Labor and delivery represent pivotal stages in maternal healthcare, with various factors influencing childbirth experiences and outcomes. Extensive research has explored the concept of self-efficacy in coping with childbirth, revealing a correlation between higher childbirth self-efficacy and a preference for vaginal delivery. Understanding the stages of labor and delivery is paramount in obstetrics, crucial for ensuring the well-being of both mothers and neonates. Research endeavors have predominantly focused on delineating the spontaneous labor curve, a fundamental framework that delineates the progression of labor from the initiation of contractions to childbirth. Investigations have yielded valuable insights into the duration of the active phase of labor among nulliparous women, the second stage of delivery for both nulliparous and multiparous women, and the length of the second stage of labor in women opting for vaginal birth after cesarean (VBAC)

1. Labor and Delivery
Marcela’s Recipe for
Having a Baby:
• 2 cup Mechanics
• 2 cups Hormones
• 3 cup emotional &
physical support
• Mix and Stir with
the three stages of
labor
•Time: 8 - 48 hours
•Makes three: one
new mom, one new
dad and a brand
new baby

2. Parturition
• Birth of the baby
• Both Biological and Social Event
• Expected Day of Delivery
– 266 days (38 weeks) after fertilization
– 280 days (40 weeks) after last menstrual period
• Onset of Labor not completely understood but
we do know it’s about:
1. Mechanical Factors (psst this means muscles)
2. Hormonal Factors (oh yes there are more!!)

3. It’s Like a Marathon:
The Body Prepares
• Training: fitness of mom
and fetus are important
during labor (remember
hypoxia bad!)
• Stretching: Ligaments relax
esp. pubic symphisis making
more room in pelvic brim
• Practice makes perfect:
Braxton-Hicks Contractions
give the top myometrium a
workout, stretch the bottom
muscles and help dilate the
cervix

4. Your Favorite: Hormones!
• Fetal Hormones
• High Estrogen vs.
Progesterone
• Prostaglandins
• Oxytocin
• Relaxin
• All combine for a
POSITIVE feedback
loop

5. On Your Mark, Get Set, Go!
The Onset of Labor
• Fetal Hypothalmus secretes Corticotropin Releasing
Hormone near term which stimulates the
• Fetal Anterior Pituitary to secrete adrenocorticotropin
hormone (ACTH)
• ACTH stimulates fetal adrenal cortex to produce
cortisol
• Cortisol stimulates secretion of estrogen from
placenta, inhibition of P synthesis -> uterine
contractions -> stimulates oxytocin -> hyp
• Fetuses with adrenal hypoplasia are often post-date
and labor is slow to start

6. Estrogen and
Progesterone
• Progesterone
inhibits
contractibility
• Estrogen increases
contractibility
• At 7th month,
estrogen still
increasing but
progesterone drops
off slightly
• High Estrogen:
Progesterone ratio
excites uterus

7. Oxytocin: “The Hormone
of Love” -Michel Odent
• Peptide hormone created in hypothalmus
• Once E:P stimulating contraction,
hypothalmus signaled to send oxytocin to
posterior pituitary
• E and Prostaglandin increase sensitivity of
oxytocin receptors
• Stimulates uterine contraction and breasts
• Administered to stimulate labor as pitocin
• Fun Fact: hormone involved in orgasm!!

10. Two More!!
Prostagladins
• Release stimulated
by estrogen and
oxytocin
• Also stimulates
oxytocin (+ loop)
• Promotes uterine
contractions
Relaxin
• Peptide hormone
produced by the
corpus luteum
• Looses ligaments
• Softens cervix
• Increases # of
oxytocin receptors

12. Three Stages of Labor
• Dilation and
Effacement
• Descent and
Expulsion
• Expulsion of
Placenta

13. Stage One: Dilation
• Intermittent
contractions < 10
minutes
• Cervix dilating and
thinning
• Average 12 hours
primigravidas, 7
hours for
multigravidas

14. Vertex and Transverse
Positions
• Vertex position (head
down) is “normal”
• Uterus contracts
pushing the occiput
bone to put pressure on
cervix to dilate
• Transverse lie is worst
case scenario with
shoulder as presenting
part

15. Breech Presentation

16. Stage Two: Expulsion
• Begins when cervix
fully dilated (10 cm)
• Contractions are
strongest at top of
uterus pushing fetus
downward
• Average 50 minutes
prima, 20 min multi Head Crowing

17. Can You Tell the
Difference?
• Most US hospitals encourage women to deliver in
supine position
• Physiologically worst position because works against
gravity, compresses blood vessels endangering baby
and increases chance of 3rd and 4th degree tears
with episiotomy

18. Working Hard
Mom and Baby
• Pain from contractions comes first from
hypoxia to uterine muscles and then from
stretching and straining
• Contractions intermittent because baby’s
blood supply compromised and fetal HR drops
with every contraction, thus hypoxia can
occur (esp when too much pit is given)
• Baby is an active participant in birth pushing
and negotiating bony structure to get through
birth canal
This Little Guy is All Tuckered Out

19. Stage 3: Placenta
• Uterus contracts reducing
area of attachment
• Separation of placenta
results in bleed and clotting
• Placenta expelled
• Represents stage when
hemorrhage can occur
• Pitocin administered to aid
uterine contraction
• Manual Extraction if retained
• Lasts about 15 minutes

20. Recovery Time
• Contraction of uterus result in
constriction of spiral arteries
(what was their role again?)
• Mother - Father - Baby
Bonding Time: intense period
of hormone release: prolactin,
serotonin, dopamine, the
happy hormones
• In first hour of life, babies can
crawl and self-attach to breast
however babies that are
drugged are almost always too
disoriented to do so
Happy Mom Breastfeeding

21. If All Else Fails
Cesarean Section
• Indications:
– Cord Prolapse
– Tranverse Lie
– Fetal Distress
– Placenta Previa
– Placenta Abruption
– “Failure to Progress”
– VBAC: risk of uterine
rupture
– Cephlo-Pelvic
Disproportion

22. Warning: Midwife
Speaking
• US C-section rate 25-30%
• WHO says >10% unnecessary
• Interventions such as epidurals,
withholding food and water,
supine position increase chance
of C-section
• Hospital settings induce
anxiety, release of adrenaline,
labor STOPS
• Feminist critique: Much of
language used to describe birth
is very unempowering (ie
failure to progess, stubborn
uterus)

23. If we hope to create
a non-violent world
where respect and kindness
replace fear and hatred
We must begin
with how we treat each other
at the beginning of life.
For that is where
our deepest patterns are set.
From these roots
grow fear and alienation
~or love and trust.
~Suzanne Arms
If we want to create a less violent world, we
must begin with birth