1. Normal Labor and Delivery
Bridgett Casadaban
July 25, 2007

2. Definitions
Labor – Uterine contractions that result in effacement and dilatation of the cervix.
Braxton-Hicks – Uterine contractions NOT associated with cervical change.
Shorter in duration
Less intense
Over lower abdomen and groin
Resolve with ambulation
Lightening – Descent of the fetal head into the pelvis
Lightening – easier time breathing. Occurs earlier for G0.

3. Definitions Preterm labor – Prior to 37 weeks Term – 37 to 42 weeks
Post term – After 42 weeks
Post dates – After 40 weeks

4. UVA Labor and Delivery
22yo G2P1 at 39 wks comes into L&D complaining of RUC’s q5 minutes x 2 hours. Diana has hooked the patient up to the monitor and brings the patient’s chart to you to further evaluate the patient. What to do next?

5. UVA Labor and Delivery Talk with the patient Confirm ctx history LOF?
Vaginal bleeding?
Feeling baby move?
Desires an epidural?
Distance from home to hospital?
GBS status?
q5 minutes x 2 hours
Yes No No

6. UVA Labor and Delivery Examine patient Rule out rupture Check cervix
Negative pooling, nitrazine, ferning
2/50/-1

7. UVA Labor and Delivery Formulate a plan
You decide to allow the patient to walk around the hospital for 2 hours then return for a cervical check. What steps must you take next before the patient can leave L&D?
*Ultrasound to confirm fetal presentation
*Confirm a reactive/reassuring strip

8. UVA Labor and Delivery
Patient returns in 2 hours with continued, uncomfortable ctx’s q5 minutes. Now what?
Recheck cervix
5/90/0
Now what?

9. UVA Labor and Delivery Admit patient to Labor and Delivery
Complete H&P
*Obtain EFW by Leopold’s
Consents signed for delivery and potential blood transfusion
Orders entered into MIS
Clear diet
IVF’s
T&S/CBC
GBS prophylaxis?
Continuous EFM vs. intermittent
Intermittent = FHTs q 30 min to include a ctx and immediately after
Membranes intact or SROM and well-engaged
Continuous
NRFHTs, SROM and poorly engaged, augmented labor, epidural?

10. UVA Labor and Delivery
In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery:
Stages of labor
Mechanics of labor
Cardinal movements of labor
Delivery

11. Stages of Labor 1st Stage
Interval between onset of labor and full cervical dilatation
2 phases:
Latent – period between onset of labor and point at which a change in slope of rate of cervical dilatation is noted.
Active – Greater rate of cervical dilatation and usually begins around 2-3cm

12. Stages of Labor 2nd stage 3rd stage
Interval between full cervical dilatation and delivery
Duration
Nulliparous – 3 hrs w/ epidural; 2 hrs w/o epidural
Multiparous – 2 hrs w/ epidural; 1 hr w/o epidural
3rd stage
Delivery of the placenta and membranes
Duration – maximum of 30 minutes

13. Normal Labor and Delivery
In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery:
Stages of labor
Mechanics of labor
Cardinal movements of labor
Delivery

14. Mechanics of Labor The Powers Forces generated by uterine musculature
Frequency, amplitude, and duration of ctx’s
Observation, manual palpation, tocodynamometry, intrauterine pressure catheter (IUPC)
Measured in Montevideo units
Average strength of ctx’s (mmHG) x no. of ctx’s in 10 minutes
Adequate MVUs
External monitoring measure the change in shape of the abdominal wall as a fxn of uterine contractions, therefore qualitative rahter than quantitative. Allows accurate correlation of FHT pattern with uteirne activity, does not allow measurement of ctx intensity or basal intrauterine tone.
IUPC - Most precise. Come at a cost—require membrane rupture, risk of uterine perforation, infection

15. Mechanics of Labor Passenger Fetal size Lie Presentation
Abdominal palpation or Ultrasound
Macrosomia (>4500g) associated w/ failure to progress
Lie
Longitudinal axis of fetus relative to longitudinal axis of uterus
Longitudinal*, transverse or oblique
Presentation
Fetal part that directly overlies pelvic inlet
Cephalic, breech, or shoulder
Compound – presence of >1 fetal part overlying the pelvic inlet
Funic – umbilical cord presenting at pelvic inlet
Malpresentation – any presentation that is not cephalic with occiput leading
Fetal size calculations subject to large degree of error
Malpresentaiton – 5% of term labors

16. Mechanics of Labor Passenger (cont) Attitude Position
Position of head with regard to fetal spine (ie: degree of flexion or extension)
Flexion allows smallest diameter of fetal head to present at pelvic inlet
Position
Relationship of a nominated site of presenting part to denominating location on internal pelvis
Example: cephalic presentation
Position – cephalic presentation, nominated site is the occiput. Breech presentation, nominated site is the sacrum
Malposition = any position NOT ROA, OA, or LOA

17. Mechanics of Labor

18. Mechanics of Labor Passenger (cont.) Station Multifetal Pregnancy
Measure of descent of presenting part of the fetus through the birth canal.
Multifetal Pregnancy
Increase probability of abnormal lie and malpresentation in labor
Station – ischial spines mark mid-point (0 station)

19. Mechanics of Labor Passenger (cont.) Leopold’s maneuvers
#1 – Correct dextrorotation of the uterus with the back of one hand and delineate the fundus with the other to determine gestational age and/or appropriate size.
#2 – Run hands down maternal abdomen on either side of fetus to determine fetal lie, identifying small parts and fetal spine
#3 – Firmly grasp upper and lower poles of fetus by placing fingers at uterine fundus and above symphysis to determine presentation and fetal size.
#4 – Move hands in bilaterally from anterior superior iliac crests to determine whether or not the presenting part of the fetus is engaged in maternal pelvis.
Head regarded as unengaged if examiner’s hands are see to converge below fetal head.
#1 - Dextrorotated b/c of sigmoid colon position
#3 -Breech is oftern larger, softer, less well defined

20. Mechanics of Labor
Passenger (cont.)

21. Mechanics of Labor Passage Bony pelvis + soft tissues
X-ray pelvimetry now rarely used, having been replaced by a trial of labor
4 types of the female bony pelvis
Bony pelvis = sacrum, ilium, ischium, and pubis
Soft Tissue = 1st stage of labor  cervix
2nd stage of labor  pelvic floor muscles
Gynecoid – preferred; oval shaped, far-space ischial spines
Anthropoid – exaggerated oval shape to the inelt with alrgest diameter being A-P. More often associated w/ occiput deliveries.
Android – male pattern, heart-shaped, prominent sacral promonitory and ischial spines. Increased risk of CPD.
Platypelloid – Broad, flat, exaggerated oval-shaped inlet

22. Normal Labor and Delivery
In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery:
Stages of labor
Mechanics of labor
Cardinal movements of labor
Delivery

23. Cardinal Movements of Labor
Engagement
Passage of widest diameter of presenting part to level below the plane of the pelvic inlet
0 station
Occurs earlier in nulliparous women (36 wks)
Descent
Downward passage of presenting part through the pelvis.
Flexion
Occurs passively as the head descends due to the shape of the bony pelvis and resistance of pelvic floor soft tissues
Allows smallest diameter of fetal head to pass through the pelvis.

24. Cardinal Movements of Labor
Internal Rotation
Rotation of presenting part from original position (transverse) to anteroposterior position
Extension
Occurs once fetus has descended to the level of the introitus
Base of occiput in contact with inferior margin of symphysis pubis
External Rotation
Return of fetal head to correct anatomic position in relation to the fetal torso
Expulsion
Delivery of rest of fetus
Anterior shoulder delivered first with rotation under the symphysis pubis

25. Cardinal Movements of Labor

26. Normal Labor and Delivery
In order to maximize the patient’s chance at a vaginal delivery it is important to understand the basics of labor and delivery:
Stages of labor
Mechanics of labor
Cardinal movements of labor
Delivery

27. How to effectively deliver a baby
Prepare for the delivery taking into account parity, progression of labor, presentation of fetus, complications of labor
When head crowns and delivery is eminent, protect the perineum + downward pressure to keep head flexed
Ritgen’s maneuver my help if delay in delivery of the fetal head
Sterile towel used to palpate fetal chin through the rectum to apply upward pressure to facilitate extension of fetal head
After delivery of head
Allow for external rotation (restitution).
Reduce nuchal cord
Suction fetal mouth and nares
After clearing fetal airway
Place a hand on each parietal eminence to apply downward traction to deliver anterior shoulder
Followed by upward traction to deliver posterior shoulder
With traction, avoid perineal injury and brachial plexus

28. How to effectively deliver a baby
After complete delivery of infant
Cradle in a single arm below the perineum to allow maximal blood transfer to infant
Delivery of the placenta
3 classic signs of placental separation:
Lengthening of the umbilical cord
Gush of blood from vagina
Change in shape of the uterine fundus to a more globular appearance
Active management of 3rd stage has been shown to reduce total blood loss
Brandt-Andrews Maneuver: abdominal hand secures the uterine fundus to prevent uterine inversion while the other hand exerts sustained downward traction on umbilical cord
Crede maneuver – cord is fixed with lower hand while the uterine fundus is secured and sustained upward traction is applied using abdominal hand

29. How to effectively deliver a baby
Inspect the placenta
Abnormalities of lobulation
Site of insertion of umbilical cord into the placenta
Marginal insertion –inserts into edge of placenta
Membranous insertion – vessels course through the membranes prior to attaching to placental disk
Length (50-60cm)
2 arteries and 1 vein
Single umbilical artery associated with 20% risk of other structural anomalies.