Pregnancy and Childbirth Flashcards
Why do women get morning sickness?
because early development of the embryo is toxin sensitive so the vomit reflex is sensitised to try and reduce the chance of toxins entering the body that might harm the baby
Why do pregnant women get lower back pain?
due to the increased inward curvature of the lower spine during pregnancy
why do the breasts enlarge?
to prepare for lactation
Why is heart rate increased in pregnant women and by how much
10-15% to meet the additional demands put on the body by the fetus
why does blood volume increase in pregnancy and by how much?
30-50% increase to meet the additional demands of the fetus with regards to nutrients in the blood and oxygen
why does oxygen consumption increase in pregnancy and by how much?
to meet the added oxygen demands of the fetus
why do pregnant women find it difficult to breathe? and what is this called?
dyspnea this is because the diaphragm is unable to fully flatten
Why do pregnant women get edema?
due to compression of the fetus on the pelvis which decreases venous return.
why do pregnant women get heart burn?
due to the fetus putting pressure on the stomach which may force the stomach contents up into the esophagus
why do pregnant women pee so much?
due to additional pressure being on the bladder which means that it cannot store the same volume of urine.
why do pregnant women feel constipated?
due to compression of the rectum
what is the 12 week sonogram for?
confirming pregnancy, identifying multiple pregnancy, determining fetus position, assessing the size of the fetus, due date.
what is the nuchal translucency test for?
this looks at fluid retention at the back of the neck, there is a correlation between this and trisomy 21, however this test gives a false +ve in 20 of cases
What is the Chorionic Villus test and when is it done?
as early as 8 week, this take 30g of chorionic villi sample to test for abnormalities in the fetus
What is amniocentesis and when is this carried out?
14/18 weeks, taking amniotic fluid to analyse the fetal cells and any dissolved solutes
what is the risk with doing an amniocentesis?
in there is a 0.5% risk of spontaneous abortion
what is the risk of abortion with a chorionic villus test?
1-2% risk of spontaneous abortion
what is the point in the 20 week ultrasound?
At this point the physical structures of the fetus are far more visible and so anatomical abnormalities can be searched for
what is the fancy name for labour?
parturition
how is the inhibiting effect of progesterone on labour overome?
by a rise in Estrogen
why does estrogen rise before labour so sharply in the mothers blood?
increased levels of corticotrophin releasing hormone
anterior pituitary of fetus secretes ACTH
so the fetal adrenal gland makes cortisol and DHEA
the placenta makes DHEA into estrogen
what does increased estrogen cause before labour?
increased oxytocin receptors on uterine muscle fibres and the muscle fibres form gap junctions with each other
what is released and where from to cause uterine contractions?
oxytocin is released from the posterior pituitary
what does relaxin do where does it come from?
comes from the placenta and aids dilation of the cervix
what does the estrogen cause the placenta to release?
prostaglandins that induce the production of enzymes that break down collagen fibres in the cervix
What are three stages of labour?
the dilation stage the expulsion stage and the placental stage
how long does the dilation phase last?
6 to 12 hours
what is the dilation phase defined as?
the time from the onset of labour to the complete dilation of the cervix
what kind of smooth muscle contracts to dilate the cervix?
The longitudinal smooth muscle
how long can the stage of expulsion last?
10 minutes and several hours
what is the expulsion phase?
the time from the complete dilation of the cervix to the delivery of the baby
why does the babys head have to be rotated as it leave the body?
because the inlet and outlet proportions of the pelvis are different. the pelvis is at first wider laterally but then the outlet is wider anterior posterior-ly
why is a perineum tear risky and what can be done about this?
the tear can propagate to the anus and damage the anal sphincter. an episiotomy can be done to direct the tear away from the sphincter to stop the tear for reaching this
what happens when the fetuses head is int the pelvis?
intermittent hypoxia which is highly stressful for the fetus
what hormones are secreted by the fetal adrenal medulla?
adrenaline and noradrenaline this protects the fetus agaisnt the stress of birth and may also prepare in a fight or flight still for the extauterine conditions
why is the umbilical cord attached for a bit and not cut straight away?
to ensure the Fetal blood is maximally oxygenated
what are the benefits of vernix?
acts as a lubricant
protects the newborn against heat loss
protects the fetus from harmful pathogens
how is the placenta lost?
the placenta detaches from the uterus and then it is delivered using strong uterine contractions
how do the strong uterine contractions of the placental birth help reduce risk of hemorrhaging?
they cause the blood vessel of the uterus to vasoconstrict which may have been torn during expulsion stage
what is the puerperium stage?
the 6 week period after labour where the maternal reproductive organs and physiology return to their pre-pregnancy stage
what is involution?
the catabolism of uterine tissue to cause a massive reduction in uterus size
what happens to the cervix?
it regains its eleasticity and returns to its firmness
what is the lochia
discharge, lasts 2-4 weeks post birth made up of bloood and serous fluid from the previous site of the placenta
why is it important to induce labour when 2 weeks late?
the ageing of the placenta may cause fetal brain damage as it may not supply adequate oxygen and nutrients
how can labour be induced?
using oxytocin or surgical delivery
