Normal Labor and Delivery Physiological Adaptations Presented by Ann Hearn

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

Essential Factors in Labor Passenger Powers Passageway Psychological

THE PASSAGEWAY

THE PELVIS ä Determine if the pelvic cavity is of adequate size to allow for the passage of the full term infant Optimum shaped pelvis is Gynecoid

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

THE PASSENGER And PPRESENTATION

Fetal Head 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 ä Relationship of the long axis of the fetus to the long axis of the mother. Longitudinal Lie Transverse Lie

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

Fetal Presentation ä That portion of the fetus that enters the Pelvis first and covers the internal os. ä Three Types: ä Cephalic ä Vertex, Face, Brow ä Breech ä Shoulder

ä Cephalic = Occiput, posterior fontanel ä Breech = Sacrum ä Face = Mentum Reference Points

Attitude Relationship of fetal body parts to each other Optimum attitude is flexion or ovoid

POSITION

ä Relationship of the Fetal Presenting Part to the Maternal Pelvis ä Steps: 1. Determine the Presenting Part 2. Divide the mothers pelvis into 4 imaginary quadrants A P 12 L R

ENGAGEMENT ä Descent of the fetal presenting part in relation to the ischial spines of the maternal pelvis = 0 station.

Engagement - largest diameter of presenting part has passed through the pelvic inlet - Assessed during vaginal exam Ballotable Engaged

Station Station - degree that the presenting part has descended into the pelvis in Relationship to ischial spines Goal Move from – to + stations

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

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

THE POWERS THE POWERS

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

THE PSYCHOLOGICAL THE PSYCHOLOGICAL

FEAR TENSION PAIN BREAK THE CYCLE !

Techniques for Assessment ä Abdominal Palpation / Leopold’s Maneuver ä Standing on the Right side, face the woman and palpate with the palms of the hands. ä Step 1 - Start at upper fundus and palpate for the head or buttocks ä Step 2 - Go down each side and locate back ä Step 3 - Gently grasp lower portion of uterus and feel for the head or buttock ä Step 4 - Turn and face the woman feet, using both hands palpate lower abd. for cephalic prominence or brow.

Ausculation ä Assess for the area of greatest intensity of the FHR. ä Usually best heard at the fetal back

True or False ? ä If the fetal heart tones (FHT’s) are heard loudest (PMI) in the patient’s upper right quadrant of her abdomen, the fetus would be assessed for a breech presentation. A. True B. False

Vaginal Examination ä Presentation – presenting part (head/buttock) ä Position – fetal head (OA, OP etc.) ä Condition of Membranes – ruptured or intact ä Dilation - enlargement & widening of os (cm) ä Effacement – thinning of the cervix (%)

Vaginal Examination ä Station - degree that the presenting part has descended into the pelvis. Relationship to ischial spines (-, 0, +) ä Engagement - largest diameter of presenting part has passed through the pelvic inlet

Station Station - degree that the presenting part has descended into the pelvis in Relationship to ischial spines Goal Move from – to + stations

Critical Thinking ä 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 ! ä When the cervical os widens or opens it is said to________. ä The level of the ________ _________ (bony structure) is station zero. ä The most common type of pelvis for a woman ____________. ä When the cervix shortens and thins is _______________. ä For delivery to occur, the fetus must accommodate to this rigid passageway______________.

CAUSES OF LABOR Increase in Estrogen Decrease in Progesterone Degeneration of Placenta Over-distention of Uterus High levels of Prostaglandins

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

FORCES OF LABOR ä Contraction - exhibits a wavelike pattern that begins slowly climbing (increment) to a peak (acme), and decreases (decrement) Increment acme Decrement

FORCES OF LABOR Increment acm e Decrement Duration 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 Interval - Resting time between contractions for placental perfusion

Uterine Contraction - review

Fill in the blank ! ä Length of a uterine contraction__________. ä Strength of a uterine contraction is ___________. ä The time from the beginning of one contraction to the beginning of the next contraction is _______. ä The time that allows for placental perfusion is __. ä The peak of a contraction is also known as ____. ä When the biparietal diameter of the head passes through the pelvic inlet it is said to be ________.

Assessment of Contraction ä 1. Subjective symptoms by woman ä 2. Palpation and timing by the nurse ä 3. Use of Electronic Fetal Monitor (EFM)

Duration of Labor ä Resistance of the Cervix ä Presentation and position of the fetus, ä The woman’s pelvis ä Preparation and relaxation of the mother ä Primigravida - up to 22 hrs; average 12 1/2 hrs ä Multigravida hrs; average 10 hrs.

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 FALSE LABOR PAIN (Braxton Hicks) SHOW Rupture of Membranes (ROM) BACKACHE DIARRHEA SUDDEN INCREASE IN ENERGY

True vs. False Labor ä TRUE LABOR ä Contractions are: * Regular * Increase in intensity and duration with walking * Felt in lower back, radiating to lower portion of abdomen ä Bloody show ä Dilation and effacement ä Fetus usually engaged ä FALSE LABOR ä Contractions are: ä * I rregular * No change or decrease with walking * Contractions felt in abdomen above umbilicus Braxton Hicks ä No change in cervix ä Fetus is ballotable

Phases and Stages of Labor  Stage 1: cm.  Phase 1 - Latent - dilate cm.  Phase 2 - Active - dilate cm.  Phase 3 - Transition - dilate 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

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

Mechanisms of Labor/ Cardinal Movements DescentFlexionInternal RotationExtensionExternal Rotation Expulsion

Signs of Stage Three of Labor Globular Shape of Uterus Fundus Rise in Abdomen Sudden Gush of Blood Protrusion of Umbilical cord

 The End Return to Module