Gu Path - 10 - Obstetrics Pathology

Front 1

Normal pregnancy

Back 1

Fertilized egg encounters the secretory endometrium. Endometrial implantation occurs. Trophoblasts produce HCG, while the corpus luteum still persists, and menstruation does not occur

Front 2

Trimesters of pregnancy

Back 2

1st - 13
2nd - 14-27 weeks
3rd- 28-40 weeks

Front 3

Complications of the first trimester

Back 3

Spontaneous Abortion : Threatened(preg and bleeding), missed(dead w/o miscarriage) or incomplete

Ectopic pregnancy
Blighted Ovum

Front 4

2nd TM complications

Back 4

Less common than 1st and 3rd

Front 5

3rd TM complications

Back 5

Abruptio Placenta
Placenta Previa
Hydrops fetalis
Fetal distress
Fetal death in utero
Pre-Eclampsia/eclampsia
Maternal diabetes

Front 6

Where does Pregnancy occur. What happens after everything is expelled ?

Back 6

Functional layer

Basal layer renews after pregnancy

Front 7

Understand the sequnce of implantation

Back 7

The egg develops until ovulation, when it is fertilized the sperm. This then implants into the functional layer of the endometrium. The corpus luteum that is formed secretes E2 and progesterone maintaining the secretory endometrium.

Front 8

What happens the corpus luteum when there is no implantation ?

Back 8

When there is no fertilization, the CL degenerates and no HCG is produced. When it degrades, that is the menses phase (d1-4)

Front 9

Special endometrium of pregnancy ?

Back 9

Decidua

CHANGES IN SECRETORY GLANDS, STROMA, AND VESSELS OCCUR

STROMAL CELLS GAIN CYTOPLASM WHILE EPITHELIUM OF GLANDS LOSE CYTOPLASM (BECOMING FLAT)

Front 10

What is the functional of the maternal decidual formation and the vessels ?

Back 10

MOTHER’S DECIDUAL VASCULAR SPACE BECOMES THE “BATH” FOR EXCHANGE OF OXYGEN, NUTRIENTS, AND WASTE WITH THE FETAL CAPILLARIES

SPECIALIZED CHANGES IN MATERNAL DECIDUAL VESSELS CREATE THE “BATH”

Front 11

What change happens in the decidual vascular supply and what is their source ?

Back 11

The vessels remodel to provide low resistance to uterine blood flow. The vessels consist of 80-100 spiral arteries that are supplied by the myometrial arteries underneath

Front 12

When do fetal vessels develop, and what happens in the meanwhile ?

Back 12

These appear around 5-6 weeks of gestation. Usually before this the villi are avascular. If the fetal heart does not develop around 5 weeks, then the fetus will die

Front 13

What is a blighted ovum ?

Back 13

CAN HAVE POSITIVE hCG AND GESTATIONAL SAC WITHOUT HAVING A FETUS

PLACENTAL GROWTH DOES NOT REQUIRE FETUS, BUT DEVELOPMENT ARRESTS AT SECONDARY VILLUS STAGE IN THE ABSENCE OF A FETUS

SPONTANEOUS ABORTION RESULTS: THIS IS A “BLIGHTED OVUM”

Front 14

Why is it important to know if it was a blighted ovum ?

Back 14

Grief factor - patients might feel better if there was no fetus

Front 15

What is a secondary villus made of ?

Back 15

SCT and CT are seen, without any fetal vessels

It is no longer a solid column of primary villus. Secondary villus develops a loose mesenchymal core

Front 16

SCT

Back 16

Multinucleated giant cells

Front 17

What separates maternal and fetal blood ?

Back 17

FETAL CAPILLARY ENDOTHELIUM AND BASAL LAMINA
STROMA OF VILLUS (LOOSE)
BASAL LAMINA OF TROPHOBLAST
CYTOTROPHOBLAST
SYNCYTIOTROPHOBLAST
FIBRINOID (PATCHES HOLES IN THE SYNCYTIOTROPHOBLAST)

This is going from baby to maternal decidua.

Front 18

What exchange occurs at the tertiary villus ?

Back 18

Intake of Ig, nutrients and oxygen

and output of CO2

Front 19

Anchoring Villi

Back 19

Polar distribution of SCT occurs and they anchor to the decidua. The nearest maternal vessels proliferate and undergo fibrinoid chance creating a low resistance bath

Front 20

Tertiary villi

Back 20

DEMONSTRATE FETAL VASCULATURE

CYTOTROPHOBLAST IS LESS CONSPICUOUS

FARTHEST FROM THE CHORIONIC PLATE IS WHERE THE MOST EFFICIENT EXCHANGE OCCURS

FIBRINOID SHOULD BE SCANT IN THIS LOCATION

Why ?!?!?!?!?!?!?

Front 21

Placenta location and its layers

Back 21

The placenta is
commonly located in the upper half of the uterus. THE INNER LAYER OF
MEMBRANES IS THE AMNION, WHILE THE OUTER LAYER OF
MEMBRANES IS THE CHORION

Front 22

Understand the concept of the mothers blood not entering the fetus

Back 22

Basically the uterine arteries have enough low resistance to squirt blood through the floor of the intervillous spaces into the intervillous spaces. This blood trickles down across the villi to exit through venous channels and into the uterine vein. This way the exchange of gases occurs through the villi.

Clarify this with Dr. Hardt

Front 23

Pathology of eclampsia and preeclampsia in toxemic patients

Back 23

The "toxemic" patient's vessels are apparently damaged and unable to
dilate when necessary, and causing local ischemic decidual damage.

Front 24

Why does gas exchange not occur at the level of the proximal villi ?

Back 24

GAS EXCHANGE DOES NOT OCCUR AT THE LEVEL OF THE PROXIMAL OR STEM VILLI—LOTS OF FIBRINOID THERE

VILLI BRANCH, WITH DISTAL VILLI BEING THE FINEST AND BOASTING THE MOST VESSEL LOOPS FOR GAS EXCHANGE—IDEALLY LITTLE FIBRINOID, LITTLE STROMA

Front 25

What are the two major pathological changes in villi ? What is their effect ?

Back 25

Edema and Fibrosis

Both increase distance between Fetal and maternal RBCs impeding maternal gas exchange

Front 26

What do you know about the umbilical cord ?

Back 26

UMBILICAL CORD* IS VITAL CONDUIT FOR OXYGENATED BLOOD TO FETAL CIRCULATION

CORD VESSELS ARE SURROUNDED BY WHARTON’S JELLY

JELLY IS INSULATION, SERVING TO AVOID KINKING THE VESSELS

CORD LENGTH IS RELATED TO FETAL ACTIVITY
* normally: 2 arteries carrying unoxygenated blood & 1 vein

Front 27

When do all the villi appear by ? primary, secondary and tertiary ?

Back 27

1st trimester

Front 28

Number of pregnancy miscarriages in 1st trimester

percent of which have chromosomal abnormalities

What about the other remaining percentage ?

Back 28

20%

40% have chromosomal abnormalities

Remaining 60% have other genetic defects, endocrine problems, Abnormal vascular modeling etc

Front 29

What is the first clinical sign of a miscarriage ?

Back 29

1st trimester bleeding

Front 30

First trimester abortions. What percentage are anembryonic ?

Back 30

50%

Villi only develop into secondary villi and there is no embryo formation

Front 31

What is the clinical presentation of such a patient ?

Back 31

AFTER SOME WEEKS OF AMENORRHEA, THE PATIENT PRESENTS WITH BLEEDING

PHYSICAL EXAM REVEALS BLOOD IN THE VAGINAL VAULT

CERVICAL OS MAY BE OPEN OR CLOSED

Front 32

What are the uses of the US during pregnancy ?

Back 32

LOCALIZES THE CONCEPTUS

IS IT IN THE UTERUS?

IS THERE A HEARTBEAT?

IF THE ANSWER TO BOTH IS “YES”TREATMENT IS EXPECTANT

Front 33

For a first trimester abortion, what do you do if on ultrasound you find products of conceptus left behind?

Back 33

Curettage or methotrexate.

If you dont see anything, then observe complete

Front 34

What can you tell by the blood loss during a pregnancy ?

Back 34

USUALLY MINIMAL FOR INTRAUTERINE PREGNANCY WITH SPONTANEOUS ABORTION

IF CONCEPTUS IS IN EXTRAUTERINE SITE*, BLEEDING CAN BE CONSIDERABLE
* ectopic pregnancy: risk of maternal exsanguination

Front 35

What percent of spontaneous abortions have a normal karyotype ?

What percent have abnormalities in chromosomes ?What are the common abnormalities ?

Back 35

Over 50%

40%. the most common abnormalities are trisomies, turner syndrome and triploidy

Front 36

What percent of new borns have a major chromosomal abnormality ?

Back 36

0.5% and the most common is Down syndrome and a sex chromosomal abnormality in a make (XXY and XYY)

Front 37

What is a livebirth or stillbirth

Back 37

delivery at 20 wks or later is either a livebirth or a stillbirth

Front 38

What are the causes of a Thrid trimester bleeding ?

Back 38

NO LONGER CALLED “THREATENED ABORTION”*

MAY BE DUE TO
PREMATURE LABOR,
ABRUPTIO PLACENTA, PLACENTA PREVIA,
FETAL DEATH IN UTERO (STILLBORN)

Front 39

Abruptio Placenta

Back 39

PREMATURE SEPARATION OF PLACENTA FROM ENDOMETRIUM

Front 40

Placenta Previa

Back 40

PLACENTA IMPLANTATION OVER CERVICAL OS, AS LOWER UTERINE SEGMENT THINS, THE PLACENTA SEPARA

Front 41

What happens to the placenta when the baby is delivered ?

Back 41

Placenta usually stays in the body longer than the baby and is expelled by the mother later on

Front 42

Know this

Back 42

HISTOLOGIC CHANGES TAKE HOURS TO DEVELOP, THEREFORE ANYTHING OBSERVED GENERALLY PRECEDES LABOR

Front 43

What are the causes of placental malfunction ?

Back 43

MATERNAL UNDERPERFUSION
INTERFERENCE WITH DIFFUSION ACROSS MATERNAL/ FETAL INTERFACE
THROMBI IN LARGE FETAL VESSELS
OBSTRUCTED UMBILICAL VEIN
MATERNAL ILLNESS (DIABETES, BP)

Front 44

PLACENTA FROM SEVERE TOXEMIA

Back 44

The multiple infarcts in this
placenta are due to thrombosis in the maternal arteries and venous sinuses within the decidua.

Preeclampsia - Fibrotic villi w/o gas exchange

Front 45

ERYTHROBLASTOSIS FETALIS - PLACENTA

Back 45

This placenta is abnormally pale.It weighed more than 900 grams and was far heavier than expected due to the edema of the villi.