Ovarian and Fetal Imaging

Question 1

What is obstetric dating taken from?

Answer 1

The LMP, so ovulation and conception 2-3 weeks after

Question 2

What two ways of imaging are there for pregnancy/uterus?

Answer 2

Transabdominal: Sees bladder above.
Transvaginal: Probe through vagina, see uterus, cervix etc. Closest and best image

Question 3

What is the CRL and what can we obtain from it?

_mm 6 weeks (note embryo visible);
_mm 7 weeks;
\_\_mm 8 weeks; 
\_\_mm 9 weeks
Important to monitor growth, abnormal is from week 6-7 no \_\_\_\_ in length

Answer 3

Crown rump length.
4mm 6 weeks (note embryo visible);
8mm 7 weeks;
15mm 8 weeks; 
22mm 9 weeks
Important to monitor growth, abnormal is from week 6-7 no doubling in length

Question 4

What defines a threatened abortion (note first tri 25% chance failure)

Answer 4

Bleeding and cramping in first 20 weeks

Question 5

What would constitute abnormal gestation sac?

Answer 5

No yolk sac; no double decidual reaction; no embryo (empty sac)

Question 6

Important first trimester findings for failure

Answer 6

• CRL > 7mm with no fetal heartbeat
• Mean sac diameter >25mm with no embryo (note still feels pregnant)
• Absence of embryo 2 weeks post US that showed no yolk sac

Question 7

Are threatened miscarriages normal? How can the appear?

Answer 7

Are abnormal in first tri, but is very common.

Is often a subchorionic bleed

Question 8

What is an anembryonic pregnancy?

Answer 8

A gestational sac without an embryo

empty sac; blighted ovum; afetal sac

Question 9

Ectopics

Answer 9

90% FTs
10% bowel, ovary, pelvis
IVF at higher risk

Question 10

What is indication of ectopics?

Answer 10

Pouch of Douglas fluid (NOTE also get fluid in here at ovulation, so negative pregnancy test)

Question 11

How do you terminate a pregnancy?

Answer 11

Methotrexate: kills dividing cells

Question 12

Corpus luteum, when does it regress?

Answer 12

Cysts are often seen, stop functioning at 10-12 weeks

Question 13

Gestational trophoblastic disease

Answer 13

Trophoblast proliferation like hayditiform moles, choriocarcinoma. Look at bhCG levels

Question 14

How does b hCG change during pregnancy

Answer 14

Secreted by trophoblasts
In weeks 4-8, doubles every 2-3 days
Levels will vary in different people

Question 15

How do dates (EDD) vary with time?

Answer 15

1st tri: can estimate +- 5 days
2nd tri: +- 10 days
3rd tri: +- 3 weeks

Be consistent with due date, do not change