethinking of nursing actions in the theater of birth. Implications for clinical practice are provided, including altering the birth environment, offering choices, and maintaining the woman's role as star.

Hydrotherapy in labor

Maternal anxiety and pain prolong labor and contribute to fetal distress. Hydrotherapy during labor may promote relaxation and decrease pain without the risks caused by other treatments. In this pilot study the psychophysiological effects of hydrotherapy on maternal anxiety and pain during labor were examined. Using a randomized, pretest-posttest control group design with repeated measures, 18 term parturients were assigned to a control or an experimental group. Experimental subjects were placed in a tub of 37 degrees C water for 1 hr during early labor. The Wilcoxon two-sample test revealed statistically significant effects. At 15 min bathers' anxiety and pain scores were decreased compared to nonbathers. At 60 min bathers' pain scores were decreased compared to nonbathers. After 15 min of immersion, bathers had a significantly greater increase in plasma volume than nonbathers. No significant differences were found in urine catecholamines or maternal-fetal complications. The small sample limits conclusions, but the findings offer preliminary support for the therapeutic effects of bathing in labor for acute, short-term anxiety and pain reduction.

Accumulation of cyclooxygenase-2 gene transcripts in uterine tissues of pregnant and parturient cows: stimulation by oxytocin

Cyclooxygenase 1 and 2 (COX-1 and COX-2) mRNA were measured by ribonuclease protection assays in total RNA extracted from intercaruncular and caruncular endometrium, myometrium, cotyledons, and cervical mucosa of pregnant cows. Tissues were obtained at gestational ages of 150 days and 275 days and at term not in labor, at term in labor, and 6-12 h postpartum. Additionally, the effect of oxytocin (OT) on COX-2 expression was determined in intercaruncular endometrium of six third-trimester cows (between 230 and 270 days of pregnancy), three of which were injected with OT (200 IU) and three with saline 2 h before tissues were harvested. Prostaglandin F2alpha (PGF2alpha) metabolite was measured in plasma samples taken at 15-min intervals before and after the injections. Results showed that COX-2 mRNA was expressed in every type of tissue examined, although in different concentrations and beginning at different stages. Other than in seminal vesicular and prostate glands used as positive controls, low concentrations of COX-1 mRNA were detected only in myometrium and caruncles. Cotyledons had the highest concentration of COX-2 transcripts at all stages studied. Caruncles had about half the concentration of COX-2 transcripts that was seen in cotyledons, and on Day 150 even less. COX-2 mRNA expression in both tissues increased with advancing gestation, but there was no difference between samples from term-no-labor and term-in-labor cows. COX-2 mRNA concentrations in endometrium and myometrium were low; they varied randomly during pregnancy with no significant increase until postpartum, when COX-2 transcripts in endometrium had increased severalfold whereas those in myometrium were similar to values before parturition. Cervical mucosa expressed COX-2 mRNA weakly until term but had increased markedly at parturition. Injection of 200 IU of OT induced a substantial increase in endometrial COX-2 mRNA concentration within 2 h; this was associated with linearly increasing plasma concentrations of 13, 14-hydroxy-15-keto-prostaglandin F2alpha, which were still rising at termination of the experiment. The results suggest that endogenous OT is a major factor in induction of COX-2 expression and PGF2alpha release at term and during parturition in cows.

Naloxone prevents interruption of parturition and increases plasma oxytocin following environmental disturbance in parturient sows

Experiments in rodents have suggested that environmental disturbance can disrupt parturition through an opioid-mediated inhibition of oxytocin secretion. To test this hypothesis in a large animal model, 14 primiparous female pigs were allowed to commence parturition in a strawed pen. Five of these gilts were allowed to continue parturition undisturbed in this pen, while the remainder were moved to a farrowing crate immediately after the birth of the first piglet. At this time, pigs were injected subcutaneously with either the opioid antagonist naloxone (n = 4; dose 1 mg/kg body weight) or saline (n = 5). Whereas the undisturbed pigs all gave birth to a second piglet within 53 min, in three of the five disturbed and saline-treated pigs no further births occurred for 2 h, at which time oxytocin was administered subcutaneously to restart parturition. By contrast, all of the naloxone-treated pigs gave birth spontaneously within 2 h, although mean interbirth intervals were still prolonged compared to undisturbed pigs. In a second experiment, nine primiparous female pigs with chronic catheters preplaced in the external jugular vein were similarly moved after the birth of their first piglet and either injected with naloxone (n = 5) or saline (n = 4). Again, parturition was interrupted in three out of four saline-treated animals for at least 2.5 h, but resumed promptly when exogenous oxytocin was administered. Plasma concentrations of oxytocin in these pigs were significantly lower than in naloxone-treated pigs, five out of six of which gave birth spontaneously to one or more piglets within 2.5 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Pregnancy, labor and body image in the United States

Although substantial research has been done showing how alienation (which in Ollman's terms means that "an essential tie has been cut in the middle") manifests itself in the domain of human labor, little has been done to discover how similar processes might operate in other domains. I examine women's images of their bodies while they are pregnant, using Lakoff and Johnson's method of looking for metaphors that are presupposed in our ordinary language. I uncover several central images, all of which display a marked sense of separation of self from the parts of the body, and a passive stance in which events are described as happening to rather than being brought about by the speaker. Turning to written texts, I find that the literature on childbirth (from opposite ends of the spectrum--popular literature advocating prepared childbirth on one end and obstetrical texts for medical students on the other) holds an assumption in common: that the uterus is an involuntary muscle. This is so despite evidence to the contrary cited in the texts themselves. I explore the implications of this imagery for obstetrical treatment of 'uterine inertia' and show the similarity between this imagery and ideas about women's physiology that were current in the 19th century.

A randomized clinical trial of the Leboyer approach to childbirth

To examine the effects of the Leboyer method of delivery, we randomly assigned 56 women to either a Leboyer or a conventional delivery and used a variety of clinical and behavioral measures to assess the outcome in mother and child. No differences were noted in maternal or newborn morbidity, in infant behavior in the first hour of life, at 24 or 72 hours post partum, or at eight months of age; or in maternal perceptions of her infant and the experience of giving birth, except that eight months after delivery, mothers who had used the Leboyer method were more likely to say that the event had influenced their child's behavior (P = 0.05). Women who expected a Leboyer delivery had shorter active labors (P = 0.03), suggesting that psychologic factors (expectations) influence physical outcomes in perinatal medicine. Our results suggest that the Leboyer procedure has no advantage over a gentle, conventional delivery in influencing infant and maternal outcomes.

Obstetric and psychological effects of psychoprophylactic preparation for childbirth

Medical records, personal interviews about the childbirth experience, and self-administered attitudinal and socioeconomic data were obtained 1 to 3 days post partum in a large metropolitan hospital, for 249 women, 95 of whom had taken psychoprophylaxis training for childbirth prior to delivery. When controlled by parity, psychoprophylactic preparation was not related to any obstetric differences except for lower levels of anesthesia for both primiparas and multiparas and lower levels of analgesia among multiparas only. Preparation was significantly related to lower levels of pain and higher levels of enjoyment during childbirth, and these psychological benefits did not diminish when controlled for parity, socioeconomic status, and four sets of psychological and attitudinal characteristics.