Pregnancy and childbirth

Question 1

What hormones is pregnancy maintained by?

Answer 1

-hCG
-oestrogens
-progesterones

Question 2

Where is hCG produced and what does it cause in pregnancy?

Answer 2

produced in the placenta and causes nausea and vomiting in early pregnancy

Question 3

What does the hormone relaxin do?

Answer 3

increases flexibility of the pubic symphysis and helps dilate the uterine cervix near the end of pregnancy

Question 4

What does the Human Placental Lactogen (hPL) hormone do?

Answer 4

contributes to breast development protein anabolism and catabolism of glucose and fatty acids

Question 5

What does the Corticotropin-releasing hormone (CRH) do and where is it produced?

Answer 5

produced by the placenta, and establishes the timing of birth, and stimulates the secretion of cortisol by the fatal adrenal gland

Question 6

How does the heart change during pregnancy?

Answer 6

-increases in size and volume to accommodate additional blood volume
-CO increases
-displaced upwards and forwards
-reversible ECG change
-increased HR and palpitations

Question 7

How does the blood and vessels change during pregnancy?

Answer 7

-lower diastolic pressure in 2nd trimester= fainting
-relaxation of vessels
-increased blood volume
-non-specific immunity increases, cell mediated immunity decreases

Question 8

How does the skin change during pregnancy?

Answer 8

-oestrogen and progesterone increase production of melanocyte, increasing skin pigmentation
-stretching of skin= striae gravidarum stretch marks

Question 9

How does the musculoskeletal system change during pregnancy?

Answer 9

-relaxin and progesterone softening of joints and ligaments= risk of falls
-altered sense of gravity
-altered calcium metabolism cause slow calcium causing leg cramps

Question 10

How does the GI tract change during pregnancy?

Answer 10

-nausea and vomiting
-increased gum disease and bleeding
-hormones relax and smooth muscles

Question 11

What renal changes occur during pregnancy?

Answer 11

-GFR increases to accommodate fluid volume
-kidneys enlarge
-increased risk of UTI

Question 12

What is amniocentesis prenatal diagnostic test and how is it carried out and when?

Answer 12

-involves removing some amniotic fluid surrounding the developing fetus and analysing it and fatal cells for genetic abnormalities
-usually around 14-18 weeks
-needle used to collect the fluid is guided by ultrasound to avoid damage to the fetes or umbilical cord

Question 13

What is a teratogen and give some examples?

Answer 13

-any agent or influence that can cause developmental defects in an embryo or foetus
-e.g chemicals, drugs, alcohols, viruses, hormones, antibiotics

Question 14

When is true labour classes as starting?

Answer 14

when uterine contractions are at regular intervals

Question 15

What are the 3 stages of true labour?

Answer 15

1. stages of dilation
2. stage of expulsion
3. placental stage

Question 16

What is the uterus?

Answer 16

-pear shaped organ with 3 layers, the middle one being the myometrium which consists of 3 muscle layers that can stretch and contract, which then leads to expulsion of the foetus and placenta

Question 17

What happens in stage 1, dilation, of labour?

Answer 17

-baby moves deeper into birth canal
-pressoreceptors in cervix of uterus excited
-afferent impulses to hypothalamus
-hypothalamus sens impulses to posterior pituitary to release oxytocin into blood, targeting the mothers uterine muscle
-uterus responds by contracting more vigorously

-this is a positive feedback mechanism until it is interrupted by birth of baby

Question 18

What happens in stage 3, expulsion of placenta, of labour?

Answer 18

-the most hazardous time for the mother due to risk of haemorrhage (heavy bleeding)
-post partum haemorrhage is defined as blood loss in excess of 500ml

Question 19

What respiratory changes does the newborn baby undergo?

Answer 19

-transition to breathing air
-surfactant production begins around 24 weeks gestation, which at birth allows the lungs to easily inflate and exchange O2 and CO2

Question 20

What cardiovascular changes does the newborn baby undergo?

Answer 20

-O2 blood from placenta enters R atrium via vena cava
-foramen vale allows O2 blood in R atrium to reach L atrium
-ductus arterioles connects the aorta with pulmonary artery, shunting blood away from lungs and into aorta
-mixed blood travels to the head and body and back to the placenta via aorta

Question 21

How do newborn babies thermoregulate and why is this important?

Answer 21

-have specialised brown adipose tissue to produce heat via mitochondrial reaction
-this is stimulated by cold exposure and sympathetic nervous system

Question 22

What is lactation?

Answer 22

The production and ejection of milk from the mammary glands

Question 23

What hormones play a role in lactation?

Answer 23

-prolactin is the main hormone in stimulating milk production
-oxytocin causes release of milk into mammary ducts via milk ejection reflex

Question 24

Why is it important babies receive breast milk?

Answer 24

contains immune factors and change in response to the infants needs

Question 25

What is colostrum?

Answer 25

fluid rich in fats and proteins secreted from the breast before true breast milk