Pregnancy and childbirth Flashcards
What hormones is pregnancy maintained by?
-hCG
-oestrogens
-progesterones
Where is hCG produced and what does it cause in pregnancy?
produced in the placenta and causes nausea and vomiting in early pregnancy
What does the hormone relaxin do?
increases flexibility of the pubic symphysis and helps dilate the uterine cervix near the end of pregnancy
What does the Human Placental Lactogen (hPL) hormone do?
contributes to breast development protein anabolism and catabolism of glucose and fatty acids
What does the Corticotropin-releasing hormone (CRH) do and where is it produced?
produced by the placenta, and establishes the timing of birth, and stimulates the secretion of cortisol by the fatal adrenal gland
How does the heart change during pregnancy?
-increases in size and volume to accommodate additional blood volume
-CO increases
-displaced upwards and forwards
-reversible ECG change
-increased HR and palpitations
How does the blood and vessels change during pregnancy?
-lower diastolic pressure in 2nd trimester= fainting
-relaxation of vessels
-increased blood volume
-non-specific immunity increases, cell mediated immunity decreases
How does the skin change during pregnancy?
-oestrogen and progesterone increase production of melanocyte, increasing skin pigmentation
-stretching of skin= striae gravidarum stretch marks
How does the musculoskeletal system change during pregnancy?
-relaxin and progesterone softening of joints and ligaments= risk of falls
-altered sense of gravity
-altered calcium metabolism cause slow calcium causing leg cramps
How does the GI tract change during pregnancy?
-nausea and vomiting
-increased gum disease and bleeding
-hormones relax and smooth muscles
What renal changes occur during pregnancy?
-GFR increases to accommodate fluid volume
-kidneys enlarge
-increased risk of UTI
What is amniocentesis prenatal diagnostic test and how is it carried out and when?
-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
What is a teratogen and give some examples?
-any agent or influence that can cause developmental defects in an embryo or foetus
-e.g chemicals, drugs, alcohols, viruses, hormones, antibiotics
When is true labour classes as starting?
when uterine contractions are at regular intervals
What are the 3 stages of true labour?
- stages of dilation
- stage of expulsion
- placental stage
What is the uterus?
-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
What happens in stage 1, dilation, of labour?
-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
What happens in stage 3, expulsion of placenta, of labour?
-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
What respiratory changes does the newborn baby undergo?
-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
What cardiovascular changes does the newborn baby undergo?
-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
How do newborn babies thermoregulate and why is this important?
-have specialised brown adipose tissue to produce heat via mitochondrial reaction
-this is stimulated by cold exposure and sympathetic nervous system
What is lactation?
The production and ejection of milk from the mammary glands
What hormones play a role in lactation?
-prolactin is the main hormone in stimulating milk production
-oxytocin causes release of milk into mammary ducts via milk ejection reflex
Why is it important babies receive breast milk?
contains immune factors and change in response to the infants needs
What is colostrum?
fluid rich in fats and proteins secreted from the breast before true breast milk
