1st Trimester Flashcards
Are early pregnancies a GYN or OB domain why?
GYN
many pregnant don’t make it out of the 1st trimester
the follicles in the ovary are arrested in what stage?
prophase of meiosis I
the LH surge causes the oocytes to complete Meiosis I and begin ____
Meiosis II
When does the production of progesterone from the corpus luteum begin?
just after ovulation
for every primary oocyte ____ mature eggs are produced after LH surge and __ polar bodies are produced
1
3
Where does fertilization occur
in the tubal ampulla
of the 200-500 million sperm that are ejaculated, only ___ sperm reach the secondary oocyte to attempt fertilization
200
the secondary oocyte if fertilized for only __-__ hrs after ovulation
12-24
to fertilize, sperm must get through what 3 layers of the secondary oocyte
- corona radiata (follicle cell layer surrounding oocyte)
- zona pellucida (glycoprotein layer surrounding ovum)
- oocytes cell membrane
To have the ability to pass through the layer of the oocyte, the sperm must be ____ by losing their ____, these are usually lost in the femal vaginal tract
Capacitated
Decapacitation factors
** this must be mimiced for in vitro fertilization to work
Capacitation also causes the ___ to beat more rapidly
flagellum
what chemical reaction occurs when the sperm is exposed to glycoproteins
acrosomal reaction
Where does the acrosomal reaction occure in the oocyte
zona pellucida
the acrosomal reaction Allows sperm plasma membrane to fuse with ovum plasma membrane to…..
drop the sperm nucleus into the ovum’s cytoplasm
What happens when the ovum’s cell membrane fuses with the sperm cell membrane
Meiosis II re-starts at metaphase and completes, creating another polar body
Fusion with sperm triggers changes that prevent ____
polyspermy
The nuclei of sperm and egg are referred to as ____
Each has a ___number of chromosomes, and only one copy of each.
pronuclei
haploid
Prior to the nuclei fusing, each one goes through an __ phase.
The 2 nuclei then fuse, and the single cell is called a ___
S
zygote
implantation and HcG production occurs ___ days after fertilization
7-9
cell division occurs every 12-24 hours
at the 8 cell stage ~ 3 days the cell is called a _____
morula
arrival to the uterus / wall occurs about day 6, now the egg is called a ____
blastocyst
A blastocysts consists of what?
inner cell mass
trophoblast (outer cell)
Does the inner cell mass or trophoblast (outer cell) become the embryo
what does the other thing become?
inner cell mass
the placenta and metal membranes (amnion, chorion)
As the trophoblast gains access to inner layers of endometrium they proliferate and create folds called ___(surface area!)
As these cells contact maternal vascular cells, connection is made between ____ and embryonic villi.
At these sites, two cell layers exist between maternal blood supply and embryonic blood supply.
Maternal capillaries proliferate and gradually coalesce, forming ___.
villi
maternal capillaries
lacunae
Bleeding in the first trimester happens in ___-___% of all pregnancies. Not all will be lost
20% to 25%
Pregnancy loss are ~ __-__% of those who experience first trimester bleeding.
25% -50%
*so 50-75% pregnancies will continue
Risk of pregnancy loss or non-viability increases if …. (20
Bleeding becomes heavy
Bleeding is accompanied with cramping or pain
Risk of pregnancy loss or nonviability decreases significantly (to 3-7%) if: (2)
An intrauterine gestation with + FCA (fetal cardiac activity) is detected
BHCG values rise appropriately for gestational age
What are the DDx of 1st trimester bleeding
Normal intrauterine pregnancy
Threatened abortion
Abnormal intrauterine pregnancy
Ectopic pregnancy
Urine pregnancy test (UHCG or UPT)
Accurate on first day of ____
expected menses
βhCG May become positive as soon as __-__ days after ovulation
6-8
Date of expected menses (@14 days after ovulation) – βhCG is usually ~____ IU/L
100 IU/L
During the first 30 days of pregnancy (~weeks 3-8) What happens to βhCG levels
Doubles every 48-72 hours
The two early pregnancy dx tools include
HCG and US
innocent causes of 1st trimester bleeding
cervical ectropion
implantation bleeding
vaginal infection/irritaiton
implantation is accompanied by bleeding in ___% of women
30%
when does implantation bleeding occur how long does it last?
occurs: 6-12 days after ovulation (22-25 of cylce
lasts ~3 days
what are s/s of implanations bleeding?
meager bleeding (pink or brown coor) painless
the cervix in a cervical ectopy appears _____ because the inner lining of the cervical canal comes out.
raw-looking granular appearance
The lower limit of hCG at which an examiner can reliably visualize pregnancy on ultrasound. It is ___-____ IU/L with vaginal ultrasound and____-___ IU/L with abdominal ultrasound.
1000-2000
5000-6000
The absence of a uterine pregnancy with B-HCG above the discriminatory value signifies an _____
abnormal pregnancy
usually ectopic or incomplete abortion
If β-hCG levels are still below the discriminatory value, what should be done?
serial β-hCG’s and ultrasounds should be done bc it indicated an abnormal pregnancy.
In a normal pregnancy a ___% or greater increase in serum β-hCG levels should be observed every __ hours
66
48
What steps should you take if Bleeding occurs in early pregnancy with unknown location of the gestation
- check serum BHCG
- If it is above the discriminatory zone (DZ), an intrauterine pregnancy should be seen.
- Then do an ultrasound to see if you see the pregnancy.
** if you cent see anything–> assume ectopic
at 5 weeks the BhCG ___ what can be visualized
at 6 weeks the BhCG ___ what can be visualized
at 7 weeks the BhCG ___ what can be visualized
> 1500, gestational lab
> 5200, fetal pole
> 17500, cardiac motion
spontaneous abortion usually refers to the 1st ____ weeks of pregnancy
20
If fetus dies in uterus after 20wks GA, it’s called an ___ or ___
intrauterine fetal demise (IUFD or FDIU) or stillbirth
SAB is likely if..
** know these exist only memorize #1 of Changes in bHCG**
US measurements are
or
Changes in bHCG is
1.
2.
3.
- 5mm CRL, there is no fetal heart rate
- 10mm mean sac diamter, no yolk sac
- 20mm mean sac, no fetal pole
- <15% rise in bhCG over 48 hrs
- gestational sac grwoth <22mm over 5 days
- gestational sac growth <3mm over 7 days
____ is a normally growing early pregnancy, but with vaginal bleeding
bleeding occurs befor 20th week
other definition: bleeding in early pregancy with no pregancy loss
threatened abortion
how is threatened abortion diagnosed
US or BhCG
what are the types of SAB/EPF? (7)
complete incomplete inevitable chemical prenancy blighted ovum/anembryonic pregnancy missed septic
___ is intrauterine pregnancy with cervical dilation & vaginal bleeding
Inevitable:
___ is an cervix open, some tissue has passed
Incomplete:
___: is +βhcg but no sac formed
may account for __-___% of all miscarriages.
Chemical pregnancy
50-75
___ is missed/incomplete abortion becomes infected
Septic:
___ is a total miscarriage without medications or surgical intervention
Complete
___ is when an embryo never formed or demised, but uterus hasn’t expelled the sac
Missed
___ is empty gestational sac, embryo never formed
Blighted ovum/anembryonic pregnancy
__-___% of all clinically recognized pregnancies end as SAB’s (ACOG)*
___% of these occur in the first 12 weeks
10-25
80
Probability of 2 consecutive miscarriages is
5
Chromosomal or non-chromosomal
Up to ____% of SAB’s are due to chromosomal abnormalities
1/2 are trisomies
1/2 are triploidy, tetraploidy, or 45,X0
50
what are the 6 non-chromosomal causes of SAB
Maternal systemic dz infectious factors Endocrine factors abnormal placentation anatomic considerations environmental factors
Maternal systemic disease causes of SAB include….
Antiphospholipid antibody syndrome
lupus
coagulation disorders
Infectious factors of SAB include…. (7)
Brucella chlamydia mycoplasma Listeria toxoplasma malaria TB
Endocrine factors of SAB include….
DM
hypothyroidism
“luteal phase defect” from progesterone deficiency
what are environmental factors that case SAB?
Smoking >20 cigarettes per day (increased 4X)
Alcohol >7 drinks/week (increased 4X)
Increasing age
Management of bleeding without diagnosis of SAB, Pelvic rest (has/has not) been shown to improve outcome
HAS NOT
Management options for dx’d SAB
Uterine evacuation by
- suction (manual/electric)
- medication
conservative tx: many will spontaneously complete on their own
advantages of surgical management of SABs?
ensures products of conception are fully evacuated
minimal anesthesia needed
can often be done in office
women are very satisfied with method
what medication is used in the management of SAB?
Misoprostol
- synthetic prostaglandin
- inexpensive, orally active
