First Trimester Flashcards
When does ovulation occur?
At the beginning of the third week after the first day of the last LMP
During what weeks are the conceptus period?
Weeks 3-5
During what week and days does early development of the conceptus begin?
Week 3 (days 14-21)
Ovulation and fertilization of the ovum occurs during what day?
Day 14
What days does the zygote traverse the fallopian tube?
Days 14-18
The morula enders the uterus during what day?
Day 18
The blastocyst cavity and inner cell mass form during what days?
Days 18-21
What happens during days 18-21?
Blastocyst cavity becomes the primary yolk sac and amniotic formation begins
Implantation of the blastocyst in the uterine wall occurs during what week and days?
Week 4 days 21-28
The fluid filled space surrounding the developing embryo is called?
The choronic cavity
When the amnion and yolk sac are visualized within the chorionic cavity this finding is called?
Double bled sign
At the beginning of the 4th week the gestational sac should be around how many mm in diameter?
1 mm
Name the 3 primary germ layers of the trilaminar disc
1) Ectoderm
2) Mesoderm
3) Mesoderm
What forms within the embryonic plate between the amnion and secondary yolk sac?
Notocord
The notocord induces development of the early embryo and later develops into what?
The vertebral bodies of the spinal column
_______ is the formation of the neural plate and neural tube and somites, which develop into the central nervous sytem
Neurulation
What day does neural tube formation begin?
Day 35
During what day does the closing of the rostral end of the neural tube occur?
Day 40
During what day does closing of the caudal end of the neural tube occur?
Day 42
________ and _________ is the formation of primitive blood cells and blood vessels, heart and placental vascularity
Angiogenesis and hematogenesis
The embryonic period happens during what weeks?
Weeks 6-10
what happens during the embryonic period?
Formation of all permanent internal and external structures
During what week of gestation is the formation of the heart complete?
Week 8
During what week of gestation is the formation of the peripheral vascular system complete?
Week 10
During what week of gestation does the primitive gut form
week 6
Herniation of the midgut into the umbilical cord happens during what weeks of gestation?
Weeks 8-12
Separation of the rectum from the urogenital sinus happens during what week of gestation
Week 8
Perforation of the anal membrane happens during what week of gestation
Week 10
Formation of the primitive kidney in the pelvis and ascension into the abdomen happens during what week of gestation?
Week 8
During what week of gestation are the kidneys in adult position?
Week 11
At how many weeks is genitalia able to differentiated from male and females?
Week 14
The formation of limb buds happens during what week of gestation?
5.5-6 weeks
At how many weeks do digital rays develop and the arms are bent at the elbow?
7.5-8 weeks
When does the clavicle begin to ossify?
8 weeks
_______ means to change into bone
Ossify
At how many weeks does the mandible, palate, vertebral bodies, and neural arches begin to ossify?
9 weeks
The long bones begin to ossify at how many weeks?
11 weeks
The earliest sonographic sign of pregnancy has been described as the focal thickening of the echogenic decidua at the site of implantation is called
Decidual thickening
What is considered to be the first definitive sign of pregnancy?
Gestational sac
The fluid filled gestational sac is first visible at about how many weeks?
4.5-5 weeks
The MSD of _____ mm can be visualized endovaginally
2-3 mm
What appears as a small fluid collection surrounded by an echogenic rim?
The gestational sac
Where is the normal position for the gestational sac?
in the upper to mid uterus
Where would a decidual cyst be located?
At the Endometrial myometrium junction
The sonographic presence of a small GS within the decidua at approximately 4-4.5 weeks with a MSD of approximately 2mm is known as what sign?
Intradecidual sign
To distinguish a true intradecidual sign form a decidual (endometrial) cyst, you make be sure that the GS is directly adjacent to what structure?
Endometrial canal
The echogenic ring formed by the decidua vera and decidua capularis is called what?
Double decidual sign
The double decidual sac sign is surrounded by 2 echogenic rings. The outer ring is called the?
Decidua
The double decidual sign is surrounded by 2 echogenic rings. The inner ring is called the?
Chorion
After how many weeks is the GS measurement no longer used?
7 weeks
The ______ is the first structure visualized within the GS
yolk sac
What is spherical in shape with a sonolucent center and clearly defined echogenic wall?
yolk sac
_________ occurs in the wall of the YS in the 5th week before the liver takes over that function at about the 8 week.
Hematopoiesis
The production of blood cells is called what?
Hematopoiesis
The double bleb sign is no longer visible by how many weeks?
7 weeks
An embryo is often visualized at how many weeks?
5-5.5 weeks
Cardiac activity for an embryo is detected between how many weeks?
5 and 6 weeks
what is the normal range of bpm between 5 and 6 weeks gestation?
100-115
The mean heart rate increases to ____bpm by 9 weeks
140
A heart rate of less than ____ bpm before 6.2 weeks is consistent with a potential miscarriage
100
A heart rate of less than ______ between 6.3 and 7 weeks is consistent with a potential miscarriage
120
The amnion grows to fill the chorionic cavity by approximately how many weeks?
12-16 weeks
Spotting, bleeding, or cramping in the first trimester with a closed cervical os is defined as?
Threatened abortion
The ______ _______ secretes progesterone to support pregnancy until the placenta takes over the hormonal function
corpus luteum
The corpus luteal cysts usually regresses or decreases in size at approximately how many weeks?
16-18 weeks
What type of abortion occurs when all the gestational tissue including the embryo has passed out of the uterus and the uterine cavity is empty?
Complete abortion
If gestational tissue remains within the uterus and bleeding persists this is described as what type of abortion?
Incomplete abortion
If a gestational sac is present in the uterus but no embryo is identified in a sac large enough to require one, the condition is called
Blighed ovum
________ within the uterine cavity and outside the gestational sac is a marker for an increased risk of miscarriage
Blood
An _______ pregnancy is one that occurs outside the uterine cavity
Ectopic
What is considered to be the gold standard for the diagnosis of ectopic pregnancy?
Laparoscopy
The clinical presentation associated with ectopic pregnancy includes the “classic triad” which are what ?
1) pain
2) bleeding
3) palpable adnexal mass
Where is the most common place for an ectopic pregnancy to occur?
In the ampullary portion of the fallopian tube
Where is the second most common place for an ectopic pregnancy to occur?
In the isthmic or interstitial portion of the fallopian tube
______ is considered to be a nonspecific finding for ectopic pregnancy
Fluid
