Physiological Changes In Pregnancy Flashcards
Overview of the physiological changes in pregnancy
Changes to the Uterus, Cervix and Vagina during pregnancy
The size of the uterus increases from around 100g to 1.1kg during pregnancy. There is hypertrophy of the myometrium and the blood vessels in the uterus. Increased oestrogen may cause cervical ectropion and increased cervical discharge. Oestrogen also causes hypertrophy of the vaginal muscles and increased vaginal discharge. The changes in the vagina prepare it for delivery, however they make bacterial and candidal infection (thrush) more common.
Before delivery, prostaglandins break down collagen in the cervix, allowing it to dilate and efface during childbirth.
Hormonal Changes in pregnancy
The anterior pituitary gland produces more … (3)
The anterior pituitary gland produces more ACTH, prolactin and melanocyte stimulating hormone in pregnancy.
Higher ACTH levels in pregnancy cause a rise in…
steroid hormones, particularly cortisol and aldosterone. Higher steroid levels lead to an improvement in most autoimmune conditions and a susceptibility to diabetes and infections.
Increased prolactin in pregnancy acts to suppress …
Increased prolactin acts to suppress FSH and LH, causing reduced FSH and LH levels.
Increased melanocyte stimulating hormone in pregnancy causes…
Increased melanocyte stimulating hormone causes increased pigmentation of the skin during pregnancy, resulting in skin changes such as linea nigra and melasma.
skin changes such as linea nigra and melasma are as a result of …
Increased melanocyte stimulating hormone causes increased pigmentation of the skin during pregnancy, resulting in skin changes such as linea nigra and melasma.
What happens to thyroid hormones during pregnancy?
TSH remains normal, but T3 and T4 levels rise.
HCG levels rise, roughly doubling every 48 hours until they plateau around..-..weeks, then gradually start to fall.
HCG levels rise, roughly doubling every 48 hours until they plateau around 8 – 12 weeks, then gradually start to fall.
Progesterone levels rise throughout pregnancy. Progesterone acts to maintain the pregnancy, prevent contractions and suppress the mother’s immune reaction to fetal antigens. The corpus luteum produces progesterone until … weeks gestation. The … produces it during the remainder of the pregnancy.
Oestrogen rises throughout pregnancy, produced by the ..
Oestrogen rises throughout pregnancy, produced by the placenta.
There are several cardiovascular changes during pregnancy:
Increased blood volume
Increased plasma volume
Increased cardiac output, with increased stroke volume and heart rate
Decreased peripheral vascular resistance
Decreased blood pressure in early and middle pregnancy, returning to normal by term
Varicose veins can occur due to peripheral vasodilation and obstruction of the inferior vena cava by the uterus
Peripheral vasodilation also causes flushing and hot sweats
.. and .. increase in later pregnancy, to meet the increased oxygen demands.
Tidal volume and respiratory rate increase in later pregnancy, to meet the increased oxygen demands.
A number of changes in the kidneys happen during pregnancy:
Increased blood flow to the kidneys
Increased glomerular filtration rate (GFR)
Increased aldosterone leads to increased salt and water reabsorption and retention
Increased protein excretion from the kidneys (normal is up to 0.3g in 24 hours)
Dilatation of the ureters and collecting system, leading to a physiological hydronephrosis (more right-sided)
Haematology Changes in pregnancy
There is increased red blood cell production in pregnancy, leading to higher iron, folate and B12 requirements. Plasma volume increases more than red blood cell volume, leading to a lower concentration of red blood cells. High plasma volume means the haemoglobin concentration and red cell concentration (haematocrit) fall in pregnancy, resulting in anaemia.
Clotting factors such as fibrinogen and factor VII, VIII and X increase in pregnancy, making women hyper-coagulable. This increases the risk of venous thromboembolism (blood clots developing in the veins). Pregnant women are more likely to develop deep vein thrombosis and pulmonary embolism.
