Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

OBGYN > OB first trimester registry review > Flashcards

OB first trimester registry review Flashcards

1
Q

First trimester embryology

A

Zygote –> morula –> blastocyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

First trimester

A

Weeks 1-12

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Fertilization

A

Usually occurs in the ampulla, within 24 hrs of ovulation (~day 14 of 28 day cycle)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Zygote

A

A fertilized egg, undergoes rapid cell division

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Morula

A

Cluster of cells formed 3-4 days after fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Blastocyst

A

First time cell differentiation occurs by day 5

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Trophoblast

A

Outer ring of trophoblastic cells that begin to produce hCG. Will eventually become the chorion and placenta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Embryoblast

A

Inner cell mass that will develop into embryo, amnion, cord, yolk sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

hCG released by trophoblast

A

Maintains corpus luteum therefore maintaining endo via progesterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Decidualized (decidual reaction)

A

Endometrium prepares for implantation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Implantation

A

Occurs 7-9 days after fertilization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Chorionic villi

A

Finger like projections of trophoblast that form links into decidualized endo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Yolk sac

A

Primary sac regressed by day 28 from LMP, secondary sac replaces

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

hCG levels post implantation

A

Double every 48 hours until week 9

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Endometrium @ 4 weeks gestation

A

Multilayered appearance due to increased progesterone (decidualized), possible tiny anechoic sac

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

5 weeks gestation

A

-1,000-2,000 hCG level
-GS seen by transvaginal
-double decidual sign confirms 2 layers of decidua

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

hCG level for transabdominal GS seen

A

3,500 mIU/mL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

2 layers of decidua

A

Capsularis and parietalis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Mean sac diameter (MSD)

A

L + H + W/ 3
Grows 1mm per day

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Gestational sac first seen with MSD

A

10mm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Extraembryonic coelem

A

Space of the chorionic cavity between the amnion and chorion where the gestational sac is found

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

5.5 weeks gestation

A

Gestational sac and yolk sac appear and are the first definitive sign of an IUP

23
Q

Secondary yolk sac

A

-Responsible for producing AFP, angiogenesis, hematopoiesis
-Is round, anechoic with thin echogenic rim measuring <6mm
-Connects to embryo

24
Q

Vitelline duct

A

Duct that connects the yolk sac to the embryo, consists of 1 artery and 1 vein

25
Q

Angiogenesis

A

The process of new blood vessels forming from existing blood vessels

26
Q

Hematopoiesis

A

The production of blood cells and platelets

27
Q

Enlarged yolk sac

A

Indicates impending demise (double bleb)

28
Q

Double bleb sign

A

Large yolk sac next to amnion

29
Q

6 weeks gestation

A

Embryo now seen within amniotic cavity adjacent to yolk sac. Must be seen by MSD 25mm. Fetal pole grows 1mm per day after 6 weeks

30
Q

Crown rump length (CRL)

A

MOST reliable estimation of gestational age in first trimester

31
Q

Fetal cardiac of fetus

A

-Must be noted by 5mm CRL, possibly earlier
-Approx 100bpm increasing to 140 later in 1st trimester

32
Q

7 weeks gestation

A

Formation of limb buds and fetal head appears larger than body

33
Q

8 weeks gestation

A

Cystic structure noted within head-rhombencephalon

34
Q

Rhombencephalon

A

Eventually 4th ventricle

35
Q

9-12 weeks gestation

A

Normal for physiological bowel herniation migration of midgut and bowel at base of umbilical cord–> should be completed by 12 weeks

36
Q

10 weeks

A

No longer an embryo–> FETUS

37
Q

11+ weeks gestation

A

Fetal limbs and facial profile/cranium clearly evaluated and normalized

38
Q

Lateral ventricles

A

Filled with echogenic choroid plexus on either side of falx cerebri

39
Q

Placenta and umbilical cord

A

Well defined, crescent shaped and slightly echogenic mass of the tissue. Formed by decidua basalis and chorion frondosum

40
Q

Decidua basalis

A

Maternal component of placenta and umbilical cord

41
Q

Chorion frondosum

A

Fetal component of placenta and umbilical cord

42
Q

Hormones produced by placenta and umbilical cord

A

Several hormones + pregnancy-associated plasma protein a (PAPP-A)

43
Q

First trimester screening

A

-11-13w6d
-Primarily for Trisomy 21 and 18
-Evaluate NT measurement + hCG + PAPP-A

44
Q

Nuchal tranlucency

A

Fluid filled layer between the fetus and the skin layer, SHOULDN’T measure >3mm

45
Q

Enlarge NT associated with

A

Trisomy 18, trisomy 21, trisomy 13, turners, cardiac defects; require karyotyping

47
Q

Karyotyping

A

Genetic test that analyzes the number, shape, and size of chromosomes in a sample of cells

48
Q

Guideline for 1st trimester screening

A

-CRL between 45-84mm
-Midsagittal view
-Fetal head in neutral position
-Magnified image, head occupies most of image

49
Q

Midsagittal view landmarks

A

Rectangle shaped palate and mandible, nasal bone, thalamus, and brain stem

50
Q

NT measurement

A

INNER TO INNER at widest section in the back of neck when fetus is in neutral position, include entire fluid section but not skin

51
Q

Chorionic cavity

A

Area between amnion and chorion, typically fuse during first trimester but fully fused by 16 weeks

52
Q

Abnormal NT

A

Pocket of fluid visibly enlarged

OBGYN (17 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions