Labor and DeliveryMarcela’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

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!!)

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

Your Favorite: Hormones!

• Fetal Hormones• High Estrogen vs.

Progesterone • Prostaglandins • Oxytocin • Relaxin • All combine for a

POSITIVE feedback loop

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

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

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!!

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

Three Stages of Labor

• Dilation and Effacement

• Descent and Expulsion

• Expulsion of Placenta

Stage One: Dilation

• Intermittent contractions < 10 minutes

• Cervix dilating and thinning

• Average 12 hours primigravidas, 7 hours for multigravidas

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

Breech Presentation

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

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

Working HardMom 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

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

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

If All Else FailsCesarean Section

• Indications:– Cord Prolapse– Tranverse Lie– Fetal Distress– Placenta Previa– Placenta Abruption– “Failure to Progress”– VBAC: risk of uterine

rupture– Cephlo-Pelvic

Disproportion

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)

If we hope to createa non-violent worldwhere respect and kindnessreplace fear and hatred

We must beginwith how we treat each otherat the beginning of life.

For that is whereour deepest patterns are set.

From these rootsgrow fear and alienation~or love and trust.

~Suzanne Arms

If we want to create a less violent world, we must begin with birth