Partution Flashcards
Due date
40 weeks after first day of last menstrual cycle/ 8 weeks after conception
-If you’ve been pregnant before, you’ll probs have an shorter due date –> other factors = race (black), stress, maternal age, and health status
There’s seasonal and regional differences
Babies are usually born bt 4-9 a.m.
How placenta contributes to due date
Releases corticotropin releasing hormone (CRH)
-increases growth of fetal adrenal gland
- increases ACTH from fetal pituitary:
- increases cortisol from fetal adrenal gland –> organ maturation, stimulates placenta for more CRH, stimulates production of fetal PGs for myometrium contraction
- increases androgens from fetal adrenal gland –> placenta conversion to estrogen for myometrium contraction
Recap of E/P roles during pregnancy
P keeps uterus quiet
- inhibits PG synthesis
- inhibits synthesis of oxytocin receptors
- decreases # of Ca channels in uterine smooth muscle cells
E makes the uterus a better contractor
- increases # of oxytocin and PG receptors
- increases PG synthesis
- increases gap junctions bt smooth muscle cells
- soften collagen in cervix
oxytocin: sources and effects
sources = maternal posterior pituitary and placenta
Effects: uterine smooth muscle contraction –> increases PG release from uterus
Labor induction: how and why
How:
- break amniotic membrane
- PGs via IV, oral, injections
- Pitocin = synthetic oxytocin IV
- mechanical stimulation of vagina, cervix, uterus, nipples –> increases oxytocin release from posterior pituitary
Why:
- 2+ weeks overdue
- amniotic sac burst w/o labor risks infections (baby and mom) and comes with other risks (diabetes or hypertension)
How long does labor last?
Delivery ususally happens w/ni 24 hrs
- 8-14 hrs in primiparous women
- 4-9 hrs in multiparous women
Stage 1: cervical effacement and dilation
uterine contractions
- regular pattern
- increase in frequency (5-20 mins to 1-3 mins)
- increase duration (30-60 s)
- increase in force
- start high and move lower
cervical effacement = thinning and retraction toward uterus
cervical dilation to 10 cm
Signs of the beginning of labor
“bloody show” = loss of cervical mucous plug + blood
“Water breaking” = tear in amniotic sac –> trickle vs gush
transition phase
contractions
- painful –> may cause nausea and vomitting
- cramping and trembling of legs
- “back labor” depends on position of back of baby’s head (toward sacrum)
- urge to push with baby’s head pushing on pelvic floor = “engagement”, leading to stage 2
Stage 2: fetal expulsion
30 min - 2 hrs
-after max cervical dilation
active pushing
- contract abdominal muscles to assist in pushing head down into birth canal
- “crowning” = appearance of head, which may come with “ring of fire”
- “conehead baby” –> head is 3” bigger than cervical opening, so baby’s head has fontanels that allow skull bone movement –> reshapes in a few days
7 movements of birth
- Engagement: widest part of head has passed into pelvic outlet
- Descent: movement of head through bony pelvis
- flexion of fetal head : chin toward chest
- Internal rotation: movement of head and body from side-to-side and front-to-back
- Extension of fetal head: after head passes throgh the pelvis, neck is under pubic arch –> birth of head/face/chin –> suction mucus and amniotic fluid from nose/mouth and chem for umbilical cord around neck
- external rotation for shoulders: move head 90 degrees to face maternal thigh
- expulsion: baby’s body follows rotation of head and shoulders are born
Episiotomy
- local anesthetic
- prevention of vaginal tears with easier healing (perineal tears = 1st- 4th degree)
- incision made in perineum (midline is easier repair, but increased risk of tearing into anus) (mediolateral is more painful and more difficult to repair)
decreased practice -11% of vaginal births
-baby’s shoulder is stuck
0abnormal fetal heart rate detected
-forceps or vacuum extraction
Stage 3: placental expulsion
Placenta = afterbirth –> separates from uterine wall in, like, 10 mins
Natural expulsion (up to an hour) -oxytocin facilitation during breastfeeding --> contraction of uterus and inhibits uterine bleeding
Active management (1-5 mins)
- drugs that cause uterine contractions and prevent bleeding
- cord traction and early cord cutting
- con for baby: loses blood to placenta (hypotension and anemia)
Placenta and umbilical cord
Placenta
- anti-inflammatory, antibacteria and anti-scarring properties
- if preserved right, can maintain presence of cells and growth factors
- Donate to be used in reconstructive procedures to promote healing, treatment of burns and wounds, ophthalmologic use
Umbilical cord blood
- hematopoitic stem cells
- blood cells- RBC, WBC, platelets
- transplants for blood cancers (leukemia/lymphoma) –> restore bone marrow after radiation and chemotherapy destruction
