Normal First Trimester

Front 1

Ovulation

Back 1

Occurs the 14 day of menstrual cycle. The ovum is release from a graafian follicle into the fallopian tube.

Front 2

Fertilization

Back 2

Occurs 24-36 hours after ovulation.
Fertilization occurs in the ampula of and cleavage begins.

Front 3

Cell Division Stages

Back 3

-Gamete
-Zygote
-Blastomere
-Marula
-Blastocyst

Front 4

Gamete

Back 4

Female and male reproductive systems.

Front 5

Zygote

Back 5

Single fertilized ovum

Front 6

Blastomere

Back 6

Fertilized ovum at 2-cell and 4 cell stage located in the ampulla of the fallopian tube.

Front 7

Morula

Back 7

Mass of dividing cells located in the isthmus of the fallopian tube

Front 8

Blastocyst

Back 8

Organized collection of cells which implants in the uterus 7-10 days after ovulation.
The Outer lining has trophoblastic tissue which produce HCG to maintain the corpus luteum cyst.

Front 9

Blastocele

Back 9

An inner fluid filled cavity which contain an inner cell mass which will become the yolk sac, amnion, embryonic disk.

Front 10

Human Chorionic Gonadotropin

Back 10

HCG is a glycoprotien which is produced by trophoblastic tissue and later by the placenta.
Detectable through maternal serum and urine.
Detectable 7 to 10 days after fertilization.
Doubles every 2-3 days, plateaus 8-9 weeks.
Dectable in two ways Qualitative(negative and positive urine test)
Quantitative (provides levels of HCG in blood stream)

Front 11

Primitive Germ Layers

Back 11

Endoderm-(inner) becomes the GI & respiratory system.
Mesoderm-(middle)become musculoskeletal system and circulatory system
Ectoderm-(outer) brain,skin, nervous system.

Front 12

Decidualized Endometrium

Back 12

Decidual Basalis- developed where Blastocyst implants; matetnal contribution to the placenta
Decidual Capsularis- surrounds and cover Blastocyst
Decidual Parietalis- results from hormonal influence on uninvolved endometrial tissue

Front 13

Placenta

Back 13

Has both maternal and paternal components
Decidual component is from the Decidual Basalis
Paternal component is from trophoblastic tissue

Front 14

Chorion Frondosum

Back 14

Choronic villis developed by 5 weeks LMP.
Choronic villis with connections with decidual Basalis becomes the chorion fondosum, the fetal part of the placenta.

Front 15

Membranes

Back 15

The chorion is the fetal contributions to the placenta proliferation.
The remainder is stretch to fit the gestation sac.
The Amnion forms the inner cell mass, the remainder is stretch to fit the chorion.
The amnion and chorion begins to fuse by the middle of the first trimester .
Fusion is complete by 12-16 weeks

Front 16

Hemodynamic Changes

Back 16

Trophoblastic tissue provides the developing embryo with oxygen and nutrients.
Doppler spectral wave form is high velocity low resistance flow.

Front 17

Gestational Sac

Back 17

The first sonographic evidence that a normal intrauterine pregnancy is present. 5week LMP
Normal Songraphic Finding
- sac can be round, oval or tear dropped
- located in uterine fundus or mid-uterus
-double decidual ring
-echogenic intact borders
-should be measured inner-inner
-grows 1mm per day
-ys should be present when MSD reaches 8mm TV.

Front 18

Yolk Sac

Back 18

Yolk sac is the first structure seen within the GS.
Seen when MSD reaches 8mm TV and 20mm TA
Measured inner-inner
Connected to the embryo by the vitelline duct.

Front 19

What is considered an abnormal Yolk Sac?

Back 19

When diameter is > 5.6mm between 5 to 10 weeks

Front 20

Crown Rump Length

Back 20

The embryo should be seen sonographically when MSD reaches 16mm TV, and 25mm TA.
The embryo grows 1mm per day
Most accurate measurement for dating 1st trimester pregnancy.

Front 21

Midgut Herniation

Back 21

The midgut herniates in the umbilical cord at around 9 weeks and return back to the abdominal cavity at 12 weeks.
The herniation is necessary for development of the abdominal vescera.