Pregnancy

Question 1

From when can maternal blood reach placenta?

Answer 1

After 10-12 weeks

Question 2

How many vessels are there in the umbilical cord?

Answer 2

1 vein carrying blood and oxygen to the baby

2 arteries carrying waste products to the placenta

Question 3

What prevents maternal blood flow to the placenta?

Answer 3

Endovascular trophoblast

In 2nd trimester, this plug had disappeared and blood can flow freely

Question 4

What is histiotrophic nutrition?

Answer 4

Nutrition provided to the baby from the endometrium and uterine gland

Question 5

What is haemotrophic nutrition?

Answer 5

Nutrition provided to the baby from the maternal blood flow

Question 6

What is the syncytiotrophoblast?

Answer 6

is the epithelial covering of the highly vascular embryonic placental villi, which invades the wall of the uterus to establish nutrient circulation between the embryo and the mother

Question 7

Describe the blood transport from mother to baby (4 vessels)

Answer 7

Maternal uterine artery
Fetal umbilical vein
Fetal umbilical artery
Maternal uterine vein

Question 8

How is fetal HCO3- excreted?

Answer 8

HCO3- is converted into carbonic anhydrase into CO2, which follows concentration gradient and is expired by mother

Question 9

When is the gut fully developed?

Answer 9

Week 19

Question 10

What is macrosomia?

Answer 10

Overweight at birth

Question 11

What are the complications related to macrosomia?

Answer 11

Causes labour difficulties
Associated with increased obesity
Increased risk of stillbirth
Often C section, as brachial plexus can get damaged

Question 12

How much fluid do fetal kidneys produce?

Answer 12

500-700mL, becomes part of amniotic fluid

Question 13

What is the fetal heart rate determined by?

Answer 13

Catecholamines and chemoreceptors

Parasympathetic tone

Question 14

What is the ductus venosus?

Answer 14

shunts a portion of umbilical vein blood flow directly to the inferior vena cava

Question 15

What is the foramen ovale?

Answer 15

is a normal opening between the upper two chambers (the right atrium and left atrium) of an unborn baby’s heart. The foramen ovale usually closes 6 months to a year after the baby’s birth.

Question 16

What is the ductus arteriolus?

Answer 16

is a normal blood vessel that connects two major arteries — the aorta and the pulmonary artery — that carry blood away from the heart

Question 17

How does the foramen ovale close?

Answer 17

Cord occlusion changes arterial pressure and presses the foramen ovale shut

Question 18

What are the two types of alveolar cells?

Answer 18

Type I allow for gas exchange

Type II produce surfactant (larger cells, stabilise lungs, decrease surface tension)

Question 19

What is the relationship between surfactant and prematurity

Answer 19

Less production of surfactant, leading to difficulty breathing

Question 20

what is the treatment for inadequate surfactant?

Answer 20

Exogenous surfactant

Give mother steroids so lungs develop faster

Question 21

What are the two parts of a blastocyst?

Answer 21

1. Trophoblast (outer)

2. Embrryoblast (inner)

Question 22

What is the acrosome reaction?

Answer 22

Zona protein 3 (ZP3) on the egg binds with the sperm

This initiates the acrosome reaction, exposing hyaluronidase and acrosin in the acrosome to the egg.

This activates the oocyte, causing cortical granules to be released , preventing polyspermic penetration.

Meiosis resumes

Question 23

What is linea nigra?

Answer 23

Often referred to as a pregnancy line, is a linear hyperpigmentation that commonly appears on the abdomen

Often seen in first trimester

Question 24

What causes linea nigra?

Answer 24

MSH production by the placenta

Question 25

If there are concerns about the fetus' growth, what investigations do you do?

Answer 25

Amniotic fluid index (normal range 5-25 cm) and uterine artery doppler

Question 26

When is the first ultrasound offered to all pregnant women?

Answer 26

12 weeks

Question 27

When is the second ultrasound done in pregnancy?

Answer 27

18-20 weeks

Question 28

What is measured during the second ultrasound in pregnancy?

Answer 28

``` Here the fetus is checked for abnormalities and there is an assessment of fetal growth, it includes four measurements: Head circumference Bi-parietal diameter Abdominal circumference Femur length ```

Question 29

During what developmental phase is the embryo at greatest risk of morphological abnormalities?

Answer 29

Embryonic phase

Question 30

During what developmental phase is the embryo at greatest risk of functional abnormalities?

Answer 30

Fetal phase

Question 31

How do HR, CO, BP, aldosterone, angiotensin II and renin change during pregnancy?

Answer 31

``` Heart rate = increases Cardiac output = increases Blood pressure = decreases Aldosterone = increases Angiotensin II = increases Renin = increases ```

Question 32

When are chromosomal screening tests offered?

Answer 32

Who - all women When - first trimester scan How - USS fetal nuchael translucency and blood test (HCG, PAAP-A) If positive - counselling, termination

Question 33

What is circulating testosterone bound to?

Answer 33

Sex hormone binding globulin

Question 34

How do clotting factors and plasma fibrinogen levels change in pregnancy?

Answer 34

Clotting factors VII, VIII, X = increases Plasma fibrinogen = increases Fibrinolytic activity = decreases

Question 35

What is the result of maternal rubella infection during the first 20 weeks of pregnancy?

Answer 35

Eyes - Congenital cataracts, pigmentary retinopathy Heart - Patent ductus arteriosus Neurological - Microcephaly, developmental delay ENT - Hearing impairment

Question 36

What hormones do FSH and LH stimulate?

Answer 36

Inhibin and oestrogen

Question 37

What do Inhibin and oestrogen do in females?

Answer 37

Oestrogen regulates the menstrual cycle whereas inhibin inhibits activin. Increasing oestrogen and inhibin have a inhibitory effect on the pituitary and hypothalamus, leading to decreased production of LH, FSH and GnRH.

Question 38

What does LH do in men?

Answer 38

LH is released from the anterior pituitary, stimulating Leydig cells to produce testosterone.

Question 39

Who do testosterone and FSH do?

Answer 39

Testosterone and FSH stimulate the Sertoli cells, facilitating spermatogenesis and development of secondary sex characteristics. Sertoli cells also release inhibin.