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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.
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Giving Birth Chapter 17
LABOR The Process by which the Products of Conception are expelled from the body
Physiologic Effects Of the Birth Process
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 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 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
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 • 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.
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
Fetal Lie • Relationship of the long axis of the fetus to the long axis of the mother. Longitudinal Lie Transverse Lie
Attitude Relationship of fetal body parts to each other Optimum attitude is ovoid The headis 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 Cephalic Presentation The head is entering the pelvis first.
Reference Points • Cephalic = Occiput, posterior fontanel • Breech = Sacrum • Face = Mentum
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 A 12 R L 9 3 6 P
BREAK THE CYCLE ! FEAR TENSION PAIN
Premonitory Signs of Labor The impending signs that take place the last several weeks of pregnancy or even the last several days
Premonitory Signs of Labor • LIGHTENING • Braxton-Hicks Contractions • Cervical changes • SHOW • ROM • BACKACHE • SUDDEN INCREASE IN ENERGY • Weight loss
True vs. False Labor 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 FALSE LABOR • Contractions are irregular • Often stop with walking • Contractions felt in abdomen above umbilicus (abdominal pains) • No change in cervix • Fetus is ballotable
Mechanisms of Labor/ Cardinal Movements
Engagement Ballotable • Engagement -largest diameter of presenting part has passed through the pelvic inlet • Assessed during vaginal exam • Engaged
Station • Station- degree that the presenting part has descended into the pelvis in Relationship to ischial spines Goal • Move from – to + stations
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.
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
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______________.