Clinical: Imaging in Reproduction

Question 1

What week does implantation occur?

Answer 1

Week 3 (since LMP)

Question 2

When does the gestation sac develop?

Answer 2

Week 4 (since LMP)

Question 3

When does the gestation sac + yolk sac develop?

Answer 3

Week 5 (since LMP)

Question 4

When does the gestation sac + yolk sac + embryo develop?

Answer 4

Week 6-7 (since LMP)

Question 5

When is it an “embryo” and when is it a “Fetus”?

Answer 5

6-10 11-40

Question 6

What is the thing the arrow is pointing at an what is the whiter stuff around it?

Answer 6

Arrow= Gestational sac

White = trophoblast

Question 7

Why is the 1 side longer than the other?

Answer 7

One side- Placenta

Question 8

Describe Growth (CRL)

Answer 8

4mm- 6 weeks

8mm- 7 weeks

15mm- 8 weeks

22mm - 9 weeks

(start to slow down between week 8 and week 9)

In all conditions, the growth must double every week. If it’s not growing, it is a failed pregnancy.

Question 9

Failure during _______trimester is common

Answer 9

First trimester

Question 10

What is a threatned abortion/miscarriage?

Answer 10

Defined as bleeding and cramping in the first 20 weeks of

Bleeding in the first tremester very common, although no normal

Sub Chorionic bleed

25-30% of first trimester pregnancy have some PV bleeding

(If it occurs away from the side of the embryo in the gestational sac, we can be relatively reassured. If the subchorionic bleed occurs at the side of the embryo, it can lead to fetal demise as it’s affecting the blood supply of the embryo)

Question 11

What is an abnormal gestation sac?

Answer 11

• A true gestational sac can be distinguished from a pseudogestational sac by noting:
  
  • its normal eccentric location: it is embedded in endometrium, rather than centrally within the uterine cavity
  • presence of the double decidual sign (most helpful at 4.0-6.5 weeks)
  • presence of a yolk sac: seen at approximately 5.5 weeks (unequivocal evidence of a gestational sac)

Abnormal:

Lac of yolk sac

Lack of double decidual reaction (lack of trophoblast)

Lack of embryo

Question 12

What do you see on imaging when there is absent cardiac acitivty by the time the CRL is a certain size

Answer 12

CRL > 7 mm with no heart beat

(CRL= crown rub length- top to bottom)

Question 13

What do you see if there is an absent embryo by the time the gestational sac is a certain size

Answer 13

MSD > 25mm with no embryo (mean sac dimester across 3 dimestions of gestation sac)

Question 14

What is CRL?

Answer 14

From top to bottom length measurement

Question 15

If you cannot see an embryo at 10 weeks, how can someone have pregnancy symtpoms?

Answer 15

Trophoblast

Question 16

What are some high risk examples?

Answer 16

1) Low (near cervix)
2) Irregular trophoblast
3) If Sac is too small

Question 17

What does a 8mm yolk sac suggest?

Answer 17

Not good- likely to fail

Question 18

What HR should an early embryo have?

Answer 18

120-140bpm

Question 19

When the gestation sac grows but the embryo doesn’t is called….

Answer 19

Anembryonic pregnancy

(Empty sac, afetal sac, blighted ovum)

Question 20

Any fetuses over 7mm must have….

Answer 20

A heart beat.

(must check with colour, doppler, and another observer)

Question 21

What are 2 common abnormal implantations

Answer 21

1) Fetal demise
2) Ectopic Pregnancy

Question 22

Describe Ectopic Pregnancy

Answer 22

An ectopic pregnancy occurs when an embryo implants somewhere other than the uterus

~90% fallopian tube, ~10% ovary/pelvis/bowel

1/80 to 1/250 pregnancies increase in pelvic inflammatory disease

1) Gestational sac in pouch of douglas/behind the fallopian tube
2) Fluid in pouch of douglas

Question 23

23 year old woman, bleeding in flank, in shock

what is this likely to be?

Answer 23

Ectopic pregnancy

Question 24

What is a normal reasons for fluid in the pouch of douglas?

What is an abnormal reason?

Answer 24

Small normal reason: Menstruation and Ovulation

Abnormal reason: Ectopic

Question 25

Describe gestational trophoblastic disease

Answer 25

= Molar Pregnancy

Is the trophoblast going bad/malignant?

They can proliferate (some are bengin and some ar malignant).

They have extreme morning sickness, and very very high BHCG

In the early week 4-8, BHCG doubles every 2-3 days.

Question 26

Empty uterus, 5000units of BHCG indicates….. **EXAM

Answer 26

ECTOPIC PREGNANCY

Question 27

When are ultrasound scans very helpful?

Answer 27

1) Dating (Estimated date of delivery- EDD)
- Accuracy diminishes with each trimester
- Go with the first trimester scan- don’t let people change it.
2) Twelve week nunchal translucency scan (for genosomal abnormalies e.g. trisomy 21)

3) Routine anatomy scan 20 weeks

4) Growth scan 3rd trimester

Question 28

Do we need to know the serum BHCG value before we perform the ultrasound scan?

Answer 28

If you are scanning someone with good dates, you can just start scanning and you don’t need BHCG

If things don’t add up, you need the BHCG to interpret what you’re looking at. you want them to come in again in 2-3 days to see what’s going on.

Question 29

The patient’s LMP was only 3 weeks ago. Why should we do an ultrasound scan when an ectopic pregnancy does not manifest until 5 weeks after the LMP?

Answer 29

Need a BHCG (to get a clear idea of what we expect to see)

-e.g. if it’s negative = no pregnancy

Need to scan her

The bleeding does not always indicate it was a normal period (we can even have periods once pregnant)

Question 30

I am pregnant, by my dates- 6 weeks and 5 days. I turned up for my scan today and was told that they could not see the baby. They asked me to return for another scan in another week. What does this mean? I am very worried.

Answer 30

We’d ask her to do a BHCG test and come back in a week to clarify whether we are dealing with an early intrauterine preg

Question 31

My wife is 9 weeks preg. She has had an on and off bleeding and spotting for the past 3 weeks. She has already had 3 ultrasound scans- always showing a strong heartbeat.

The doctor does not seem very worried. What is causing her bleeding Should we be worried?

Answer 31

Subchorionic bleed?

Question 32

I had a scan when I was 8 weeks pregnant by dates.

The scan said the fetus was 7.5 weeks because of my irregulat menstrual cycle. I have just had naother scan at 34 weeks and my doc says the fetus is the size of a 31 weeks baby.

Should I change my due date?

Answer 32

No do not change the due date (1st trimester estimated due date is a lot more accurate)

Question 33

Woman has had terrible mroning sickness,vomitting continuously, uable to eat, etc.

The scan shows an “empty scan” measuring 40mm

Answer 33

Failed pregnancy

Sickness is due to the trophoblasts

Question 34

My girlfriend had a 12 week scan and a 20 week scan and was told everything was fine.

Now she has had our baby and there is a hole in the heart.

How could they have missed this?

Answer 34

Foramen ovale

The fetal circulation has not closed compeltely - this could not have been picked up in the scans