- Consist of 4 layers of smooth muscle cells

Stratum submucosum – thin layer,prediominantly longitudinal bundle

Stratum vasculare – outside stratum submucosum many blood blood vessels gives spongy appearance,longitudinal bundles

Stratum supravasculare – mainly circular bundles,some longitudinal bundles

Stratum subserosum – outermost,thin layer of longitudinally oriented fiber bundles

Each myometrial cell has proteins

plasma membrane

involved in the process of ion transport and compose the

receptor sites for endogenous and

exogenous substances.

The cell membrane also

contains gap junctions that

allow communication from cell to cell

and provide synchronization

during labor.

Besides containing the normal cellular

organelles, the smooth muscle cells of the

myometrium contain myofilaments consist of actin and myosin. The

interaction of these two proteins with calcium

and adenosine triphosphate (ATP) is the pathway that causes the smooth muscle cell to contract.

The transmembrane junction consists

of two protein hemichannels

connexons.

Each of them composed of six connexin subunit

protein.

Synchonization of myometrium smooth muscle

cells cause powerful waves of myometrial

contraction

During labor

- During the process of labor, The myometrium contracts by a positive feedback effect on the "Ferguson reflex"),

- Strong contraction of the myometrium are influenced by the action of the hormone oxytocin secreted by the posterior pituitary and hormone prostaglandins from placenta.

- These contractions expel the fetus from the uterus into vagina and also constrict the blood supply to the placenta.

-After delivery, the myometrium contracts to expel the placenta and reduce blood loss; where the crisscrossing fibres of middle layer compress the blood vessels.

-Contractions of the uterus after the cervix has been stimulated. -During labor, the urge to push is created by the Ferguson reflex. -The urge to push is caused when the baby is pressed onto the Ferguson Plexus of nerves.

‘’HARD WORK’’

FULLY NORMAL NATURAL PROCESS

THROUGH NORMAL BIRTH CANAL

DUE TO NATIVE EXPULSION FORCE

Natural resistance force of pelvic floor and

uterine contraction

‘’WITH HELP’’

THE PROCESS OF GIVING BIRTH WHICH REQUIRES MEDICAL HELPS

For example :

OPERATIONAL DELIVERY (CAESAREAN -Section)

1. Uterine distention : - Stretching effect of the myometrium

by the growing fetus and liquor amnii on the uterus.

1. Feto-placental contribution : - CRH Pituitary, ACTH Fetal adrenal gland,glucocorticoid accelerated production of estrogen and prostaglandins from placenta reduce progesterone production

2. Increase oestrogen (increase excitability of myometrium membranes and increase synthesis of Prostagladin)

3. Increase Prostaglandin (maintain labor) 4. Decrease Progestrone (increase contractility)

REGULAR CONTRACTION - Contraction occur when the uterine muscles tighten and

relax. - When true labor begins, the pituitary gland releases

oxytocin. Oxytocin is a hormone that stimulates contractions.

- True labor contractions are different from Braxton Hicks because they make labor progress. - Contractions usually start in the back and move around

to the front. The contractions can be felt as a cramping or tightening sensation.

false labour, It should be infrequent, irregular, and involve only mild cramping.

PASSING OF THE MUCUS PLUG -The cervix is "plugged" with a thick piece of mucous that helps protect fetus during pregnancy by blocking the entrance to the uterus. - As cervix effaces and dilates, the mucus plug will be released. - The mucus is discharged into the vagina and may be clear, pink, or slightly bloody. Time to labor? -Few days to hours.

BACK LABOR - "Back labor" refers to the pain and discomfort that

laboring women experience in their lower back

- A frequent cause of back labor is the position of the baby. Positions such as occiput posterior (when baby is facing the mother’s abdomen) can cause pressure from the baby’s head to be applied to the mother’s sacrum (the tailbone).

- The result can be intense discomfort during labor.

. .

Starts with Regular uterine contractions and ends with beginning of cervical dilatation and effacement.

-Increase velocity of cervical dilatation in short duration (4 hourts) from 3cm to 7cm - Uterine contractions become intensively increase – more frequent, longer, and stronger.

- Decrease velocity of cervix dilatation from 7cm to maximum dilation (10cm) and to full effacement : maternal os - It occurs because the head descend and is in contact with the cervix.It gives force to cervix to dilate more (because presenting part of fetus 9.5cm and cervical dilatation only 7cm) - Cause cervix to dilate until full dilatation

- During active labor,the uterine divisions that are initiated phase 2 of parturition (Preparation of Labor) become increasely evident.

- During contraction : - upper segment becomes firm - lower segment becomes softer,distended and more passive - Physiological retraction ring is formed between the upper and lower segment of the uterus.

- Functions of lower and upper uterine segment during 1st stage of labor : the upper segment

contract,retracts and expels the fetus.In response to these contractions,the softened lower uterine segment and cervix dilate and thereby form a greatly expanded,thinned out.

- Fetus can pass through lower segment.

- The upper uterine segment does not relax to its original lentgh after contraction,it becomes relatively fixed at shorter length (retraction) : to maintain and gain expulsive force of fetus

- Cervical effacement occurs because of increased myometrial activity during uterine preparation for labor just after cervix is ripened.

- The cervix gradually softens, shortens and becomes thinner. It is called cervical effacement.

- The muscular fibres at about the level of the internal cervical os are pulled upward,or ‘taken up’,into the lower uterine segment.The condition of the external os remains unchanged.

- The presenting part, applied to the cervix and forming lower uterine segment

- Because the lower uterine segment and cervix have lesser resistance during a

contraction,the uterine contraction cause pressure on the membranes and hydrostatic action of amniotic sac in turn dilates the cervical canal.

It is called cervical dilatation.

- Start when cervical dilatation is complete and end with the expulsion of the fetus

head of fetus descend passes through the muscular birth canal

PUSH (voluntary movement) occurs. the head of fetus pressed on the muscle of pelvis causing increase sensitivity on the stretch receptor on pelvic muscle and cause mother to have the urge to push the fetus out from the vagina

As the fetal head continue descend, the vaginal opens and the fetal scalp appears.

At first, it appears slit-like then becomes oval and then circular. This is called crowning.

As she continue pushes, using her abdominal muscles to aid the involuntary uterine contractions, the fetus is pushed out of the birth canal.

- Occurs immediately after delivery of the fetus.Happen 30 minutes to prevent excessive bleeding

There are 4 classes of blood loss:

250-300 ml = average blood loss

> 500 ml = high blood loss

1 L = mild bleeding

> 1.5 L = severe bleeding

- Two separate phases are involved: • placental separation the placenta descent to the lower segment and finally expulsed with the membrane • placental expulsion occurs by being forced out by the effective contraction and retraction of the uterus with the voluntary contraction of abdominal muscles.

-Occurs from the moment of the birth until 6th weeks (If prolongation occur,it is called delay period) -Events occur during this period : 1. There is sustained uterine contraction to prevent postpartum

hemorrhage 2. Lactogenesis (breastfeeding) 3. Uterine involution and cervical repair ( to enable the reproductive

organs to return to non-preggy state) 4. Resumption of ovulation 3 phases of postpartum period :

-The initial or acute period involves the first 6–12 hours postpartum. This is a time of rapid

change to occurs such as postpartum hemorrhage, uterine inversion, amniotic fluid embolism, and eclampsia.

-The second phase (subacute postpartum period) lasts 2–6 weeks. the changes are less rapid than in the acute postpartum phase and the patient is generally capable of self-identifying problems.

The third phase (delayed postpartum period)

can last up to 6 months. Changes during this phase are extremely gradual, and pathology is rare.

1. IDENTIFICATION OF LABOR

To differentiate True and False Labor

Characteristics True Labour False Labour

Contraction Regular and gradually short interval

Irregular and unchanged interval

Cervical Dilatation Yes No

Discomfort Back and abdomen Lower abdomen

2. CERVICAL EXAMINATION

- Cervical effacement - Cervical dilation - level of station (distance between fetal part in birth canal and inshial spine)

The functions of a vaginal examination are to: • Identify the fetal presentation and position 4 movements of vaginal examination: 1) Insert 2 fingers into vagina 2) Fingers directed posteriorly and then swept forward over the fetal head toward maternal

symphysis. During the movement, the fingers should cross the saggital suture 3)The position of 2 fontanels are ascertained.the fingers are passed to most anterior

extension of saggital suture , and fontanel there is examined and identified. Then with a sweeping motion the fingers pass along the suture to other end of head until the other fontanel is felt and differentiated.

4) The station, or extent to which the presenting part has descended into the pelvis, can

also be established at this time.

3. VAGINAL EXAMINATION

4. DETECTION OF RUPTURED MEMBRANE - Diagnosed when amniotic fluid is seen - pH determination of vagina fluid - Indicator used : Nitrazine

Vaginal fluid Amniotic fluid

pH 4.5 – 5.5 7.0 – 7.5

Monitoring fetal well-being during labor -Monitoring the fetal heart rate by using Cardiotocography (CTG) at least every 30 minutes in first stage and then every 15 minutes during second stage.

Intravenous Fluids -An intravenous infusion system is advantageous during the immediate puerperium to administer oxytocin prophylactically and at times therapeutically when uterine atony persists. -Moreover, with longer labors, the administration of glucose, sodium, and water to the otherwise fasting woman at the rate of 60 to 120 mL/hr prevents dehydration and acidosis.

Subsequent Vaginal Examination

PARTOGRAM

a graphical representation that

record the observation and information

from the monitoring of the mother and

fetus.

Consists :

Maternal status

Fetal heart rate

Dilatation & descent

Uterine contractions

analgesia -The pain of childbirth is likely to be the most severe pain that a woman experiences during her lifetime.

-Analgesic that we use : Meperidine, 25-50 mg IV every 1-2 hours or 50-100 mg IM every 2-4 hours Fentanyl, 50-100 mcg IV every hour Nalbuphine, 10 mg IV or IM every 3 hours Butorphanol, 1-2 mg IV or IM every 4 hours Morphine, 2-5 mg IV or 10 mg IM every 4 hours As an alternative, regional anesthesia may be given. Anesthesia options include the following: Epidural (common) Spinal Combined spinal-epidural

ACTIVE MANAGEMENT

Active management of labour (AML) is a structured protocol for the management of all parturients in labour with the aim of reducing prolonged labour. Its aim was to keep labour to fewer than 12 hours and operative delivery rates to a minimum. Two of its components are performed : -Amniotomy -Oxytocin When dilation is not increased by 1cm per hour,amniotomy is performed.After 2 hours,high dose oxytocin infused if still not dilated.

ARM, (Artificial rupture of the membranes) AMNIOTOMY -breaking the membranes that surround the baby and releasing the amniotic fluid before it breaks naturally itself. -This is performed with the use of a long sharp hook similar to a crochet hook that is inserted through vagina and cervix and used to make a small nick in the membranes allowing the waters to escape. Patient will be required to lay on her back with her legs open while this procedure is preformed. -ARM’s are used to either help start labour before it is ready to started itself, or speed up a labour that is not moving fast enough for either the care provider or the mother.

• Once the cervix is fully dilated and the woman is in the expulsive phase of the second stage, encourage the woman to assume the position she prefers and encourage her to push

• Most widely used is dorsal lithotomy position.

PREPARATION FOR DELIVERY Positions that a woman may

adopt during childbirth

POSITIONING FOR DELIVERY

-Need 6 swab balls

-Clean sequentially as shown by the numbers

-Clean according to the direction shown by the

Arrows

-Delivery must be sterile and antiseptic procedure

PERINEUM CLEANING

CREATE A STERILE FIELD AROUND THE VAGINAL OPENING

• Note:

– Not a routine procedure and are considered preventing tear

– Do not decrease • perineal damage • future vaginal prolapse • urinary incontinence

– Associated with

• an increase of 3rd & 4th degree tears • subsequent anal sphincter muscle

dysfunction.

• Considered only in:

– complicated vaginal delivery • breech • shoulder dystocia • forceps • vacuum

– scarring from female genital mutilation or

poorly healed third or fourth degree tears

– fetal distress.

EPISIOTOMY

ASSISTING WITH DELIVERY

• Ritgen Maneuver is performed • As crowning occurs, place a hand on the top of the

baby’s head and apply light pressure • Instruct the mother to focus on her breathing. Have her

“pant like a dog” to help her stop pushing and prevent a forceful birth.

DELIVERY OF THE HEAD

• Ask the woman to pant or give only small pushes with contractions as the baby’s head delivers

• To control birth of the head, place the fingers of one hand against the baby’s head to keep it flexed (bent)

• Continue to gently support the perineum as the baby’s head delivers

DELIVERY OF THE HEAD

DELIVERING OF THE SHOULDERS

• Once the baby’s head delivers, ask the woman not to push

• Suction the baby’s mouth and nose

Nuchal Cord

If the cord is around the neck, attempt to slip it over the baby’s

head

Feel around the baby’s neck

for the umbilical cord

If the cord is tight around the neck, doubly clamp and cut it before unwinding it from around the neck

SUCTION THE BABY’S MOUTH AND NOSE

• The side of the head are grasped with two hands and gentle traction is applied until anterior shoulder appears

• Upward movement until posterior shoulder is delivered

ASSISTING WITH DELIVERY

Use a clean towel to catch the baby

Check to see if the umbilical cord is looped around the baby’s neck. If so, gently slip it over the head

As the head emerges, the baby will turn to one side (for easier passage of shoulders through birth canal)

BABY DELIVERED

FIRST BODY CONTACT OF MOTHER AND BABY AND CORD CLAMPING

CLAMPING, CUTTING AND TYING OF

UMBILICAL CORD

Expectant management

• Talk to the woman and tell her that you will deliver her placenta

• Wash your hands and put on your sterile gloves

• After having the signs of placental separation, hold the clamp close to the perineum with one hand.

• Deliver the placenta by putting one hand just above the pubic bone.

• Tell the mother that she can strain when there is uterine contraction

4 signs of pacental separation :

-Uterus becomes globular and firm

-Sudden gush of blood -Uterus rise in the

abdomen and placenta pass down into vagina

-Umbilical cord protrudes farther out of vagina

Expectant management

• Gently guide the placenta downward and outward by holding on the cord.

• Be gentle because a hard pull can tear or break the cord and even worst, turn the uterus inside out

• As the uterus stays in place and the cord gets longer , continue to guide gently until the placenta is delivered

• When the bulk of the placenta is out,hold it with your two hands

• Rotate the placenta like twisting a rope until delivered so that the fetal membranes will come out.

Expectant management • Feel the uterus from the abdomen

and massage it to keep it contracted.

• Inject an oxytocin drug intramuscularly to control bleeding.

• The best time to inject oxytocin during

the 3rd stage of labor:

A. After the delivery of the baby

B. After the delivery of the placenta

• Repair episiotomy

• Controlled cord traction

• Massage of uterus

• Majority of Certified Nurse Midwives

• Midwife usually only available for woman who are healthy and with low-risk pregnancies.

• Able to share more on emotions

• Available for home birth

• Cannot perform C-Sections

• Went to medical university followed by 3 years of internship

• Specialized in pregnancy and birth with different complications.

• Normally only provide medical advice

• Usually don’t provide home birth care.

• Able to perform C-Sections.