pregnancy Flashcards
pregnancy
state of carrying a developing conceptus
Gestation period
time from last menstrual period until birth
~280 days/40 weeks
embryo
conceptus from fertiliation through week 8
fetus
conceptus from week 9 through birth
when oocye is viable, when sperm is viable, and when coitus muct occur
Fertilization
- oocyte viable for 12-24 hours
- sperm is viable 24-48 hours after ejactualtion
- coitus must occur no more than 2 days before and no more than 24 hours after ovulation
fate of sperm
- some leak out after deposition
- some are destoryed by acidic vaginal enviornment
- some fail to make it though the cervix
- some are dispersed in uterine cavity or destroyed by phagocytes
- only a few thouseand out of million reach the fallopian tubes
Capcitated
when the acrosome of the sperm is broken down so the chromosomes in the head of the sperm can be deposited into the ovum
Sperm have… to reach the egg
sperm have olfactory receptors that can follow the chemical trail released by an egg or surrounding cells
Cleavage
rapid mitotic divisions
-first after 36 hours
-after 72 hours morula forms
Blastocyst Formation
-days 4-5 (100 cells) in uterus
-nourished by uterie secretions
-day 8-10 implant into endometrium
implantation
as the endometrium erodeds, the blastocyst burrows into lining and surrounds itself by pool of leaked blood
then enomertial cells cover and seal off implanted blastocyst
if implantation fails, the uterus becomes non-receptive again
-about 2/3 of all zygotes formed fail to implant by end of first week or spontaneously abort
Human Chorionic Gonadotropin (hCG)
-prevents menstration(is secreted by embryo)
-prompts corpus luteum to continue secreation of progesterone and estrogen
-promotes placental development
-declines as placenta begins to secrete progesterone and estrogen
Placenta
-tempoaray organ that originates from both embryonic and maternal tissues
-fully formed and function by end of 3rd month
–provied nutritive, respiratory, excretory, and endocrine functions
what are they, and what do they do?
Germ Layers
endoderm (inner)
-digestive, respiratory systems
mesoderm (middle)
-cardiovascular, musculoskeletal system
ectoderm (external)
-integumentary, nervous system
1st trimester
conception to 12th week
organogensis
building of organs - weeks 5-7
week 5
- formation of the Neural Tube (gives rise to brain and spinal cord)
- first major even of organogensis
- two vessels forming heart have fused
- heart beats 110 bpm
Week 7
- bones begins to replace cartilage
- gonads begin to form
- resembles tadpole or seahorse
- size of a blueberry
Week 8
- enbryo is 1 inch long
- all organ systems are recognizable
- size of a black bean
Week 9
- now referred to as “Fetus”
- beomes more human - looking
Week 11
- Fetus can open/close fists & mouth
Week 12
- End of 1st trimester
- risk of miscarriage decreased
- mom feels better
- 2.5-3 in. size of lime
2nd Trimester
13-27 Weeks
-generally the best part of the gestation period for mother
-mother begins feeling fetus move
weeks 13-15
not necessarily eventful
week 16
- baby can hear you talk
- turn head away from broght light
- size of avacado (5in)
20 weeks
anatomy ultrasound for gender
week 22-23
baby may survive if born at 22-23 weeks with intensive care
end of 6 months
skip
12 in long
week 24-28
surfactant production
-size of cauliflower head
3rd trimester
28-40 weeks
-period of greatest weight gain for fetus
-rapid neurological development
week 32
17-18 in long (pineapple)
week 37
fetus may drop into pelvis
full term
week 39 (best chance for lungs)
baby size when born
not always with in this peramiter
18-20 in, 7-9 pounds (small pumpkin)
1st trimester
what happens to the mother
- tender/swollen breasts
- nausea vomiting
- polyuria, fatigue
- heartburn, constipation
- mood swings
2nd trimester
what happens to the mother
- less nausea/fatigue
- some increase anxiety
- thicker hair/fingernails
- food craving/acersions
3rd Trimester
what happens to the mother
- fatigue & uncomfortable
- Annoyance
- Back Pain
- Difficult sleeping
- Difficulty Breathing
- False contractions
teratogen
factors that may cause sever congenital abnormalities or even fetal death if cross placental barriers and enter fetal blood
microorganisms
-rubella, HIV, Listeria
fetal alcohol syndrome
typified by microcephaly (small head), intellectual disability, and abnormal growth
Nicotine
hinders oxygen delivery to the fetus, imparing normal growth and development
Preeclampsia
dangerous complication of pregnancy that can result in hypertension, edema, & proteinuria (HAP)
Eclampsia
can be caused by preeclampsia
-generalized seizures that can be fatal
-only cure is delivery of baby
Parturition
culmination of pregnancy; giving birth to baby
Labor
series of events that expel infant from uterus
what does incresed placental cortisol do?
triggers maturation of fetal lung, increasing production of surfactant
Effects of Cortisol
leads to rapid increase in estrogen production by placenta
1. prepares cervix for dilation: thinning and softening (effacement)
2. prepares myometrium of uterus for contraction: leads to Braxton Hicks contractions in uterus (false labor)
3. Leads to myometrial contractions: Oxytocin (force of contraction) and prostaglandins (rhythm)
Initation of Labor
- positive feedback mechanism occurs
- child causes greater distension of cervix
- more oxytocin/prosaglandin release
- greater contractile force
Dilation stage
1st of the three stages of labor
- from labor’s onset to fully dilated cervix
- longest stage of labor 6-12 hours or more
- initial weak contractions
-15-30 minutes apart, 10-30 seconds long
-become more vigorous and rapid - cervix effaces and dilates fully to 10 cm
- engagement occurs: head enters true pelvis
Expulsion Stage
2nd of the three stages of labor
- from full dilation to delivery of infant
- strong contraction every 2-3 minutes, each about 1 minute long
- urge to push increaes (in absence of local anesthesia)
- crowning occurs when largest dimension of head distends vulva
-Episiotomy, incision made to widen vaginal orifice, may be done to reduce tearing
Placental Stage
3rd of the three stages of labor
- delivery of afterbirth (placenta and membranes) occurs within 30 minutes after birth
- all placenta fragments must be removed to prevent postpartum bleeding
Expulsion Cont.
define vertex position and breech position
- once head has been delivered, rest of the body is delivered more easily
- vertex position: usual, head-first presentation
-skull dialtes cervix - Breech Position: buttock-first
-Delivery is more difficult; often forceps or C-section (delivery through abdoninal and uterine wall incision) is required
Dystocia
if a woman had a deformed or narrow male-like pelvis, labor can be prolonged and difficult
can possibly result in maternal fatigue and/or fetal brain damage (ex: cerebral palsy or epilepsy)
treatment; cesarean (c) section is preformed
Neonatal period
4 week period immediately aftr birth
Apgar Score
a physcial assesment within 1-5 minutes after birth
0-2 points for each
* activity: muscle tone
* pulse: heart rate
* Grimace: reflexes
* Appearance: color
* Respiration
Score 8-10 means heealthy baby
Milk is produced by…
mammary glands
Colostrum
- an initial fluid - very little produced/needed
- yellow fluid with more protein, Vit. A, minerals, IgA antibodies
- low in fat (“Liquid Gold”)
- 2-3 days later, true milk production begins
Breast Milk Advantages
- Fats and iron are better absorbed
- amino acids are more easily metabolized
- has a host of benificial chemicals, including; IgA, complement, lysozyme, interferon (protect infant from pathogens)
- encouraged bacterial coloization of infant’s gut
- has natural laxitive effect that helps cleanse infant’s bowels of meconium (baby’s first poop), a tarry green-black paste
- can help with mother’s weight loss
