Positive Health Online

Gentle and Natural Birth Induction Part I was published in PH Online Jan 2011 Issue 178 - www.positivehealth.com/article-view.php?articleid=2946  

The Role of Hormones: Background Reading and Supporting Theories may be found at www.childbirthconnection.org/article.asp?ck=10184  

Oxytocin

Oxytocin is also called the love-hormone'. It is best known for its role in inducing labour and its influence on the ability to connect with others, according to researchers at the University of California, San Francisco. (www.oxytocin.org/oxytoc/index.html)

When the newborn is placed on the mother 'skin to skin' after the birth, oxytocin levels increase and facilitate bonding with the infant. Oxytocin stimulates milk ejection during lactation, uterine contraction during birth, and is released during sexual orgasm in both men and women. Receptor cells allowing a woman's body to respond to oxytocin increase gradually in pregnancy, and then sharply in labour.

Oxytocin is a potent stimulator of contractions, which helps dilate the cervix, moves the baby down and out of her body, give birth to her placenta, and limit bleeding at the site of the placenta. During labour and birth, the pressure of the baby against the cervix and then against tissues in the pelvic floor stimulates oxytocin and contractions.

Oxytocin levels gradually increase and peak around birth, saturating the mother and baby with love. Nipple stimulation during labour, massage or any other touch therapy and suckling of the newborn can increase the level of oxytocin. Oxytocin release during breastfeeding causes mild but often painful uterine contractions during the first few weeks of lactation, and helps in the 'let down' of the milk from the mammary glands. It is also released during orgasm in both sexes. Oxytocin can contribute to an incapacitated mind, as can endorphins and high level of oestrogens.

Low levels of oxytocin during labour and birth can cause problems by:

• Causing contractions to stop or slow, and lengthening labour;
• Resulting in excessive bleeding at the placenta site after birth.

A woman can help promote her body's production of oxytocin during labour and birth by:

• Staying calm, cool and collected;
• Avoiding disturbances, such as unwelcome people or noise and uncomfortable procedures;
• Staying upright and using gravity to apply pressure of her baby against her cervix and then, as the baby is born;
• Engaging in nipple stimulation giving her baby a chance to suckle shortly after birth.

Endorphins (www.childbirthconnection.org/article.asp?ck=10184)

Endorphins are brain chemicals known as neurotransmitters produced in the brain, spinal cord, and other parts of the body. They are released in response to neurotransmitters and bind to certain neuron receptors (the same ones that bind opiate medicines). Endorphins diminish perception of pain and can act as sedatives.

Stress and pain are the two most common factors leading to the release of endorphins and are similar to opiates in their action as painkillers and inducing a feeling of 'high'. In addition to decreased feelings of pain, the secretion of endorphins leads to feelings of euphoria, modulation of appetite, release of sex hormones, and enhancement of the immune response. They are also responsible for the spatial memory loss and forgetfulness during pregnancy and after birth.

With high endorphin levels, we feel less pain and fewer negative effects of stress. It is known that the body produces endorphins in response to prolonged, continuous physical exercise or exertion, such as birth for example and manual treatments, such as massage or reflexology. The level of this natural morphine-like substance may rise toward the end of pregnancy, and then rises steadily and steeply during un-medicated labour.

High endorphin levels during labour and birth can produce an altered state of consciousness that helps women flow with the process, even when it is long and arduous. Endorphins disinhibit the dopamine pathways, causing more dopamine to be released. Despite the hard work of labour and birth, a woman with high endorphin levels can feel alert, attentive, and even euphoric as she begins to get to know and care for her baby after birth. Alertness is also due to increased adrenalin level which rises towards the end of labour.

Endorphins too may play a role in strengthening the mother-infant relationship. A drop in endorphin levels in the days after birth may contribute to the 'blues' that some women experience at this time.

Low levels of endorphin can cause problems in labour and birth by:

• Causing labour to be excessively painful;
• A feeling of the pain being intolerable.

A woman can enhance her body's production of endorphins during labour and birth by:

• Staying cool, calm and collected;
• Avoiding disturbances, such as unwelcome people or noise and uncomfortable procedures.

Interesting:

Certain foods, such as chocolate or chilli peppers, can also lead to enhanced secretion of endorphins. In the case of chilli peppers, the spicier the pepper, the more endorphins are secreted. The release of endorphins upon ingestion of chocolate explains the comforting feelings that many people associate with this food and the craving for chocolate in times of stress.

Adrenalin (www.childbirthconnection.org/article.asp?ck=10184)

Adrenalin is the hormone of excitement and it can also stimulate the 'fight or flight' response in the sympathetic nervous system. Adrenaline, the 'fight or flight' hormone helps ensure survival. Women who feel threatened during labour (for example by fear, severe pain or by unwelcome people) may produce high levels of adrenaline. Adrenaline can slow labour or stop it altogether. Earlier in human evolution, this disruption helped birthing women move to a place of greater safety.

During transition, adrenalin levels increase to trigger the foetal ejection reflex and supply the mother with a rush of energy to come out of her altered state of awareness. Together with high levels of oxytocin, this will bring on strong contractions that urge the mother to bear down and birth her baby easily and quickly. This hormone too assists with the bonding of mother and child.

A woman can keep adrenaline down during labour and birth by staying calm, comfortable, and relaxed. The following can help:

• Being informed and prepared;
• Having trust and confidence in her body and her capabilities as a birthing woman;
• Having trust and confidence in her caregivers and birth setting;
• Being in a calm, peaceful, and private environment and avoiding conflict;
• Being with people who help her with comfort measures, good information, positive words, and other support;
• Avoiding intrusive, painful and disruptive procedures.

Too much adrenalin can cause problems in labour and birth by:

• Causing distress to the unborn baby;
• Causing contractions to stop, slow, or have an erratic pattern, and lengthening labour;
• Creating a sense of panic and increasing pain in the mother.

Interesting

The fact that adrenaline and oxytocin are antagonistic explains the basic need of all mammals when giving birth to feel secure. In a wild environment a female cannot give birth as long as there is a possible danger; for example the presence of a predator around. In that case it is an advantage to release adrenaline, which brings more blood to the skeletal muscles and gives more energy to fight or to run away; it is also an advantage to stop releasing oxytocin and to postpone the birth process.

There is in fact a great diversity of situations associated with a release of adrenaline. Mammals release adrenaline when they feel observed. It is noticeable that they all rely on a specific strategy not to feel observed when giving birth; privacy is obviously another basic need.

The emergency hormone is also involved in thermo-regulation. In a cold environment one of the well-known roles of adrenaline is to induce vasoconstriction. This explains that, for the act of birthing, mammals must be in a place that is warm enough.

Prolactin (www.childbirthconnection.org/article.asp?ck=10184)

Prolactin is the hormone of mothering; it peaks at the time before birth. It prepares the woman for motherhood and helps her to feel loving and tender towards her baby.

Interesting: The prolactin levels show a fall during labour, and this was more marked where stress was evident. The concentrations of cortisol also tended to increase during labour and reach a maximum at delivery. These results give further support to the hypothesis that maternal stress leads to a reduced concentration of prolactin and increased concentration of cortisol.

Prolactin is the hormone of breast milk and is considered to be imperative for optimal brain development in the new born baby. During pregnancy, high circulating concentrations of oestrogen promote prolactin production. The resulting high levels of prolactin secretion cause further maturation of the mammary glands, preparing them for lactation.

Another effect, recently discovered by the University of Paisley and the Technische Hochschule Zürich,( www.medic8.com) is to provide the body with sexual gratification after sexual acts. The hormone represses the effect of dopamine, which is responsible for sexual arousal, thus inducing the male's refractory period. The amount of prolactin can be an indicator for the amount of sexual satisfaction and relaxation.

After childbirth, prolactin levels fall as the internal stimulus for them is removed. Sucking by the baby on the nipple then promotes further prolactin release, maintaining the ability to lactate. The sucking activates mechano-receptors in and around the nipple. These signals are carried by nerve fibres to the pituitary gland, which causes increased prolactin secretion. The suckling stimulus also triggers the release of oxytocin from the posterior pituitary gland, which triggers milk let-down. Prolactin controls milk production (lactogenesis) but not the milk-ejection reflex; the rise in prolactin fills the breast with milk in preparation for the next feed.

Oestrogen (www.sciencedaily.com)

Oestrogen regulates progesterone, a hormone that protects the continuation of pregnancy. Oestrogen also kick-starts one of the major processes of foetal maturation; without it, a foetus' lungs, liver and other organs and tissues cannot mature. During pregnancy there is an increased level of progesterone which prevents the uterus from contracting, which helps in the gestation of the foetus.

When the woman approaches her due date, oestrogen levels increase and top progesterone level. The uterus becomes more receptive towards circulating oxytocin which both the baby and the mother produce in response to each other. Also, prostaglandins are active towards the due date which helps soften the cervix and ligaments to facilitate birth. Oestrogens increase throughout pregnancy, and are produced primarily by the placenta. Among other functions, oestrogens increase uterine blood flow. The production of prolactin is thought to be stimulated by increasing levels of oestrogens.

Prostaglandins

Prostaglandins were first discovered and isolated from human semen in the 1930s by Ulf von Euler of Sweden. (www.elmhurst.edu). Thinking they had come from the prostate gland, he named them prostaglandins. Prostaglandins are highly potent substances that are not stored, but are produced as needed by cell membranes in virtually every body tissue. Prostaglandins, are like hormones in that they act as chemical messengers, but do not move to other sites, but work right within the cells where they are synthesized. Different prostaglandins have been found to raise or lower blood pressure and regulate smooth muscle activity and glandular secretion.

Several prostaglandins have been shown to induce fever, possibly by participating in the temperature-regulating mechanisms in the hypothalamus. Prostaglandins are involved in the activation of the inflammatory response, production of pain, and fever. When tissues are damaged, white blood cells flood to the site to try to minimize tissue destruction. Prostaglandins are produced as a result.

Blood clots form when a blood vessel is damaged. A type of prostaglandin called thromboxane stimulates constriction and clotting of platelets. Conversely, PGI2, is produced to have the opposite effect on the walls of blood vessels where clots should not be forming.

Certain prostaglandins are involved with the induction of labour and other reproductive processes. PGE2 causes uterine contractions and has been used to induce labour. Prostaglandins are involved in several other organs such as the gastrointestinal tract (inhibit acid synthesis and increase secretion of protective mucus), increase blood flow in kidneys, and leukotrienes promote constriction of bronchi associated with asthma.

The relevant parts of the brain are the following:

1. Neo-cortex, (neopallium): rational, intellectual part of brain;
2. Intermediated brain, limbic system (paleopallium): emotional part of brain;
3. Primitive (primal) brain (archipallium): self preservation and aggression instinctual reactions.

The Primitive Brain and the Neo-cortex Balance (http://wombecology.com)

The primal brain is an ancient structure responsible for:

• Automatic functions;
• Symbols (e.g. stories);
• Emotions;
• Senses;
• Hormones;
• Safety and protection.

In basic terms the brain can be divided into two parts; the neo-cortex or new brain, which is the part that makes us human and the hypothalamus or primal brain, which directs our instinctive behaviour. This old brain is what we share with animals, and it is our animal nature that must be respected for birth.

The primitive brain can override the neo-cortex; its development was completed long before the neo-cortex - the thinking, newer part of the brain - developed. The primal brain is the main player in labour and must take precedence over the neo-cortex in order to ensure the whole process is as safe as possible for the mother and her baby.

During labour the primitive brain releases the hormones mentioned above.

• Oxytocin is secreted by the posterior pituitary gland but produced in the primal brain;
• Endorphins are secreted by the anterior pituitary gland;
• Adrenalin is secreted by the adrenal which is stimulated by the anterior pituitary gland and also the placenta;
• Prolactin is secreted by the anterior pituitary;
• Oestrogen is secreted by the gonads which in turn are stimulated by the anterior pituitary gland;
• Prostaglandin is secreted in the uterus and other organs.

The hormones secreted by the posterior pituitary (like oxytocin) are actually produced in the brain and carried to the pituitary gland through nerves. They are stored in the pituitary gland. During labour the primal brain sends out endorphins to calm the woman and switch off her neo-cortex. When the birthing woman ignores this or 'fights' against it by talking, trying to maintain a social presence, or tensing up with each surge, worries excessively and becomes frightened, the primal brain picks up on this as a danger and gets very alert and agitated. It then reduces the secretion of endorphins and increases stimulation of adrenalin secretion to activate the FFF response.

Adrenalin is also called the emergency hormone whose effect is to stop the release of oxytocin particularly when there is a possible danger. This interferes with the process of birth and tends to slow it down and prolong it, often stopping it altogether. It can also reduce the blood supply to the uterus, putting the baby at risk and into distress, which often results in a forceps delivery or emergency caesarean.

Odent (http://wombecology.com/homo.html) describes the importance of creating an environment that reduces activity to the neocortex and enhances the ability of the primitive brain to take over the process of birth. Like other primitive functions such as sleeping and sexual intercourse, the primitive brain controls birth. Activities such as talking, bright lights, and being observed, all stimulate the neocortex. This, in turn, inhibits the ability of the woman's body to produce the hormonal levels she needs for a normal birth.

The aim of any birth induction is to subdue the neo-cortex and reassure the primal brain that all is well, that there is no danger, and to help the mother surrender to the birthing process and just let go.
A birthing mother needs to feel private, safe and undisturbed so she can enter into an altered state of awareness and allow her birthing instincts to effortlessly unfold.

A doula can do a lot to help the neo-cortex switch off by using touch, music, aroma therapy, warmth, and security, and thus send messages of calm and safety to the primal brain. A woman who feels safe and comfortable is then able to 'let go'. Quiet, peaceful music or sounds and a darkened room will provide optimal conditions under which the primal brain will allow labour to start and continue.

Touch is one of the best approaches a doula can use to subdue the neo-cortex and communicate to the primal brain that all is well. When touch is used appropriately, endorphins are released which enhance the birthing woman's ability to relax. Feeling warm and nurtured also plays a key role in the quality of the birthing process. Having access to warm socks and blankets is of utmost importance, as shivering from feeling cold releases adrenalin. It is vital that the mother drinks regularly, and if she feels hungry, she needs to be able to eat.

Smells also play an important part in the birthing process. Smells that are comforting such as essential oils, or familiar such as pillows or blankets from home, are important when a woman is birthing in a hospital situation. It's all about creating a safe nest for the mother to birth in.

Though it is important to keep quiet and talk as little as possible in order to help keep the neo-cortex subdued, we sometimes have to talk to the birthing woman. This is not a problem, as long as we keep it simple and brief and don't get into long-winded discussions. It is advisable not to talk during a surge, except to give simple encouragement in a soothing tone.

The Limbic System

Buried within the depths of the cerebrum are several aggregates of the limbic structures and nuclei which control and mediate memory, emotion, learning, dreaming, attention, and arousal, and the perception and expression of emotional, motivational, sexual, and social behaviour including the formation of loving attachments.

The limbic system not only controls the capacity to experience love and sorrow, but it governs and monitors internal homeostasis and basic needs such as hunger and thirst. Over the course of evolution a layer of neo-cortex began to develop and enshroud the limbic system, to maximize the survival of the organism, and to more efficiently, effectively, and safely satisfy limbic needs and impulses. In consequence, the frontal, temporal, parietal, and occipital lobes evolved covered with a neocortical cover, associated with the conscious, rational mind.

The hypothalamus could be considered the most 'primitive' aspect of the limbic system. The hypothalamus regulates internal homeostasis including the experience of hunger and thirst, can trigger rudimentary sexual behaviours or generate feelings of extreme rage or pleasure.
In conjunction with the pituitary the hypothalamus is a major manufacturer/secretor of hormones and other bodily secretions, including those involved in the stress response and feelings of depression.

Cardinal Movements in Labour (www.birthsource.com)

The mechanisms of labour, also known as the cardinal movements, refer to the changes in position of foetal head during its passage through the birth canal. Because of the asymmetry of the shape of both the foetal head and the maternal bony pelvis, such rotations are required for the foetus to successfully negotiate the birth canal. Although labour and birth is a continuous process, seven discrete cardinal movements of the foetus are described: engagement, descent, flexion, internal rotation, extension, external rotation or restitution, and expulsion.

Descent

The baby's head moves deep into the pelvic cavity. This movement, commonly called lightening, is preceded by Engagement or the entering of the biparietal diameter (measuring ear tip to ear tip across the top of the baby's head) into the pelvic inlet. The baby's head becomes markedly molded when these distances are closely the same. When the occiput is at the level of the ischial spines, it can be assumed that the biparietal diameter is engaged and then descends into the pelvic inlet

Flexion

This movement occurs during descent and is brought about by the resistance felt by the baby's head against the soft tissues of the pelvis. The resistance brings about a flexion in the baby's head so that the chin meets the chest. The smallest diameter of the baby's head (or suboccipitobregmatic plane) presents into the pelvis.

Internal Rotation

As the head reaches the pelvic floor, it typically rotates to accommodate for the change in diameters of the pelvis. At the pelvic inlet, the diameter of the pelvis is widest from right to left. At the pelvic outlet, the diameter is widest from front to back. So the baby must move from a sideways position to one where the sagittal suture is in the anteroposterior diameter of the outlet (where the face of the baby is against the back of the labouring woman and the back of the baby's head is against the front of the pelvis). If anterior rotation does not occur, the occiput (or head) rotates to the occipitoposterior position. The occipitoposterior position is also called persistent occipitoposterior and is the common cause for true back labour.

Extension

After internal rotation is complete and the head passes through the pelvis at the nape of the neck, a rest occurs as the neck is under the pubic arch. Extension occurs as the head, face and chin are born.

External Rotation

After the head of the baby is born, there is a slight pause in the action of labour. During this pause, the baby must rotate so that his/her face moves from face-down to facing either of the labouring woman's inner thighs. This movement, also called restitution, is necessary as the shoulders must fit around and under the pubic arch.

Expulsion

Almost immediately after external rotation, the anterior shoulder moves out from under the pubic bone (or symphysis pubis). The perineum becomes distended by the posterior shoulder which is then also born. The rest of the baby's body is then born, with an upward motion of the baby's body by the care provider.

The Importance of the Psoas Muscle (http://somatics.com/psoas.htm) 

  
Anatomically, the psoas is a large muscle, measuring 16 inches in length and basically anchors the leg to the trunk.

• It starts at the front of the spinal vertebra T12;
• It attaches along the respiratory diaphragm and lumbar vertebrae from L1 to L5;
• It meets up with the iliacus muscle of the pelvic bowl;
• It dives under the groin to finally insert on the inner thighbone, thus influencing the movement and rotation of the pelvis.

Essentially, all the organs are in contact, either directly or indirectly, with the diaphragm and psoas.

Function

The psoas bends the hip and leg towards the chest when going up and down stairs and helps propel the leg forward when walking or running. It flexes the trunk forward when squatting or bending over. Fundamentally, it acts like a guide wire to stabilize the trunk and spine during movement and sitting. It correctly balances the abdominal and low back muscles ensuring erect posture.

The psoas supports the internal organs and functions as a hydraulic pump. Its movement allows for fluids to be pushed in and out of cells, such as blood and lymph.

When the fear reflex gets activated, the psoas flexes the hip. This can be observed when an infant becomes startled, the legs fly up towards its face instinctively to protect itself. As the child grows into adulthood, this reflex gets integrated. Instead of legs moving towards the face, now the trunk flexes toward the legs. During times of stress when in self-protection mode, the psoas is under a state of constant contraction. Imagine how a tightened psoas will affect the birth process!

Impact of a Shortened Psoas

The length of the psoas determines whether the pelvis is free to move or not. It becomes shortened from prolonged sitting, excessive running/ walking, sleeping in the foetal position and even stress, as noted above. A shortened psoas muscles affects posture in the following ways:

1. The hips thrust forward, creating rotation of the pelvis and an internal rotation of the affected leg. The opposite leg will rotate externally to counter-balance the asymmetry. To the body, the affected leg is now longer, and every time the person steps, it drives the leg up into the hip socket, creating further imbalance, leading to a functional leg length discrepancy;
2. The pelvis and thigh draw closer, thus limiting space and movement in the hip socket. In essence, the femoral head is locked into the socket and instead of rotation occurring at the hip joint, it produces a torque at the knee and at L4-L5;
3. Spinal segments compress, creating a lordotic posture of the low back and pelvis. The network of lumbar nerves and blood vessels passes through and around the psoas, so tightness here will impede the flow of blood and nerves impulses to the pelvic organs and legs, potentially affecting sexual and elimination functions, and creating numbness and tingling in the legs and feet;
4. It is responsible for menstrual cramps as it puts added pressure in the reproductive organs;
5. It creates a thrusting forward of the ribcage and encourages chest breathing, which limits the amount of oxygen taken in and encourages over usage of the neck muscles. The trunk shortens and the space for the internal organs is decreased, which affects food absorption and elimination, contributing to constipation.

Disclaimer

The article on birth induction is purely for informational purposes and is not intended as a substitute for advice from a physician or other health care professional.

No information in this paper on birth induction is intended for the diagnosis or treatment of any health problem, for health assessment, for prescription of any medication, or for any other health treatment. Consult with a healthcare professional before starting any diet, exercise or supplementation program, before taking any medication, or if you suspect you might have a serious health problem. You should never stop taking any medication without first consulting your physician.

Further Information, Background Reading and Supporting Articles

www.childbirthconnection.org  
www.bellybelly.com  
www.motherandchildhealth.com  
http://somatics.com/psoas.htm  
http://www.birthsource.com  
www.acupunctureproducts.com/acupuncture_meridians.html  
www.childbirthconnection.org/article.asp?ck=10184