The Ferguson reflex (also called the fetal ejection reflex) is the neuroendocrine reflex comprising the self-sustaining cycle of uterine contractions initiated by pressure at the cervix, more precisely, the internal end of cervix, or vaginal walls. It is an example of positive feedback in biology. The Ferguson reflex occurs in mammals.
Upon application of pressure to the internal end of the cervix, oxytocin is released (therefore increase in contractile proteins), which stimulates uterine contractions, which in turn increases pressure on the cervix (thereby increasing oxytocin release, etc.), until the baby is delivered.
Sensory information regarding mechanical stretch of the cervix is carried in a sensory neuron, which synapses in the dorsal horn before ascending to the brain in the anterolateral columns (ipsilateral and contralateral routes). Via the medial forebrain bundle, the efferent reaches the PVN and SON of the hypothalamus. The posterior pituitary releases oxytocin due to increased firing in the hypothalamo-hypophyseal tract. Oxytocin acts on the myometrium, on receptors which have been upregulated by a functional increase of the estrogen-progesterone ratio. This functional ratio change is mediated by a decrease in myometrial sensitivity to progesterone, due to a decrease in progesterone receptor A, and a concurrent increase in myometrial sensitivity to estrogen, due to an increase in estrogen receptor α. This causes myometrial contraction and further positive feedback on the reflex. [1] [2]
In their studies among mice, Niles Newton and colleagues demonstrated the importance of cortical influences. [3] They enlarged the topic by introducing the term fetus ejection reflex.
The concept of cortical influences provided reasons to raise questions about the process of parturition among humans, characterized by a high encephalization quotient. Michel Odent had observed that women can experience such a reflex, characterized by a birth after a short series of irresistible and powerful contractions without any room for voluntary movements, resulting in a painless birth. For such a hormonal cascade to occur requires sufficient psychological safety, as occurs in normal or undisturbed birth. The higher the intervention rate, such as induction or caesarian section, the lower the likelihood of the Ferguson Reflex occurring. In contrast, the lower the incidence of intervention, such as is found in those countries with high rate of home births Archived 2020-11-11 at the Wayback Machine , and birth centers worldwide, the higher the likelihood of the Ferguson Reflex occurring. This may explain the lack of research, considering the public health benefits of such education to both hospitals and the general public.
The endometrium is the inner epithelial layer, along with its mucous membrane, of the mammalian uterus. It has a basal layer and a functional layer: the basal layer contains stem cells which regenerate the functional layer. The functional layer thickens and then is shed during menstruation in humans and some other mammals, including other apes, Old World monkeys, some species of bat, the elephant shrew and the Cairo spiny mouse. In most other mammals, the endometrium is reabsorbed in the estrous cycle. During pregnancy, the glands and blood vessels in the endometrium further increase in size and number. Vascular spaces fuse and become interconnected, forming the placenta, which supplies oxygen and nutrition to the embryo and fetus. The speculated presence of an endometrial microbiota has been argued against.
Uterine contractions are muscle contractions of the uterine smooth muscle that can occur at various intensities in both the non-pregnant and pregnant uterine state. The non-pregnant uterus undergoes small, spontaneous contractions in addition to stronger, coordinated contractions during the menstrual cycle and orgasm. Throughout gestation, the uterus enters a state of uterine quiescence due to various neural and hormonal changes. During this state, the uterus undergoes little to no contractions, though spontaneous contractions still occur for the uterine myocyte cells to experience hypertrophy. The pregnant uterus only contracts strongly during orgasms, labour, and in the postpartum stage to return to its natural size.
The endocrine system is a network of glands and organs located throughout the body. It is similar to the nervous system in that it plays a vital role in controlling and regulating many of the body's functions. Endocrine glands are ductless glands of the endocrine system that secrete their products, hormones, directly into the blood. The major glands of the endocrine system include the pineal gland, pituitary gland, pancreas, ovaries, testicles, thyroid gland, parathyroid gland, hypothalamus and adrenal glands. The hypothalamus and pituitary glands are neuroendocrine organs.
Atosiban, sold under the brand name Tractocile among others, is an inhibitor of the hormones oxytocin and vasopressin. It is used as an intravenous medication as a labour repressant (tocolytic) to halt premature labor. It was developed by Ferring Pharmaceuticals in Sweden and first reported in the literature in 1985. Originally marketed by Ferring Pharmaceuticals, it is licensed in proprietary and generic forms for the delay of imminent preterm birth in pregnant adult women.
Adenomyosis is a medical condition characterized by the growth of cells that proliferate on the inside of the uterus (endometrium) atypically located among the cells of the uterine wall (myometrium), as a result, thickening of the uterus occurs. As well as being misplaced in patients with this condition, endometrial tissue is completely functional. The tissue thickens, sheds and bleeds during every menstrual cycle.
Bloody show or show is the passage of a small amount of blood or blood-tinged mucus through the vagina near the end of pregnancy. It is caused by thinning and dilation of the cervix, leading to detachment of the cervical mucus plug that seals the cervix during pregnancy and tearing of small cervical blood vessels, and is one of the signs that labor may be imminent. The bloody show may be expelled from the vagina in pieces or altogether and often appears as a jelly-like piece of mucus stained with blood. Although the bloody show may be alarming at first, it is not a concern of patient health after 37 weeks gestation.
The hypothalamic–pituitary–gonadal axis refers to the hypothalamus, pituitary gland, and gonadal glands as if these individual endocrine glands were a single entity. Because these glands often act in concert, physiologists and endocrinologists find it convenient and descriptive to speak of them as a single system.
The menstrual cycle is on average 28 days in length. It begins with menses during the follicular phase, followed by ovulation and ending with the luteal phase. While historically, medical experts believed the luteal phase to be relatively fixed at approximately 14 days, recent research suggests that there can be wide variability in luteal phase lengths not just from person to person, but from cycle to cycle within one person. The luteal phase is characterized by changes to hormone levels, such as an increase in progesterone and estrogen levels, decrease in gonadotropins such as follicle-stimulating hormone (FSH) and luteinizing hormone (LH), changes to the endometrial lining to promote implantation of the fertilized egg, and development of the corpus luteum. In the absence of fertilization by sperm, the corpus luteum degenerates leading to a decrease in progesterone and estrogen, an increase in FSH and LH, and shedding of the endometrial lining (menses) to begin the menstrual cycle again.
Prostaglandin E2 (PGE2), also known as dinoprostone, is a naturally occurring prostaglandin with oxytocic properties that is used as a medication. Dinoprostone is used in labor induction, bleeding after delivery, termination of pregnancy, and in newborn babies to keep the ductus arteriosus open. In babies it is used in those with congenital heart defects until surgery can be carried out. It is also used to manage gestational trophoblastic disease. It may be used within the vagina or by injection into a vein.
Uterine atony is the failure of the uterus to contract adequately following delivery. Contraction of the uterine muscles during labor compresses the blood vessels and slows flow, which helps prevent hemorrhage and facilitates coagulation. Therefore, a lack of uterine muscle contraction can lead to an acute hemorrhage, as the vasculature is not being sufficiently compressed. Uterine atony is the most common cause of postpartum hemorrhage, which is an emergency and potential cause of fatality. Across the globe, postpartum hemorrhage is among the top five causes of maternal death. Recognition of the warning signs of uterine atony in the setting of extensive postpartum bleeding should initiate interventions aimed at regaining stable uterine contraction.
Carbetocin, sold under the brand names Pabal among others, is a medication used to prevent excessive bleeding after childbirth, particularly following Cesarean section. It appears to work as well as oxytocin. Due to it being less economical than other options, use is not recommended by NHS Scotland. It is given by injection into a vein or muscle.
Prostaglandin F2α, pharmaceutically termed dinoprost, is a naturally occurring prostaglandin used in medicine to induce labor and as an abortifacient. Prostaglandins are lipids throughout the entire body that have a hormone-like function. In pregnancy, PGF2α is medically used to sustain contracture and provoke myometrial ischemia to accelerate labor and prevent significant blood loss in labor. Additionally, PGF2α has been linked to being naturally involved in the process of labor. It has been seen that there are higher levels of PGF2α in maternal fluid during labor when compared to at term. This signifies that there is likely a biological use and significance to the production and secretion of PGF2α in labor. Prostaglandin is also used to treat uterine infections in domestic animals.
Lactation describes the secretion of milk from the mammary glands and the period of time that a mother lactates to feed her young. The process naturally occurs with all sexually mature female mammals, although it may predate mammals. The process of feeding milk in all female creatures is called nursing, and in humans it is also called breastfeeding. Newborn infants often produce some milk from their own breast tissue, known colloquially as witch's milk.
A uterotonic, also known as an oxytocic or ecbolic, is a type of medication used to induce contraction or greater tonicity of the uterus. Uterotonics are used both to induce labor and to reduce postpartum hemorrhage.
Placental expulsion occurs when the placenta comes out of the birth canal after childbirth. The time between the expulsion of the baby and the expulsion of the placenta is called the third stage of labor.
Prolonged labor is the inability of a woman to proceed with childbirth upon going into labor. Prolonged labor typically lasts over 20 hours for first time mothers, and over 14 hours for women that have already had children. Failure to progress can take place during two different phases; the latent phase and active phase of labor. The latent phase of labor can be emotionally tiring and cause fatigue, but it typically does not result in further problems. The active phase of labor, on the other hand, if prolonged, can result in long term complications.
Nipple stimulation or breast stimulation is stimulation of the breast. Stimulation may be by breastfeeding, sexual activity, an indirect non-sexual response, or kissing the nipple. As part of sexual activity, the practice may be performed upon, or by, people of any gender or sexual orientation. It may occur with the use of fingers, orally, such as by sucking or licking, as well as by use of an object.
Pain management during childbirth is the partial treatment and a way of reducing any pain that a woman may experience during labor and delivery. The amount of pain a woman feels during labor depends partly on the size and position of her baby, the size of her pelvis, her emotions, the strength of the contractions, and her outlook. Tension increases pain during labor. Virtually all women worry about how they will cope with the pain of labor and delivery. Childbirth is different for each woman and predicting the amount of pain experienced during birth and delivery can not be certain.
Sarah K. England is a physiologist and biophysicist and the Alan A. and Edith L. Wolff Professor of Obstetrics and Gynaecology at Washington University School of Medicine. England conducts research on cation channels in uterine smooth muscle to understand the biological correlates of preterm birth and is the Associate Program Director of the Prematurity Research Center at Washington University as well as the Vice Chair of Research for the Center for Reproductive Health Sciences. In 2005, England was selected as a Robert Wood Johnson Foundation Health Policy Fellow in the Office of Senator Hillary Clinton where she used her scientific expertise in obstetrics and gynaecology to guide policy changes.
Hormones during pregnancy are the result of an intricate interaction between hormones generated by different glands and organs. The primary hormones involved comprise human chorionic gonadotropin (hCG), progesterone, estrogen, human placental lactogen (hPL), and oxytocin. Hormones are synthesized in certain organs, including the ovaries, placenta, and pituitary gland. These hormones have essential functions in pregnancy test, maintaining the uterine lining, fetal development, preventing premature labor, and the initiation and support of labor.