Maternal Problems in Pregnancy Flashcards
What do we look for in antenatal screening of the mother?
History & Examination – Risk factors – e.g. for gestational diabetes. Blood tests: blood group, Haemoglobin (pregnant women tend to be anaemic), Infection and Urinalysis for Proteins (sign of pre eclampsia).
What changes occur in the heart during pregnancy?
Many haemodynamic changes occur, blood volume increase, remember the relationship between cardiac output and stroke volume and heart rate, Cardiac output, stroke volume and HR all increase.
What changes occur in blood pressure?
Systolic BP is never increased in pregnancy (normally). Hypotension – T1 & T2 – progesterone effects on SVR (systemic vascular resistance) thus BP usually drops at the beginning of pregnancy then slowly increases through these first two terms. T3 increased blood volume causes return back to normal unless aortocaval compression by gravid uterus causing hypotension due to reduced venous return.
What happen in pre-eclampsia?
Pre-eclampsia / Eclampsia – high BP and protein in the urine
Normal pregnancy – vasodilated, plasma-expanded
Pre-eclamptic pregnancy – vasoconstricted, plasma-reduced.
Pathophysiology: defect in placentation, poor uteroplacental circulation, widespread endothelial dysfunction.
What changes occur in the urinary system and what consequences does this have?
Glomerular filtration rate increases, renal plasma flow increases, filtration capacity intact, functional renal reserve decreases as GFR increases.
Consequences
Urinary stasis – Progesterone effect on urinary collecting system, hydroureter – Obstruction. UTIs – Pyelonephritis resulting in Pre-term labour.
What changes occur in the respiratory system and what consequences does this have?
Anatomical changes – Diaphragm displaced – A-P and transverse diameters of thorax increase. Physiological changes
Consequences - decreased functional residual capacity, vital capacity unchanged, total lung capacity unchanged, Increased minute & alveolar ventilation, Increased tidal volume and RR unchanged.
What general affect do all these changes in the resp system incur on the pregnant body?
Physiological hyperventilation – Increased metabolic CO2 production – Increased respiratory drive effect of progesterone – Resulting in respiratory alkalosis, compensated by increased renal bicarbonate excretion. “Physiological” dyspnoea – Due to progesterone-driven hyperventilation
How does the maternal metabolism of carbohydrates change in pregnancy?
Placental transport of glucose – facilitated diffusion. Pregnancy increases maternal peripheral insulin resistance – Switches to gluconeogenesis and alternative fuels. Achieved by: – human placental lactogen also, prolactin, oestrogen / progesterone, cortisol.
Blood glucose in pregnancy
Decrease in fasting blood glucose and an increase in post-prandial blood glucose.
What is gestational diabetes?
Carbohydrate intolerance first recognised in pregnancy and not persisting after delivery
Risks associated with poor control – Macrosomic foetus – Still birth – Increased rate of congenital defects. Oral glucose tolerance test required.
How does lipid metabolism change in pregnancy?
Increase in lipolysis from T2. Increase in plasma free fatty acids on fasting. Free fatty acids provide substrate for maternal metabolism, leaving glucose for foetus.
What changes occur in thyroid function in pregnancy?
Thyroid binding globulin production increase. T3 and T4 increased, Free T4 in normal range, hCG direct effect on thyroid stimulating thyroid hormone production – TSH can be decreased in normal pregnancies.
What anatomical difference is there in the GI tract in pregnancy?
Alterations in the disposition of the viscera – e.g. Appendix moves to RUQ as uterus enlarges Physiological.
What negative affects does progesterone have in the GI tract?
Smooth muscle relaxation by progesterone: GI – Delayed emptying – constipation and reflux, Biliary tract – stasis, Pancreas – Increased risk of pancreatitis related to stones and smooth muscle.
What haematological changes occur in pregnancy?
Pregnancy is a pro-thrombotic state. ++ fibrin deposition at the implantation site. Increased fibrinogen & clotting factors. Reduced fibrinolysis, added to this: – Stasis; venodilation.
Consequence
Thromboembolic disease in pregnancy, warfarin crosses the placenta and is teratogenic.
Why are pregnant women often anaemic?
Plasma volume increases, red cell mass increases but not as much Physciological anaemia. However anaemia due to Fe- and folate deficiency can occur and haemoglobinopathies.
