physiology of pregnancy Flashcards
what cause the ovulation
day 14 - sudden surge of LH
where does the fertilisation/conception occur
in the follpian tube
when does the fertilised egg implant
day 23 into the uterus
what is the name of endometrium during pregnancy
decidua
how long does it take for a pregnancy test to be able to pick up a pregnancy
3-4 weeks after LMP
what produces b-hCG before week 12th of pregnancy
the corpus luteum that is implanted into the decidua
what does a pregnancy test test for?
beta-hCG
what produces the beta-hCG after week 12th of pregnancy
the placenta
Which hormone during pregnancy causes stress incontinence and acid reflux
progesterone - as it causes the relaxation of the smooth muscels
in what week can you see the gestational sac
4-5 weeks
in what week can you see yolk sac
5-6 weeks
in what week can you detect a foetal heart beat
6-7 weeks
what is the expected growth of the foetus before 12th weeks
double in size every week untill 12th week
in what week can you see the limb buds?
8th week
where is the most common place of fertilisation of the zygotes
ampulla of the fallopian tubes
when is the highest risk of miscarriage
first trimester
what is the major development of 1st trimister
foetus organ development
placenta growth and assume more major roles eg gas exchange, waste products removal, setiodgenesis
what is the major development of 2nd trimester
organ growth and enlargement
what are the intrinsic factors governing the foetal growth
maternal (genetics) - ethnic group, parity, height & weight
foetal - inherited disease, sex
what are the extrinsic factors governing the foetal growth
maternal - nutritional status, socioeconomical group, pre-existing conditions, environmetal alttuides, pregnancy related conditions (HTN, cardiac, renal)
foetal - TORCH syndrome, nutritional status, teratogenic substance eg tobacco
where would you find the fundus of the uterus at week 14?
just above the pubic sympthus
where would you find the fundus of the uterus at week 20 ?
directly underneath the umbilicus
where would you find the fundus of the uterus at week 36-40 ?
just below the ribs of the mother
how would you assess the foetus biophysical profile
foetal breathing movement
foetal movement
foetal tone
amniotic fluid volume
how would you assess the placementa?
by doppler studies
- look at the blood flow characteristic
- pulsatility index
- resistance index
what blood test are carried out in the booking visit
FBC - anaemia? - most commonly due to iron deficiency
GS+S - for future surgical purpose
Haemoglobinpathies - sickle cells, thalassaemia
blood group and antibody screen - rhesus
HIV
Hep B
Syphilis
Rubella
what can be done to avoid vertical transmission of HIV
treat mum with antiviral
treat baby postnatally for 6 weeks
C-section
avoid breastfeeding
what are some of the potentially sensitising events that might require Anti-D therapy
TOP ectopic pregnancy ECV blunt abdo trauma invasive uterine procedure eg aminocentesis or CVS intra-uterine death delivery
when are pregnant women checked for anti-D antibodies?
at booking visit,
week 28 and 34
who else should be checked for rhesus status?
other mums –> partner
what should you do if mum anti-D antibodies +ve
check for signs of foetal anaemia - peak systolic velocity of the foetal middle cerebral artery (MCA) once a week - if increased the FBS
what pre-natal treatment can be given to foetus with intra-utrine haemolytic anaemia?
blood transfusion
when are prophylactic Anti-D given to women who are rhesus -ve
IM anti-D immunoglobulin at week 28 and 34
what are the routine screening test available?
rhesus
haemoglobinpathies
foetal anmoalies - Down’s, edwards, pateu syndrome
infectious disease - HIV, hep B, syphilis, rubella
what screening tests for newborn are not routinely done?
Hep C - unless IVDU or previous obstetric cholestac
Chlamydia - encourage if under 25
Group B strep - unless swab/urine test are performed
what is the detection rate of combined test
85-90%
when can you do a CVS for Down’s syndrome diagnosis
from week 11
when can you do a aminocentesis for Down’s syndrome
from week 15
what are the risk of miscarriage when carrying out CVS
1%
what are the risk of miscarriage when carrying out amniocentesis
0.8%
when is the quadruple test offered?
between 15-20 weeks
what is in the quadruple test ?
blood test consists of 4 different tests
hCG
AFP
inhibin-A
Estriol
what is the detection rate of qadriple test
74%
what is the false +ve rate of qadriple test
4.1%
how long will it take for you to get the results of the CVS
rapid karyotyping (DNA analysisi) - within minutes
how long will it take for you to get the results of the aminocentesis
mayb take up to 3 weeks for culture
what is the indication of CVS
after screening test shows aneuploidy in 1st trimester
DNA analysis to diagnose inherited disease if there are parent carries a trait eg cystic fibrosis or thalassemia
what is the indication of aminocentesis
after screening test shows aneuploidy
DNA analysis to diagnosis inherited disease if there are parent carries a trait eg cystic fibrosis or thalassemia
inborn error
infection - confirm presence of TORCH syndrome
what are the food/drinks that a pregnant should avoid in pregnancy
caffeine - miscarriage
alcohol &liquor - developmental problems
deep sea fish - risk of high level of mercury - poisonous for foetus
meat related products - salmonella &bacteria which an be harmful
MSG
unpasteurised milk or cheese - could contain liisteria - critical to foetus
raw meats - risk of .COli
what is the time period of 1st trimester
up to 12th weeks
what is the time period of 2nd trimester
12-27 weeks
what is the time period of 3rd trimester
28 till birth
How do you confirm diagnosis of pregnancy
Beta-hCG and trans abdominal/ transvaginal USS
what is the lower limit of hemoglobin for a pregnant lady?
105 instead of 115 in non-pregnant lady
which foetal cell does maternal antibody target if the mother is rhesus -ve
Foetal RBC - leading to foetal haemolytic anaemia
can lead to erythropoiesis inadequately compensate which leads to high output cardiac failure –> foetal hydrop and death
mild case - neonatal anaemia or neonatal jaundice from HB break down
why does maternal antibody does not affect the first child but the second child?
initially, the antibody is IgM mediated which is too big to cross the placenta
re-exposure leading to memory B cell to produce IgG which can cross the placenta
what is the treatment to the baby whose mother has hep B
newborn straight onto vaccination program - 5 doses vaccine
If a baby is born to a mother who is either chronic/acute infected with HBV during pregnancy –> vaccination + 1x immunoglobulin at birth
what is the treatment for the baby whose mother has syphilis
full treatment before 36 weeks, otherwise newborn will get IV treatment
the detection rate of Non-invasive Prenatal test?
98% but costs 500 pounds
when is foetal anomaly USS conducted
from 18+6 till 20+6
what are some of the risk of CVS
vertical transmission of HIV and Hep B due to sampling from the placenta which has a mixture of maternal and foetal blood
miscarriage - 1%
what are some of the risk of amniocentesis
miscarriage - 1%
