5.4: pregnancy & childbirth

pregnancy

gestation

• measures from ____

• __ trimesters

changes mediated by hormones

• secreted ___

• corpus luteum ___, ____ takes over

gestation

• measures from 1st day of last menstrual period → 40 weeks

• 3 trimesters

changes mediated by hormones

• secreted by corpus luteum & placenta

• corpus luteum degenerates during weeks 7-17, placenta takes over

hormones of pregnancy

human chorionic gonadotropin (HCG)

• secreted by ___

• detected by ___

• HCG peaks ~___ weeks, then low for remainder of pregnancy

• stimulates growth of ___

  • atrophies w/o HCG

human chorionic gonadotropin (HCG)

• secreted by embryo/ placenta after implantation

• detected by home pregnancy test

• HCG peaks ~10-12 weeks, then low for remainder of pregnancy

• stimulates growth of corpus luteum

  • atrophies w/o HCG

hormones of pregnancy

estrogen

• 30x usual amount secreted by end of ___

• stimulates ___

  • enlargement of breasts & uterus

  • growth of mammary ducts

  • increased elasticity/ flexibility of pelvic joints

estrogen

• 30x usual amount secreted by end of gestational period

• stimulates tissue growth

  • enlargement of breasts & uterus

  • growth of mammary ducts

  • increased elasticity/ flexibility of pelvic joints

hormones of pregnancy

progesterone

• suppresses ___

• suppresses __

• promotes ___

• stimulates ___

progesterone

• suppresses secretion of gonadotropins: prevents ovulation & menstruation

• suppresses uterine contractions

• promotes proliferation of functional layer: forms maternal placenta

• stimulates development of mammary glands

hormones of pregnancy

.

hormones of pregnancy

oxytocin

• stimulates __

• stimulates ___

relaxin

• relaxes __

• stimulates ___

• promotes __

parathyroid hormone

• maintains __

aldosterone

• increases __

oxytocin

• stimulates uterine contractions

• stimulates contractions of myoepithelial cells in mammary glands

relaxin

• relaxes pelvic ligaments and pubic symphysis

• stimulates growth of functional layer

• promotes growth of blood vessels in uterus

parathyroid hormone

• maintains maternal blood calcium levels

aldosterone

• increases maternal blood volume

anatomical changes

• uterus greatly ___

  • abdominal organs ___

• increasing ___

  • lordosis can develop:

• enlargement of ___

• uterus greatly increases in size

  • abdominal organs crowded up against diaphragm: ribs flare

• increasing abdominal projection changes center of gravity

  • lordosis can develop: increased curvature of lumbar spine

• enlargement of breasts

physiological changes: digestive system

nausea

• potentially from decreased ___

• potentially adaption to __

• potentially from elevated __

• hyperemesis gravidarum:

nausea

• potentially from decreased intestinal motility

• potentially adaption to protect fetus from ingested toxins

• potentially from elevated hormones

• hyperemesis gravidarum: severe nausea and vomiting that may require hospitalization

physiological changes: digestive system

• constipation: ___

• heartburn

  • enlarged uterus compresses stomach

  • ___ relax lower esophageal sphincter

  • costigan et al 2006 research showed: heartburn severely associated with newborn hair volume

• constipation: reduced intestinal motility

• heartburn

  • enlarged uterus compresses stomach

  • relaxin & estrogen relax lower esophageal sphincter

  • costagin et al 2006 research showed: heartburn severely associated with newborn hair volume

physiological changes: circulatory & urinary system

• ___ increase 30-40%

• aldosterone promotes ___

  • can lead to edema

• ___ increases 50%

  • disposal of increased maternal & fetal wastes

• growing uterus compresses bladder: more frequent ___

• blood volume & cardiac output increase 30-40%

• aldosterone promotes water & salt retention

  • can lead to edema

• glomerular filtration rate increases 50%

  • disposal of increased maternal & fetal wastes

• growing uterus compresses bladder: more frequent micturitioin reflex

phsiological changes: integumentary system

• abdominal skin stretches

  • expansion of abdomen

  • fat disposition

• stretch marks: ___

• linea negra (formation of line down the stomach), chloasma (darkening of cheeks, chin, forehead): due to ___

• abdominal skin stretches

  • expansion of abdomen

  • fat disposition

• stretch marks: tearing of subcutaneous connective tissue

• linea negra (forms down center of stomach), chloasma (darkening of cheeks, chin, forehead): due to increased melanocyte activity darkens some areas of skin

gestational diabetes

• develops 1-3% of pregnant women

  • due to ___

• insulin insensitivity

  • __& __

• risk of excessive fetal size

  • increased ___ risk

• usually controlled through diet & exercise

• often reverses after delivery of infant

  • but 40-60% develop T2D w/ 15 years

• develops 1-3% of pregnant women

  • due to hormonal changes & placental physiology

• insulin insensitivity

  • hyperglycemia (elevated blood glucose), glucosuria (reabsorption of glucose impaired)

• risk of excessive fetal size

  • increased C section risk

• usually controlled through diet & exercise

• often reverses after delivery of infant

  • but 40-60% develop T2D w/ 15 years

childbirth

• parturition: ___: usually within 15 days of due date

• fetus normally turns into ___ in 7th gestational month

• childbirth begins with ___

• parturition: final stage of pregnancy: usually within 15 days of due date

• fetus normally turns into vertex position in 7th gestational month

• begins with onset of labor

initiation of labor

• largely triggered by ___

  • surge in ____ triggers ___

  • corresponding surge in placental estrogen: ___

• rising estrogen/ decreased progesterone

  • prepares cervix for ___

  • prepares myometrium for ___

    • formation of gap junctions

    • Braxton Hicks contractions

  • increases sensitivity of ___

    • induce true labor contractions

• largely triggered by fetal hormones

  • surge in fetal cortisol in final weeks triggers final maturation of lungs

  • corresponding surge in placental estrogen: weakens action of progesterone

• rising estrogen/ decreased progesterone

  • prepares cervix for dilation

  • prepares myometrium for contraction

    • formation of gap junctions

    • Braxton Hicks contractions (practice contractions of the uterus)

  • increases sensitivity of myometrium to oxytocin & prostaglandins

    • induce true labor contractions

labor contractions

• begins ~30min apart

• strongest in ___, weaker near ___: pushes fetus downwards

• oxytocin

  • stimulates ___

  • stimulates ___

• positive feedback mechanism

  • uterine ___

  • neuroendocrine reflex: ___

  • oxytocin induces ___

• begins ~30min apart

• strongest in fundus, weaker near cervix: pushes fetus downwards

• oxytocin

  • stimulates myometrium to contract

  • stimulates fetal tissue to secrete prostaglandins

• positive feedback mechanism

  • uterine contractions push fetus down: stretches cervix

  • neuroendocrine reflex: oxytocin released in response to stretch

  • oxytocin induces uterine contractions

induced labor

• stimulation of contractions prior to onset of labor

• frequently in response to ___

• pitocin: ___

• increased risk of ___

• stimulation of contractions prior to onset of labor

• frequently in response to post-term pregnancy, premature rupture of amniotic membranes, uterine infection, preeclampsia

• pitocin: synthetic oxytocin administered to progress labor

• increased risk of C section or post-delivery uterine bleeding

labor: dilation stage

• longest stage

• contractions 15-30 min apart, last for 10-30 seconds

• dilation (widening) of ___ & effacement (thinning) of ___

  • from pressure of ___

  • maximum diameter of 10cm

• engagement: ___

• longest stage

• contractions 15-30 min apart, last for 10-30 seconds

• dilation (widening) of cervical canal & effacement (thinning) of cervix

  • from pressure of fecal head w/ each contraction

  • maximum diameter of 10cm

• engagement: infants head begins to descend through birth canal

dilation

.

.

epidural

• local anesthetic to ___

• reduced sensation to ___

• may cause drop in ___: IV fluids given

• local anesthetic to nerves of lumbar spinal cord

• reduced sensation to lower body

• may cause drop in blood pressure (bc sympathetic innervation to blood vessels decreases & they vasodilate): IV fluids given

labor: expulsion stage

• cervix fully ____

• typically 1-2 hrs at 1st birth, shorter for subsequent births

• strong contractions every 2-3 min, last ~1 min

• crowning: ___

• cervix fully dilated

• typically 1-2 hrs at 1st birth, shorter for subsequent births

• strong contractions every 2-3 min, last ~1 min

• crowning: top of baby’s head is visible

caesarian section

• surgical delivery of baby through maternal abdominal wall

  • due to health concerns, large fetal size, adverse fetal position, multiple births

• incision made through fat, skin, abdominal fascia, peritoneum, uterus, amniotic sac

  • abdominal muscles retracted

• longer recovery time, increased risk of complications than vaginal delivery

.

labor: placental stage

• uterus continues to ___

  • contractions of myometrium ___

• placenta & amniotic sac (afterbirth) ___

• uterus continues to contract: placenta detaches

  • contractions of myometrium compress blood vessels (prevent excess bleeding)

• placenta & amniotic sac (afterbirth) expelled