Giving Birth Chapter 17

LABOR The Process by which the Products of Conception are expelled from the body

Physiologic Effects Of the Birth Process

Maternal Response

Characteristics of Contractions Contraction-exhibits a wavelike pattern that begins slowly climbing (increment) to a peak, and decreases (decrement) peak Increment Decrement Duration Interval Frequency Duration- from beginning of one contraction to the end of the same contraction Frequency- from beginning of one contraction to the beginning of another contraction Interval - Resting time between contractions for placental perfusion

Opposing Features of Uterine Activity Upper 2/3 of uterus contracts actively Lower third and cervix are passive These lead to downward progression of fetus with each contraction

Cervical Changes Effacement- thinning of the cervix (%) Dilation – enlargement and widening of the os (cm)

Cardiovascular System Changes During each contraction, blood flow to the placenta gradually decreases, causing an increase in the woman’s blood volume causing her B/P to increase and slowing of her pulse. Because these changes occur during a contraction, it is best to assess vital signs between contractions.

What are acceptable positions for the woman to assume while in labor?

Respiratory System Changes During labor a woman is likely to hyperventilate causing: Tingling in hands and feet Numbness Dizziness Have the woman slow her breathing or breath into a paper bag.

Gastrointestinal System Changes Most woman are limited to clear liquids or NPO during the labor process. Gastric motility and digestion of food is reduced. Decrease risk of aspiration Why?

Urinary System Changes Reduce sensations of needing to void Intense contractions Anesthesia Unaware of having a Full bladder Inhibit fetal descent

Hematopoietic System Most woman lose ~ 500ml blood during a vaginal delivery and ~1000ml during a cesarean birth. Clotting factors are elevated and Fibrinolyis is decreased to promote coagulation at the placental site

Components of the Birth Process

Powers

Uterine Contractions Maternal Pushing Efforts Involuntary Uterine Contractions or Primary Powers Muscular contractions which lead to dilation and effacement in the First Stage of Labor Voluntary Uterine Contractions or Secondary Pushing Powers Abdominal muscles assist in the Second Stage with pushing. Increase intra-abdominal pressure to aid in expulsive forces

Fill in the Blank Length of a uterine contraction__________. Strength of a uterine contraction is ___________. The time from the beginning of one contraction to the beginning of the next contraction is _______. The time that allows for placental perfusion is __. The peak of a contraction is also known as ____.

The Birth PASSAGE

THE PELVIS False Pelvis True Pelvis Represents Supports the weight of the uterus Shallow basin above the inlet or brim True Pelvis Represents the bony limits of the birth canal

True Pelvis vs. False Pelvis Inlet Inlet - upper margin of pubic bone to upper margin of sacrum Outlet Outlet - Lower pubic bone to tip of coccyx. This area is the smallest portion that the baby must travel through.

Which has the greatest impact on labor?

The Passenger

Fetal Head Because of its size and rigidity, the Fetal Head has a major impact on delivery. The bones are not firmly united. There are sutures between the bones that allow them to overlap or MOLD to the birth canal. Head also can rotate, flex, and extend Compare the bones, suture lines and fontanels of the fetal head. What do the bones of the fetal head do to accommodate the birth canal?

Fetal Lie Relationship of the long axis of the fetus to the long axis of the mother. Longitudinal Lie Transverse Lie Define the term "fetal lie". Explain the difference between transverse lie and longitudinal lie. Which is the most favorable for a vaginal delivery?  

Attitude Relationship of fetal body parts to Optimum each other attitude is ovoid The head is flexed forward, with the chin almost resting on the chest. The arms and legs are flexed.

True or False? The optimum lie of the fetus is the longitudinal lie. A. True B. False

Fetal Presentation That portion of the fetus that enters the Pelvis first and covers the internal os. Three Types: Cephalic Vertex, Face, Brow Breech Shoulder Define the term “fetal presentation” and explain difference between presentations. Cephalic Presentation The head is entering the pelvis first.

Reference Points Cephalic = Occiput, posterior fontanel Breech = Sacrum Face = Mentum What reference point would the nurse use when assessing cephalic presentation? A breech presentation? A face presentation? What reference point would the nurse use when assessing breech presentation?

POSITION Relationship of the Fetal Presenting Part to the Maternal Pelvis Steps: 1. Determine the Presenting Part 2. Divide the mothers pelvis into 4 imaginary quadrants What is fetal position? What are the steps in assessing position? A 12 R L 9 3 6 P

The Psyche

BREAK THE CYCLE ! FEAR TENSION PAIN 18. How can stress and anxiety interfere with the process of labor? 19. What are nursing interventions to assist clients in decreasing anxiety? PAIN

Normal Labor

Theories of Onset Decrease in Progesterone High levels of Prostagladins Stretching, pressure or irritation of the uterus and cervix 20. What are the possible causes of labor onset?

Premonitory Signs of Labor The impending signs that take place the last several weeks of pregnancy or even the last several days What are the premonitory signs of labor?

Premonitory Signs of Labor LIGHTENING Braxton-Hicks Contractions Cervical changes SHOW ROM BACKACHE SUDDEN INCREASE IN ENERGY Weight loss

True vs. False Labor FALSE LABOR TRUE LABOR Contractions are irregular Often stop with walking Contractions felt in abdomen above umbilicus (abdominal pains) No change in cervix Fetus is ballotable TRUE LABOR Contractions are: * Regular *Increase in intensity and duration with walking *Felt in lower back, radiating to lower portion of abdomen Bloody show Dilation and effacement Fetus usually engaged 23. What assessment findings differentiate true labor from false labor?

Mechanisms of Labor/ Cardinal Movements Engagement / Descent Flexion Internal Rotation Extension External Rotation 25. Explain the positional changes /cardinal movements of stage 2 and why they occur in this order? Expulsion

Engagement Engagement -largest diameter of presenting part has passed through the pelvic inlet Assessed during vaginal exam Ballotable 8. What is engagement? How is it determined? Engaged

Station Station- degree that the presenting part has descended into the pelvis in Relationship to ischial spines Goal Move from – to + stations 9. What is station? How is station determined and measured? Does the station need to be a + or – for delivery?  

Phases and Stages of Labor Stage 1 – From 0 cm. dilated to 10 cm. Stage 2 - From complete dilation and effacement to delivery of the baby Stage 3 - From delivery of baby to the delivery of the placenta Stage 4 - the first hour after delivery

Phases of First Stage of Labor Latent Phase – is from 0 to 3 cm. dilated Active Phase – is from 4cm. to 7 cm. Transition Phase – is from 8 cm. to 10 cm. 24. What are the three phases of the first stage of labor and characteristics of each? (p. 407-409)

Signs of Second Stage of Labor Complete dilatation of cervix Urge to bear down Perineum begins to bulge, flatten and move anteriorly Increase in bloody show Rectal pressure Labia begins to part with each contraction

Signs of Stage Three of Labor Globular Shape of Uterus Fundus Rise in Abdomen Sudden Gush of Blood Protrusion of Umbilical cord What are the signs in the third stage that indicate that the placenta is ready for delivery?

Test Yourself ! What is the reference point of a cephalic presentation when the head is fully flexed? A. occiput B. mentum C. frontal d. sagittal

Test Yourself Overlapping of the fetal skull to facilitate its passage through the bony pelvis is ___________. Relationship of fetal body parts to each other is_____________. Head first presentation is_________________. Relationship of the fetal spine to the maternal spine is ________________. Term that refers to the part of the fetus that enters the pelvic inlet first is _____________.

Critical Thinking If the fetal head did not descend through the pelvis and stayed at the same station for a prolonged period of time, what do you think would be the treatment of choice?

Try this ! When the cervical os widens or opens it is said to________. The level of the ________ _________ is station zero. The most common type of pelvis for a woman ___________. When the cervix shortens and thins is _______________. For delivery to occur, the fetus must accomodate to this rigid passageway______________.

The End