Chapter 16: Labour and Birth Process

1. Passenger (fetus and placenta)

2. Passageway (birth canal, bony pelvis)

3. Powers (contractions

4. Position of mother

5. Psychological response

Five factors affect the process of labour (5 P’s)

fetal lie

How fetal spinal column lines up with maternal spinal column

Longitudinal

Normal fetal lie (vertex presentation OR breach)

Transverse

Fetal lie with shoulder presentation

Flexed

Normal fetal attitude

Straight up and down (head not flexed)

“military” fetal attitude:

Face/brow

fetal attitude where head is extended backward

Fetal position

where presenting part of fetus is in relation to maternal pelvis

Occiput anterior

Occiput of fetal head is s in anterior portion of mother’s pelvis:

Sunny side up

Presentation when fetus occiput is pressing on sacrum.

Larger diameter trying to fit. Diameter is smaller in occiput anterior

Why is occiput posterior less optimal for delivery?

Occiput anterior

Optimal fetal position for birth

Engagement

Refers to the fetal head coming into the true pelvis and lining up with the ischial spines.

Station

Measurement of hhow deep fetus is into bony pelvis. Measureed in centimetres in relation to the ischial spines (anything below ischial spines is a positive number)

Station 0: fetal presenting part comes in line with ischial spines

What station is engagement?

Suture lines

Allows the fetal skull to fit through the bones of the bony pelvis

Anterior fontanelle

Largest fetal fontanelle

a year and a half to two years

How long does it take for fontanelles to close?

They can palpate the anterior or posterior fontanelle

HOw do fontanelles allow HCP to determine presenting part?

Occiput

Bone at the back of the head

Fetal head

Most common presentation (first part coming through pelvis)

Frank breach

Breach where legs are flexed right to chest

Footlong breach

Presenting part is leg, legs are coming first

Complete breach

Breach where legs and buttocks are coming at the same time

Pelvis inlet

Upper border of the true pelvis. posteriorly to anteriorly

Bony pelvis

formed by the fusion of the ilium, ischium, pubis, and sacral bones

True pelvis

The part of the pelvis involved in birth

Pelvis outlet

The lower border of the true pelvis. Extends from sacrum to pubic symphysis and allows hetal head to change direction

Introitus

External opening to the vagina

The pevlic floor is full of muscles. On the first baby, it takes a longer time for the muscles to stretch. On the second baby, the tissues have already stretched, and they don’t have to work as hard to stretch,

Why might having a second baby be easier than the first (related to pelvic floor muscles)

1. Gynecoid

2. Android

3. Anthropoid

4. Platypelloid

Four basic types of pelves are classified as follows:

Gynecoid

Classic female pelvis type, most contusive to vaginal birth, more likely to have vaginal spontaneous OA position births

Android

Pelvis resembling male pelvis. It tends to be more narrow. Has c-section and vaginal births, more likely to need instrumental help (forceps, etc.)

Anthropoid

Pelvis more like an ape’s, tends to be more oval. Still able to deliver vaginally, but can be more OP.

Platypelloid

Flatter pelvis shape. Still contusive to spontaneous vaginal birth

In the fundus, then work their way down the uterus

Contractions begin where?

Dilate and efface the cervix

Contractions work to what?

Pelvis floor

Muscular layer that separates the pelvic cavity above the perineal space below. Helps the fetus rotate anteriorly as it passes through the birth canal.

Primary powers

Spontaneous contractions are called:

Effacement

Thinning of the cervix, measured in percentage

Dilation

Opening of the cervix (measured in cm)

-1. If you can’t, that would be station 0 or below

During internal exam, if you can get finger between fetal head and ischial spine, this means they are at station what? what if you can’t?

1. fetus

2. placenta

3. amniotic fluid

Goal of labour is to get what out? [3]

Latent phase of the first stage

In what phase do contractions start?

Includes zero-10cm dilated and fully effaced. When labour first starts.

First stage of labour:

1. latent phase

2. active phase

Two phases within first stage of labour:

Latent phase

Phase of labour when cervix is dilated 0-3cm

Active phase

Phase of labour when cervix is dilated 4-10cm

ferguson reflex

When presenting part of fetus reaches the perineal floor, stretching of the cervix occurs, causing oxytocin to trigger the urge to bear down

Do an internal exam to asses cervix, see if it has all moved away yet

First thing to do when mother feels urge to bear down

secondary powers

The bearing down efforts when mother feels an involuntary urge to push

Whatever she wants. Frequet changes in position relieve fatigue, increase comfort, and improve circulation. encourage her to find a position that works for her.

what is the best position for a labouring woman?

Walking, sitting, kneeling, and squatting allow gravity to promote the descent of the fetus. Improves blood flow (increased CO)Contractions are stronger and more efficient this way, resultin in shorter labour

Advantages of upright labouring position:

Labour

The process of moving the fetus, placenta, and membranes out of the uterus and thorugh the birth canal

2 to 4 weeks before term, and happens gradually.

IN first pregnancies, when does fetus’s presenting part descend into the true pelvis? (

Lightening or “dropping”

When uterus sinks downward and forward and presenting part (usually fetal head( descends into the true pelvis

Braxton hicks

Strong, frequent, but irregular uterine contractions

Bloody show

vaginal mucous can become more profuse in response to extreme congestion of vaginal mucous membranes. Brownish or blood-tinged cervical mucous may pass preceeding birth

Caused by water loss resultin from electrolyte shift that is produced from changes in estrogen and progesterone levels

Why might women lose a little bit of weight preceding birth (0.5-1.5kg)

Within 24 hours

If membranes rupture spontaneously, when will she typically give birth?

Due to relaxation of pelvic joints

Why might mothers feel persistent low back pain preceding labour?

Nesting

Surge of energy preceding birth that mothers often use to clean the house and put everything in order

• Lightening

• Return of urinary frequency

• Backache

• Stronger Braxton Hicks contractions

• Weight loss of 0.5 to 1.5 kg

• Surge of energy (also called nesting)

• Flulike symptoms

• Increased vaginal discharge; bloody show

• Cervical ripening

• Possible rupture of membranes

Signs preceding labour [10]

Amnio stick test

Looks like a q-tip but changes colour. If it turns blue, it is amniotic fluid and not urine.

A fern pattern

How will amniotic fluid look on a slide under a microscope?

1. changes in maternal uterus, cervix

2. pituitary gland

3. hormones by fetal hypothalamus, pituitary, and adrenal cortex

4. Progressive uterine distension

5. increasing intrauterine pressure

6. Increased estrogen, oxytocin, and prostaglandins

7. decreased progesterone

What changes are involved in the onset of labour? [7]

1. regular proression of uterine contractions

2. effaceent and dilation of the cervix

3. reular progression of the presenting part

Course of normal labour consists of: [3]

much longer than second and third combined.

Relative length of the first stage of labour

18 hours or longer

How long can full dilation take in first time pregnancies?

second stage of labour

Stage of labour that lasts from the time the cervix is fully dilated to the birth of the fetus.

1. latent phase (passive fetal descent, rotating anteriorly)

2. Active pushing phase

Two phases of the second stage of labour

Passive phase of second stage

When is epidural given?

Third stage of labour:

stage that lasts from the birth of the fetus until the placenta is delivered. may be as short as 3-5 minutes, up to 1 hour.

Third or forth stron contraction after baby is born.

When does placenta separate normally?

Fourth stage of labour

Stage of labour that begins with the delivery of the placenta and includes the first two hours after birth. The period f imediate recovery, parent-child bonding. Attachment begins and breastfeeding is initiated.

1 hour

How long is optimal for uninterrupted skin to skin after baby is born?

Q15 minute checks for hemorrhage, vitals, fundus, flow, perinium (sutures)

How often are checks on mom and baby during fourth stage of labour?

engagement

When presenting part is a the level of the ischial spine. Statio 0.

Asynclitism

If neck is bent slightly to the side in engagement. Impacts how well they are able to descend.

Descent

Descending through the pelvis until the pelvic floor.

Flexion

Head flexes in on the chest because the smallest diameter of the fetal head will present at the outlet.

suboccipitobregmatic

smallest diameter of the fetal head

Extension

Delivery of occiput first, then the face, and finally the chin. Happens in one contraction

external rotation

Wait for next contraction after extension to allow this of the fetal head

Restitution

After external rotation of the head, the shoulders line up with the head internally. Anterior shoulder, posterior shoulder, and baby is out

Tearing

What can happen if we do not allow time for external rotation and restitution?

Occiput transverse

When baby is facing side on

Spinning babies

A series of maneuvers that the nurse will support the woman to get into in order to get baby into occiput anterior

When muscles contract, reduces blood flow to fetus. Normal healthy fetuses can withstand forces of labour

Effect of labour on blood flow to fetus:

Intermittent auscultation

Way of monitoring fetal heart by fetoscope or doppler. recommended for women who are healthy at term

Electronic fetal monitor (EFM)

Computerized machine that picks up fetal HR. Also has a toco (measures contractions) that sits at the fundus

High-risk pregnancies. Should not be used on healthy women.

EFM should only be used for whom?

Crownin

Widest part of the fetal head coing through the vaginal opening

Support perineum with hand and STOP pushing. reduces tearing.

It important to do what when baby is crowning?

Help her cope and not feel stretching as much. Also provides amnesia, so they don’t remember how painful it was.

What do endorphins do when baby is crowning?