Human Embryology Test #3 Doroski

Napro success rates

-live births/woman is greater than with IVF

-Napro used after IVF fails is still more successful

Napro advantages

-lower risk of multiples compared to ART

-no observed risk of OHSS

-lower cost than ART

MIscarriage frequency

-estimates vary widely (may be from 3.5% to 70% of pregnancies; likely close to one- third)

-most likely in first trimester (most common in first 3 weeks)

Miscarriage risk factors

-chromosomal abnormalities

-previous miscarriages

-advanced maternal age

-infertility

-endometriosis

Naprotechnology (restorative reproductive medicine)

reproductive medicine designed to cooperate with reproductive system

-heals defects

-promotes healthy functioning of body

-general procedures: charting, nutrition, medications, surgery

Charting

allows identification of reproductive pathologies, aids medical evaluation and treatment, conjugal union can be timed to overcome infertility

Nutrition

some nutrients can hinder fertility at low or high levels, improved diet can aid fertility

Medications

normal hormonal response may be restored, may be used to promote sperm production or ovulation

Surgery

removal of abnormal tissues, restoration of blocked reproductive ducts

Napro disadvantages

-longer wait for pregnancy

miscarriage (spontaneous abortion)

loss of pregnancy by 20th week (fertilization age)

stillbirth

loss of pregnancy after 20th week

Probable underlying cause for miscarriage

abnormal follicle development

-causes low estrogen

-causes low progesterone

ART for miscarriage

-does not identify underlying problem

-low success rate

Napro and miscarriage

can predict miscarriage

-identifies underlying problem

-higher success than IVF

-treatment can begin before a miscarriage happens

premature birth

birth 3 weeks before duedate

-occurs before the 35th developmental week

Bilaminar embryo

inner cell mass forms two germ layers

epiblast

cell layer closer to trophoblast

hypoblast

cell layer farther from trophoblast

amnion

a thin sac surrounding the conceptus proper

amniotic fluid

fluid filling amnion

yolk sac

makes blood for embryo

primitive streak

line down the middle of the embryo where cells group together,

source: epiblast

trilaminar embryo

an embryo with three germ layers formed by gastrulation

labor

the process of birth, occurs approx. 38 weeks after fertilization

location of fetus

presentation, position, station

presentation

part of fetus lying over the cervix, the first part delivered

vertex presentation

top of head is presenting, most common and safest presentation

breech presentation

lower areas are presenting, can endanger the baby, body may be delivered before head can exit

position

direction that baby's head is pointing

occipital bone

bone of the bacl of the skull

occiput anterior (OP)

back of the skull toward the chest, most favorable and common position

Occiput posterior (OP)

back of the skull toward the back, more painful than OA

Timing compared to due date

-small minority born on due date

-about half are born within one week of due date

-vast majority come within two weeks of due date

possible signs of approaching labor/pre labor

-back ache

-lower abdomen cramps

-frequent, soft bowel movements

nesting urge

a strong desire to complete preparation for the baby; accompanied by a burst of energy

dilation stage

stage of labor when progressing contractions begin, ends when cervix is completely dilated

events:

-progressing contractions begin

-cervix effaces

-water breaks

progressing contractions

contractions that increase in strength, length, and frequency

oxytocin

hormone that promotes contractions

pitocin

synthetic oxytocin

Epidural side effects

-decreases oxytocin release

-may lengthen labor

-decreases likelihood of vaginal delivery

-may increase difficulty in starting breastfeeding

expulsion stage

stage when birth occurs

episiotomy

cutting of perineum

perineal massage

massage of inside of perineum, intended to prevent tearing, may be beneficial for first vaginal birth only

placental stage

birth of the placenta

meconium

the first few bowel movements of the newborn

prelabor

stage with non progressing uterine contractions, not actually part of labor

nonprogressing contractions

contractions that do not increase in intensity, frequency, or duration; may bring cervix forward, ripen, and efface it

dizygotic twins/ fraternal twins

twins from two zygotes, caused by two oocytes ovulated and both fertilized

monozygotic twins/ identical twins

twins from a singular zygote, caused by an embryo dividing into two embryos

Conjoined twins/Siamese twins

twins that are physically joined,

caused by separation of monozygotic twins

mirror image twins

twins with mirrored features

SCNT

somatic cell nuclear transfer

SCNT variations

pronuclear transfer (PNT)

maternal spindle transfer (MST)

altered nuclear transfer

pronuclear transfer

Clones zygote

Steps:

- Remove zygote 2 pronuclei

- Add zygote 1 pronuclei to zygote 2

- Promote fusion

maternal spindle transfer (mst)

no clone created

steps:

-removes oocyte 2 nucleus

-add oocyte 1 nucleus to oocyte 2

-fertilize new oocyte

Altered Nuclear Transfer (ANT)

steps:

-remove oocyte nucleus

-alter somatic cell nucleus

-add altered somatic cell nucleus to oocyte

prevents creation of new organism to ethically harvest stem cells

Concerns of Altered nuclear transfer

-May create an organism with a severe disability

-If a disabled human organism is created this technique would be illicit

-Research on this technique may not be ethically possible

tetraploid complementation

steps:

-fuse cells of two normal zygotes

-grow to blastocyst stage

-inject diploid inner cell mass cells into tetraploid inner cell mass

-grow embryo

diploid

having two sets of chromosomes (somatic cells are diploid, gametes are not)

tetraploid

having 4 sets of DNA

chromosome

an organized strand of DNA, found in the nucleus of the cell, humans have 23 chromosomes (1 set = 23)

reproductive cloning vs. therapeutic cloning

reproductive: cloning used for for reproduction (using SCNT)

therapeutic: used for therapies (also uses SCNT)

somatic cell nuclear

clones donor of somatic cell

types: honulu technique

roslin technique

honolulu techniques

steps:

-remove somatic cell nucleus

-add somatic cell to nucleus to ooyte

roslin technique

steps:

-remove oocyte nucleus

-put cells near each other and shock them to promote fusion

somatic cell nuclear

differences between clone and original

-x chromosome inactivation pattern

-would create random differences in a female chrome

-uterine enevironment