Maternal Changes In Pregnancy Flashcards
What are the reasons for changes in pregnancy?
β High levels of fetal steroids
β Mechanical displacement
β Fetal requirements
What kind of an event is pregnancy?
β Physiological
What can pregnancy do physiologically to existing conditions?
β Exacerbate an existing condition
β uncover a hidden or mild condition
What are 6 changes that occur during pregnancy?
β Increase in uterus size
β Increase metabolic requirements of the fetus
β Structural and metabolic requirements of the fetus
β Removal of fetal waste products
β Prevision of amniotic fluids
β preparation for delivery and puerperium
In what systems do pregnancy changes occur?
β Respiratory system β Cardiovascular system β GI β Urinary β Endocrine
What are the three placental peptides?
β hCG, hPL, GH
What takes over progesterone production?
β Corpus luteum
What is the corpus luteum kept alive by?
β hCG
What are the placental and fetal steroids?
β Progesterones
β Estradiol
β Estrogen
What 4 hormones induce insulin resistance?
β Growth hormone
β Corticotropin releasing hormone
β Estrogen
β Human placental lactogen
Why do you want the myometrium to be quiescent?
β Contractions would cause miscarriage
What is the total weight gain during pregnancy?
β 12.5 - 13kg
What is the breakdown of the weight gain during pregnancy?
β Fetus + placenta - 5kg β Fat and protein - 4.5kg β Body water 1.5kg β Breasts - 1kg β Uterus 0.5-1kg
Where is fat mainly laid down?
β Anterior abdominal wall
What does the basal metabolic rate rise by in mid and late gestation?
β 350kcal/day - mid
β 250kcal/day - late
How does glucose get to the fetus?
β Facilitated diffusion across the placenta
Where does the fetus store glucose?
β in the liver
Describe what happens to maternal glucose reserves in the first trimester
β Pancreatic Γ cells increase in number
β plasma insulin increases
β Fasting serum glucose decreases (laid down as stores and used by muscle)
Describe what happens to fetal glucose reserves in the second trimester
β hPL causes insulin resistance
β less glucose into stores
β increases availability in serum glucose so more crosses the placenta
Describe how gestational diabetes occurs?
β Hormones antagonise the effects of insulin
β Insulin increases
β Beta cells become hypertrophied
β Glucose is going into cells to be stored
β insulin resistance gets higher due to hPL
β The body makes more insulin to overcome the resistance
β if you are already obese and insulin resistant you get gestational diabetes
Describe how water gain occurs in pregnancy
β Estrogen and progesterone activate the RAAS system
β Sodium is retained
β Plasma volume increases by 40-50%
β A litre of amniotic fluid is made
Why do you breathe quicker and deeper during pregnancy?
β Estrogen and progesterone increase respiratory sensitivity to CO2
What does the minute volume increase by?
β 40%
What is gas transfer like between mother and fetus
β high O2 in mothers blood it favors transfer to the fetus
β high CO2 in fetus it goes to the mother
What does the plasma volume increase by?
β 40-50%
How does Hb concentration change in pregnant women?
β it decreases
β Red cell count goes up by 20% but the plasma goes up by 40% so the Hb is more diluted
How is more iron absorbed?
β Transferrin
Why do you become hypercoagulable?
β clotting factors increase
What does smoking do to fetal blood?
β Increases maternal carboxy-Hb which reduces binding of O2
β fetal hypoxia
How is blood transferred from the mother to the fetus?
β Fetal blood has increased Hb
β Increased O2 binding
β Oxygen is given up by maternal Hb
How much does cardiac output increase by?
β 40-50%
What is preeclampsia?
β High blood pressure
What is blood pressure like during pregnancy and why?
β Blood pressure = peripheral resistance x CO
β if CO goes up by 40-50% the blood pressure must go down
β peripheral resistance must decrease
β HIGH VOLUME AND LOW PRESSURE
Where does blood flow increase?
β Uterus
β Placenta
β Muscle
β Kidney and skin
Why does neoangiogenesis occur?
β Extra capillaries in skin to assist with heat loss
How does acid reflux occur?
β in the third trimester the LOS tends to relax
What does progesterone do to the GI tract?
β Increases appetite
β Smooth muscle relaxation throughout the whole gut
β a common side effect is constipation
What does deficiency of folic acid lead to?
β Spina bifida - neural tube defect
How much folic acid should be taken?
β 5mg/day upto week 12
Why do pregnant women get UTIs?
β If you ultrasound a pregnant womanβs kidneys they are dilated
β You may not void everything and get static urine and get UTIs
How much does the filtrate increase by and why?
β 40-50% because all the cardiac output goes through the kidney as well
Why is there increased frequency in urination during pregnancy?
β Babyβs head is pressing on the bladder in very late pregnancy
What does the uterus hypertrophy in response to?
β Estrogen
Where is the incision for a C section done?
β Just above the symphysis
When does the cervix tissue soften?
β From 8 weeks
What is the function of the cervix?
β To retain the pregnancy
What happens to the glands in the cervix?
β Great increase in mucus production
β Anti-infective
What happens when the placenta is delivered?
β Rapid fall in steroids
What happens to the uterus after delivery?
β Rapidly loses oedema but contracts slowly
β Never returns to pre-pregnancy size
What enables prolactin?
β Removal of steroids
