Ferguson Reflex Research Articles

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.

3.33 Is Intrapartum Epidural Anesthesia Associated With Increased Synthetic Oxytocin Exposure and ASD?

Labor epidural anesthesia (LEA) can block the Ferguson reflex that stimulates maternal oxytocin release during labor. Thus, LEA can increase the need for synthetic oxytocin (sOT) exposure to augment labor. Recent research indicated an association of elevated OR of ASD with higher dose and longer duration of exposure to sOT. Consequently, this study examined possible associations between LEA, sOT dosing, and a diagnosis of ASD.

Overcoming Primary Cervical Dystocia with Ayurveda Therapeutic Strategy- Case Study

Background: We report a case of primary cervical dystocia managed successfully with Ayurveda therapy. The classical Ayurveda lexicons comprise detailed descriptions regarding Prasava (labor) and its management based on which the present case was intervened which resulted in achieving progressive improvement in cervical dilatation and achieving normal labor.
 Case Presentation: The case reported in this study is primigravidae, 25 years’ old visited prasutitantra OPD, NIA hospital with 37.2 weeks gestational age complaining of labor pains. Since her contraction and per vaginal findings were suggestive of onset of labor, she was hospitalized for further monitoring and awaited spontaneous progress of labor. Repeated Per vaginal examination revealed no progress in cervical dilatation even after 28 hours and she was diagnosed with primary cervical dystocia. Intervention of Kebuka taila yonipichu-25ml 2 hourly was made which resulted in remarkable cervical dilatation equivalent to mean standard rate following 3 interventions of yonipichu within 6 hours.
 Conclusion: The status of the cervix during labor is a significant determinant of mode and ease of labor. Ayurveda therapeutic strategy of Kebuka taila yoni-pichu can effectively prime the cervix due to the Garbhashayaka sankochaka and estrogenic properties of Kebuka and the activation of Ferguson's reflex by Yoni-pichu.

Benefit of oxytocin released by cervix stimulation in Mexican Holstein cattle

Objective:The aim of this research is to investigate the relationship level of oxytocin released and the tactile stimulation of the cervix in Holstein cattle from the northwestern arid regions in México.Materials and Methods:The cervixes of 10 Holstein Friesian dairy cows in mid-lactation were manually stimulated for 60 sec. Oxytocin released in the blood was analyzed before and after stimulation. The enzyme-linked immunosorbent assay was used in the analysis to make oxytocin detectable by spectrometry techniques and by converting the luminescence absorbance of each sample into pg per mol.Results:The study revealed that tactile stimulation of the cervix increased oxytocin levels. The highest increase in oxytocin level was 10,940.8222 pg/mol, while the lowest increase in oxytocin level was 1,830.94254 pg/mol. Besides, the milk production by tactile stimulation of the cervix had a higher milk yield and a p-value of 9.4 × 10−4 (p < 0.05) in comparison to the monthly average without tactile stimulation.Conclusion:Tactile stimulation of the cervix activates the Ferguson reflex and increases the oxytocin released in the blood and increases the milk released from the alveolar glands.

P-1456 - Neurobiologic correlates between sexual activity and women's mood

Introduction Vagino-cervical stimulation and orgasm may influence mood since sexual intercourse and orgasm physiologically stimulate the vagal nerve and increase the secretion of oxytocin. Objective To explain physiopathologic correlations between sexual intercourse and orgasm from one part and women's mood from another part. Methods A review of the literature published via MedLine is done without any restrictions, using the terms “vagino-cervical stimulation” or “orgasm” in association with “affect” or “mood” or “stress”. Results Vagal nerve bypasses the spinal cord in its course to the brain and constitute the afferent pathway stimulating orgasm. Vagal nerve stimulation is an adjunctive long-term treatment of chronic or recurrent depression. Epilepsy patients who have received vagal nerve stimulation have shown improvement in depressive symptoms. Vagal nerve stimulation may activate the release of oxytocin, noradrenalin and serotonin via the stimulation of the tractus solitaris. Vagino-cervical stimulation releases oxytocin into plasma via the Ferguson reflex. Oxytocin's origin is predominantly in neurons of the paraventricular nucleus of the hypothalamus that project axons into the posterior pituitary, where they release oxytocin into the systemic circulation in response to vagino-cervical stimulation and orgasm. Studies of brain imaging indicate increased activation at women's orgasm in the paraventricular nucleus of the hypothalamus, periaqueductal gray of the midbrain, hippocampus, and the cerebellum. There has been at least one clinical trial showing that daily intranasal oxytocin led to improvements in depressive symptoms and reactivity to stressful life events. Conclusion Orgasm and vagino-cervical stimulation affects mood level in women.

Oxytocin Plasma Levels in Cows with Normal Parturition or Dystocia and with Placental Retention*)

Plasma oxytocin level was determined by RIA in eight cows with normal parturition or with dystocia and retained foetal membranes. Both concentration and profile of oxytocin measured around parturition in cows with these disturbances were markedly changed, compared to the cows with the normal course of parturition. Oxytocin was released in the greatest amounts during physiological parturition or during parturition with dystocia in response to the Ferguson reflex only. In cows with dystocia lengthen of the period of the low oxytocin level was observed, though cervix was dilated. Then, it seems that some cases of placental retention are related to the low oxytocin level.

Comparaison de l’activité réflexe de l’utérus au cours de l’insémination artificielle et de l’accouplement chez la brebis

To identify and to compare the reflex mechanisms involved in the activation of the uterine motility following artificial insemination (AI) and mating in the ewe. The contractile activity of the uterus was monitored in presence and absence of adrenergic (phentolamine) and cholinergic (atropine) antagonists, using an implantable telemetric device equipped with a sensor catheter inserted into the uterine lumen, and connected to a radio-telemetric transmitter. During AI, a uterine contraction (UC) of short duration (<20 seconds) appeared in direct response to animal restraint, to the speculum introduction, then when the speculum was opened. Both the UC evoked by restraint of the ewe and insertion of the speculum were abolished in presence of phentolamine, while atropine inhibited the UC in response to opening of the speculum only. After AI, the uterine activity increased sharply and was all the more intense and extended with higher vaginal wall pressure. Phentolamine or atropine did not inhibit this motor response, whereas a similar pattern of uterine hyperactivity occurred following i.v. injection of oxytocin (100 and 200 mIU; Syntocinon). After mating, an increase in uterine activity was never observed. Only penis intromission evoked a UC of short duration (about 20 seconds), abolished in presence of phentolamine only. Artificial insemination in the ewe increases uterine motility, resulting from the reflex activation of adrenergic and cholinergic nerve fibres of the autonomic nervous system, following by a reflex release of oxytocin from the pituitary gland (also called "Ferguson reflex"). This secretion of OT was elicited by the excessive dilation of the vaginal wall with the speculum. By comparison, mating did not evoke a period of uterine hyperactivity and respects the physiological post-coital resting period.

Neural pathways mediating vaginal function: the vagus nerves and spinal cord oxytocin.

The initial observations, made in our laboratory with Knut Larsson, of the ability of vaginocervical stimulation (VCS) to block withdrawal responses to foot pinch in rats has led to findings of multiple behavioral, autonomic, and neuroendocrine effects of this potent stimulus in rats and also in women. It has led to an understanding of: (1) the neuroanatomical and neurochemical basis of a novel and potent pain-blocking mechanism; (2) likely neuroanatomical pathways mediating both the Ferguson reflex and a specific autonomic response - the pupil-dilating effect of VCS; (3) a role for oxytocin as a putative central nervous system neurotransmitter that stimulates autonomic sympathetic preganglionic neurons within the spinal cord; and (4) a novel pathway that can convey sensory activity from the cervix, adequate to induce orgasm, via the vagus nerves. This latter pathway bypasses the spinal cord and projects directly to the medulla oblongata, and thus can convey genital afferent activity despite complete spinal cord injury at any level.

Pelvic neurectomy abolishes the fetus-expulsion reflex and induces dystocia in the rat

To clarify the origin of dystocia in bilaterally pelvic neurectomized (BPN) rats, the uterine activity during the periparturient period, and reflex straining movements in response to vaginal stimulation and cervical extensibility were monitored. The BPN rat displayed “stretching” movements and the regular continuous uterine activity with a similar onset and intensity to that in control rats (intact, sham-operated or unilateral pelvic neurectomized rats) on days 22 or 23 of gestation, but lacked the “straining” movements which precede each delivery of pups in controls so that parturition was prolonged. Dissection of rats revealed that an unborn fetus was retained in the expanded upper portion of the vaginal cavity. Vaginal distension induced contraction of the abdominal muscles and diaphragm and an inhibition of respiratory movements, resulting in an increase in intraabdominal pressure in urethane-anesthetized control rats. This reflex muscular contraction which reflects the straining movements in normal delivery may be called the fetus-expulsion reflex and does not occur in BPN rats. It differs from the fetus-ejection reflex (Ferguson reflex) which initiates oxytocin release. There was no difference in weight and distensibility of the uterine cervix between sham-operated and operated rats on day 22 of pregnancy. The results suggest that the main abnormality of delivery in BPN rats, a prolongation of the process of delivery, may be due to a lack of the fetus-expulsion reflex which plays a physiologic role in removing a fetus from the upper vaginal cavity against the resistance of the pelvic outlet.

Oxytocin release during parturition in the pelvic-neurectomized rat

Blood levels of oxytocin during parturition in pelvic-neurectomized rats were determined by radioimmunoassay. Four out of 29 pelvic-neurectomized rats completed parturition within 23 days of pregnancy. These rats exhibited an increase in blood levels of oxytocin during parturition similar to those of shamoperated control rats, but delivery took longer and there was a higher percentage of still-births. The rise in blood levels of oxytocin was smaller in the 16 rats in which the first fetus was expelled but where delivery did not end within day 23 of gestation than that in sham-operated controls. Levels did not increase in the other nine rats which failed to deliver the first fetus within 23 days of pregnancy. They did, however, show signs indicating delivery, such as stretch movements, vaginal bleeding and/or excretion of mucus within 23 days of gestation. Oxytocin infusion (2 mu./min) for 2-4 h increased uterine contractions in the pelvic-neurectomized rats but failed to reduce the percentage of still-births or the duration of delivery. Immunoneutralization of circulating oxytocin by anti-oxytocin serum in intact pregnant rats resulted in a significant but much smaller prolongation of the duration of delivery compared with that observed in pelvic-neurectomized rats. The rise in blood levels of oxytocin during pregnancy may be induced, at least in part, by the Ferguson reflex via the pelvic nerve and may thus facilitate the process of delivery. A shortage of oxytocin secretion may not, however, be the main cause of the dystocia in pelvic-neurectomized rats.

Spurt release of oxytocin during surgical induction of labor in women

Oxytocin levels were measured in closely spaced samples of maternal blood from 10 women who underwent amniotomy for induction of labor. The procedure was associated with a spurt release of oxytocin, the highest frequency being found during sweeping and rupture of the membranes. It was concluded that the main stimulus to this release was vaginal distention (Ferguson's reflex) and that the same mechanism probably accounts for the increase in maternal oxytocin during the expulsive phase of labor.

Effects of Dopaminergic Antagonist and Agonist on Oxytocin Release Induced by Various Stimuli

(1) Haloperidol, a dopaminergic antagonist was injected i.p. or into the 3rd ventricle (i.c.v.) of lactating rats to determine whether or not a dopaminergic component was involved in the reflex release of oxytocin (OT) induced by (a) vaginal dilatation (Ferguson reflex), (b) vagal stimulation (vago-pituitary reflex), (c) suckling (milk-ejection reflex). Moreover, we examined the effect of a dopaminergic agonist, apomorphine, on the milk-ejection (ME) reflex. (2) I.c.v. injection of 20 microgram haloperidol inhibited the vaginal and vagal reflexes. The inhibition of the ME reflex produced by 2, 5 or 8 mg/kg i.p. or by 20 and 40 microgram i.c.v. haloperidol was dose-dependent. Apomorphine (10 mg/kg i.p.) had no effect. (3) The results suggest that a dopaminergic component must be involved in OT release whatever the peripheral stimulus.

Blockade of the Ferguson reflex by lumbar epidural anaesthesia in the parturient sheep: effects on oxytocin secretion and uterine venous prostaglandin F levels.

The role of oxytocin in the increase in utero-ovarian venous prostaglandin F (PGF) level caused by vaginal distension was investigated by using lumbar epidural anaesthesia to block the oxytocin secretion reflex. Whereas vaginal distension raised jugular venous oxytocin and utero-ovarian venous PGF levels in untreated sheep, neither response occurred after lumbar anaesthesia. Lumbar anaesthesia had no effect on the rise in utero-ovarian venous PGF level caused by administered oxytocin. These findings support the suggestion that a reflex release of oxytocin is involved in the elevation of utero-ovarian venous PGF observed after vaginal distension in parturient sheep.

Maternal Hypothalamic Control of Labor

This chapter focuses on the maternal hypothalamic control of labor. Three links between the maternal hypothalamus and the uterine contractions of labor can be established—namely, (1) anterior pituitary, ovary, estrogen and progesterone, (2) posterior pituitary, oxytocin and the Ferguson reflex, (3) autonomic nervous system, catecholamines and stress. The contractions of the uterus, as expressed in labor, are subject to a variety of physical, hormonal and neural constraints. Hippocrates expressed remarkable foresight on postulating a role for the fetus in the organization of birth. The physical task of delivering the young is still the prerogative of the mother. The role of mother is far from “passive” and control is exercised to determine the exact hour of birth on that final day of gestation. Such dual control embodies a most sound rationale. The fetus is the best judge of its own maturity (or viability); the mother has the faculties to assess the environmental factors which will govern survival at the time of birth.

Elimination of the Ferguson reflex by section of the pelvic nerves in the lactating goat.

SUMMARY Distension of the vagina by an inflated balloon induces milk ejection in goats. This reflex (the Ferguson reflex) is based on a neurohormonal mechanism. In three goats the reflex was abolished after bilateral section of the complex pelvic nerves plus caudal rectal nerves. Bilateral section of the pelvic nerves only, caused a complete elimination of the reflex in 11 out of 13 goats; in the two remaining animals, the reflex was abolished after a supplementary section of the pudendal nerve plus caudal rectal nerves. The reflex remained intact in one goat in which first the caudal rectal nerves and subsequently the pudendal nerve were cut. Elimination of the Ferguson reflex was accompanied by a marked reduction of the intensity of straining movements which are normally induced by distension of the vagina. Bilateral section of the pelvic nerves provoked a severe but temporary paralysis of the large intestine with blocking of the defaecation reflex. It is suggested that in ruminants the afferent pelvic nerves are involved in the release of oxytocin and in the intense straining occurring during the phase of expulsion at parturition.