Physiology of pregnancy Flashcards
Mechanical changes in pregnancy
pregnant person needs to lean backward and the curves of the spine change along its whole length. This is why pregnant people are more prone to back pain during (and after) pregnancy.
Hormone produced in pregnancy?
- what effect does this have on
relaxin
- increased pliability and extensibility of connective tissue. Ligamentous joints become less stable.
What joints are particularly affected In pregnancy?
symphysis pubis and sacroiliac joints
the normal pubic symphyseal gap increases by?
4-5mm increase on average by another 3mm. (*symphysis pubis dysfunction).
When does joint loosening occur
load on hip joints at term?
10 weeks and will return to normal 4-12 weeks post partum.
By term there is an increased load on the hip joints of 2.8 times the normal value when standing.
what acts against maternal insulin
Human placental lactogen
what are Fatty acids vital for
fetal organogenesis.
normal female weight gain?
10-14 kg
regarding eating food through pregnancy- what happens?
- what do hormones cause relaxation of? likely to cause?
food moves more slowly into the stomach and there is delayed emptying
- lower oesophageal sphincter - more likely for contents to reflux into oesophagus
The mechanical pressure from an enlarging uterus makes makes what worse as does delayed gastric emptying?
mechanical pressure from an enlarging uterus
what % of women will develop oedema?
80%
why do women develop oedema in pregnancy?
physiological sodium and water retention and a decreased ability to excrete a sodium and water load
increased BV in pregnancy leads to.. why is this?
decreased venous return due to compression of the inferior vena cava from the gravid uterus also contributes to peripheral oedema
oedema can be an important sign of
pre eclampsia
breast changes in pregnancy include?
pigmentation of the areola and nipple and a secondary areola appears
- Montgomery tubercles appear on the areola. Colostrum like fluid can be expressed from the end of the 3rd month.
what does the liver produce more of in pregnancy?
do t3 and t4 change?
thyroid binding globulin (TBG) but the total level of thyroxine (T4) and tri iodothyronine (T3) also increase so FREE T3 and FREE T4 (active) levels remain the same.
what is pregnancy associated with?
a relative iodine deficiency
why do maternal iodine requirements increase in pregnancy?
- urinary exception and GFR?
- why does the thyroid gland work harder?
iodine is actively transported to the fetoplacental unit and urinary iodine excretion is doubled because of an increased glomerular filtration rate and decreased renal tubular reabsorption. The thyroid gland therefore works harder to increase its iodine uptake and may hyperthrophy to ensure adequate levels of iodine trapped.
What can be associated with a biochemical hyperthyroidism (increased levels of T4 and suppressed TSH?
- why is this?
Hyperemesis gravidarum
- because the beta sub unit of BHCG (a pregnancy hormone) is structurally very similar to TSH.
How is Hyperemesis gravidarum treated?
betablockers such as propanolol can be used for symptom control of tachycardia caused by the high levels of T4. This biochemical hyperthyroidism will resolve with the hyperemesis.
what is overactive thyroid caused?
Thyrotoxicosis
Thyrotoxicosis is often due to underlying?
Grave’s disease
What can the antibodies that cause Graves disease do?
what are these antibodies called?
TSH receptor antibodies
- can cross the placenta and cause fetal and/or neonatal hyperthyroidism
what is the foetus dependent on?
maternal thyroid functio
when does fetal thyroid development begin?
12 weeks gestation.
there Is a general state of immunosuppression in pregnancy - why is this?
- what does this do?
to allow for fetal tolerance
- increases the maternal susceptibility to infection
What conditions can improve during pregnancy?
Crohns disease, rheumatoid arthritis
the heart has to work harder due to? (4)
- what does it have too pump blood through?
- of the growing fetus, the weight gain associated with pregnancy and the increased oxygen requirements of the uterus and breasts
previous or undiagnosed cardiac problems may show in pregnancy.. what my happen?
- may lead to maternal and fetal death
-
What is the leading indirect cause of maternal death in the UK?
cardiac disease