Pregnancy

Question 1

Recall the time limits at which a baby is known as a zygote, blastocyst, embryo and foetus

Answer 1

Zygote - fertilisation to day 5
Blastocyst = days 5-9
Embryo = first 8 weeks
Foetus = thereafter

Question 2

What does “conceptus” refer to?

Answer 2

Everything resulting from fertilised egg:
Baby
Placenta
Foetal membranes
Umbilical cord

Question 3

In the UK, what is the gestational age at which an attempt at revival must be made if they are born pre-term?

Answer 3

24 weeks

Question 4

In which trimester does the neural tube close?

Answer 4

1st

Question 5

In the absence of an ICU cot, what is the absolute limit of gestational period for survival of a pre-term baby?

Answer 5

27 weeks

Question 6

With an ICU cot, what is the absolute limit of gestational period for survival of a pre-term baby?

Answer 6

23 weeks

Question 7

How many days since LMP is considered to be “term”?

Answer 7

280

Question 8

Which gestational weeks are considered “term”?

Answer 8

37-41

Question 9

Summarise the hormonal changes during the first trimester

Answer 9

hCG peaks

O,P and placental lactogen begin to increase

Question 10

Why do O, P and PL levels continue to rise thorughout pregnancy?

Answer 10

Produced by placenta, which increases in size

Question 11

Describe the levels of LH and FSH throughout pregnancy

Answer 11

Very low as high levels of O and P suppress the HPG axis

Question 12

What is the proper name given to morning sickness?

Answer 12

Hyperemesis gravidarum

Question 13

Recall the probably cause of hyperemesis gravidarum

Answer 13

hCG

Question 14

Recall 2 possible mechanisms for the altered immune response in pregnancy

Answer 14

1. Endogenous immunosuppressant production at utero-placental interface
2. HLA-G expression

Question 15

In which trimester is there a change in blood pressure, and in which direction does it change?

Answer 15

2nd

Drops significantly

Question 16

Recall the 2 major maternal changes in the 3rd trimester

Answer 16

1. Loosening of pelvic joints

2. Weight gain of 10-15kg

Question 17

Recall the source of progesterone throughout pregnancy

Answer 17

Initially corpus luteum - hCG drives production

Lutoplacenteal shift at 8 weeks

Question 18

Recall the source of oestrogen throughout pregnancy

Answer 18

First 8 weeks: corpus luteum

Following LPS: foetal andrenals produce DHEA, placenta converts to 17-B-oestradiol, liver converts to oestrone

Question 19

Why is DHEA not produced in the placenta?

Answer 19

Does not express the required isoform of CYP450

Question 20

To where does the placenta anchor in the uterus?

Answer 20

Decidua

Question 21

What is the approximate surface area of the placenta?

Answer 21

11 m^2

Question 22

How many days post-fertilisation does the blastocyst implant?

Answer 22

9

Question 23

What is the outer later of the conceptus composed of?

Answer 23

Multinucleated synctiotrophoblasts

Question 24

In which cells of the conceptus does the placenta develop?

Answer 24

Cytotrophoblasts

Question 25

Describe the development of the placental blood supply during pregnancy

Answer 25

1. Branches into villous sprouts
2. Isolated from maternal blood supply by 4 weeks
3. At 8 weeks: cytotrophoplast plug breakdown; spiral artery formation
4. During 2nd and 3rd trimesters there is increased branching, placental diameter = 5–> 20cm

Question 26

What is the gestational age limit for a foetal death to be considered “miscarriage”?

Answer 26

23 weeks

Question 27

What is the most common cause of miscarriage?

Answer 27

incomplete anchrage of placenta

Question 28

How is still birth risk assessed?

Answer 28

Foetal movement on ultrasound