OBS & GYNAE WK 4 Flashcards
Placenta-oxygen transport
passive diffusion
oxygen and nutrients pass thru placenta from mum -> foetus
CO2 and waste - foetus to mum
the supply of the foetus with oxygen is facilitated by what 3 factors??
fetal Hb - increase in carrying capacity of O2
higher Hb concentration in foetal blood
Bohr effect - foetal Hb can carry more O2 in PCO2
human placental lactose - when is it produced and what is it involved in ??
from wk 5
decreases insulin sensitivity in mothers
Importance of HCG
useful to monitor changes in levels eg. ectopic pregnancy (static), failing pregnancy (falling)
side effect = nausea and vomiting
levels fall from 12-14 wks
cardiovascular changes in pregnancy
increase in CO
increase in HR
BP DROPS DURING 2ND TRIMESTER (rises in 3rd trimester)
The _________ acts as a physiological
arteriovenous shunt
placenta
CRH pathway
CRH-> ACTH -> aldosterone / cortisol
ECG changes in pregnancy
sinus tachycardia
INVERTED T WAVES
Q wave
haematological changes in pregnancy
PV increases
RBC INCREASES
Hb is decreased by dilution
NEED MORE IRON
WHO definition of anaemia in pregnancy
1st tri = <110g/L
2nd and 3rd = <105g/L
postnatal = <100g/L
normally outside of pregnancy, normal level = 120-160g/L
Mx of major haemorrhage - trauma vs obstetrics (postpartum haemorrhage)
trauma = tranexamic acid
transfusion 1:1 RBC:FFP
obstetrics = tranexamic acid
transfusion 4 X RBC
resp changes in pregnancy
lung function changes occur due to progesterone increases and enlarging uterus interfering w lung function
O2 consumption increases
resp rate increases
TV increases
urinary system in pregnancy
increased urinary frequency, increased risk of urine infection, urinary incontinence, retention
postural changes affect renal function
supine position and lateral position - increase in renal perfusion??
_______ _____ contractions increase toward the end of pregnancy
cervical stretching causes ________ release
Braxton hicks - false labour
cervical stretching -> oxytocin release
3 stages of labour
1 - cervical dilatation (8-24hrs)
2 - passing of fetus thru birth canal (few mins - 120mins)
3 - placenta expulsion
what 2 hormones inhibit milk production
what stimulates milk production, and what is responsible for the release of milk??
estrogen and progesterone
prolactin - milk production
oxytocin
how to estimate gestational age - what’s most reliable
crown to rump length - head to butt
12 + 6 wks
head shouldn’t be tucked into chin
can also do head width circumference but this is less effective after 13 wks
FASP
foetal anomaly screening programme - around 20 wks??
can’t pick up all of them
eg. anencephaly, cleft lip, open spina bifida
placenta praevia
placenta is low lying in uterus and covers all or part of cervix
nuchal thickness - Trisomy Risk Assessment
First trimester
measure of skin thickness behind foetal neck using ultrasound
NIPT
aka
Cell free fetal DNA (cffDNA)
non-invasive prenatal testing
- detecting fatal DNA fragment in sample of blood taken from mum
- more specific and accurate
- expensive
The improved accuracy is important as cffDNA itself does not carry any risk of miscarriage, won’t harm the baby
diagnostic tests
amniocentesis
performed after 15 wks
chorionic villus sampling
after 12 wks
sticking needle into abdomen
why is red cell antibodies important ??
may cause fatal anaemia
anti-d injections given- at 28 wks
for blood transfusions
fetal growth - serial measurement of ____ is recommended at each antenatal appointment from 24 wks of pregnancy, as this improves prediction of a SGA neonate
SFH - SYMPHYSIS FUNDAL HEIGHT
small for gestational age
pre-eclampsia
what med is taken 12 - 36 wks ?
CLASSIC TRIAD??
hypertension in pregnancy, can affect every system
take aspirin 12weeks until 36 weeks
HYPERTENSION, PROTEINURIA, OEDEMA
definition of hypertension
140/90 mmHg on 2 occasions, 4 hrs apart
OR
160/110mmHg once
what meds to give for hypertension for women during pregnancy ??
what meds would you stop ??
labetalol (contraindicated in asthma)
Methyldopa (contraindicated in depression)
nifedipine
STOP ACEi/ARB and thiazides
gestational hypertension
2nd half of pregnancy
no systemic features or proteinuria compared to pre-eclampsia
continue antihypertensive - review after 2 wks
who are at high risk of PRE-ECLAMPSIA
Women at high risk are those with any of the following:
-hypertensive disease during a previous pregnancy
-chronic kidney disease
-autoimmune disease such as systemic lupus erythematosis or antiphospholipid syndrome
-type 1 or type 2 diabetes
-chronic hypertension.
EARLY VS LATE PRE-ECLAMPSIA
LATE IS MORE COMMON
EARLY - extensive villous, vascular lesions of placenta, higher risk of maternal and fetal complications
LATE - maternal factors
eclampic seizure
what causes pre-eclampsia??
2 stages
genetic/environment
not too sure but may be due to abnormal implantation and dysfunctional trophoblast invasion of the spiral arterioles -> endothelial damage and thrombosis
Stage 1 - abnormal placental perfusion
placental ischaemia
Stage 2 - maternal syndrome
an anti-angiogenic state associated with endothelial dysfunction
normal placentation vs pre-eclampsia
spiral artery from uterine artery - sending low volume of blood to placenta
in pre-eclampsia, trophoblast does not invade, endothelial damage, cytokines release, thrombosis
symptoms of pre-eclampsia
Headache
Visual disturbance
Epigastric / RUQ pain
Nausea / vomiting
Rapidly progressive oedema
Hyperreflexia
ix of pre-eclampsia
U&Es
serum urate
Blood tests: To assess kidney function, liver function, and clotting status.
mx of pre-eclampsia
definitive tx??
Antenatal screening - BP, urine, symptoms, Uterine Artery Doppler
Treat hypertension
Aspirin is used for prophylaxis against the development of pre-eclampsia. It is given from 12 weeks gestation until birth to women with one high risk factor or two (or more) moderate risk factors.
The only definitive curative treatment is the delivery of the placenta. It is also crucial to monitor the mother and foetus closely for complications.
in doppler - what is a sign of high resistance blood flow??
uterine artery doppler ultrasound
high resistance / poor flow, increased risk of pre-eclampsia
diastolic notch
Complications of pre-eclampsia
HELLP syndrome - rare liver and blood clotting disorder
“H” is for haemolysis – this is where the red blood cells in the blood break down
“EL” is for elevated liver enzymes (proteins) – a high number of enzymes in the liver is a sign of liver damage
“LP” is for low platelet count – platelets are substances in the blood that help it clot
eclampsia
Tonic-clonic (grand mal) seizure
MX OF ECLAMPSIA
MG SULPHATE
calories nutrition in pregnancy, 1st 2nd and 3rd trimester
1st and 2nd = normal, no need to increase calories
3rd last 12 weeks = increase 200
what supplements are needed for pre-pregnancy and during
400 mg folic acid
10mg vit d
deficiency in folic acid causes what
spina bifida
heart / limb defects
Listeriosis monocytogenes infection, and sources of infection
infection can cause in-utero infection
miscarriages, stillbirths and pre-term labour
unpasteurised milk, dairy products, soft cheeses, chilled ready to eat meals
mx of obesity in pregnancy
low dose aspirin
VTE score
oral glucose tolerance test (OGTT)
bariatric surgery mx
advise not to get pregnant until after 2 yrs
supplements and monitoring - vit d, iron, folic acid, calcium
nutritional screening - ferritin, folate
any foetal abnromalities ??
FASD
foetal alcohol spectrum disorder
most common cause of maternal death ??
cardiac disease
diabetes
hypertension
VTE
epilepsy
pregnancy-associated w 3-4 x risk of MI
link between asthma and pregnancy
poorly controlled asthma might affect foetal development
-> premature delivery, low birth weight babies
APS - what is it and clinical features??
Antiphospholipid syndrome
acquired thrombophilia, increased risk of blood clots
pregnancy loss, placental abruption, arterial/venous thrombosis
mx of APS
LDA
LMWH
what defects are associated w AEDs - anti epilepsy drugs??
neural tube defects
heart disorder
skeletal abnormalities
cleft palate
Describe the main causes of a small for gestational baby - maternal, placental, fetal
pre-term delivery and SGA due to FGR (fetal growth restriction)
maternal
placental
fetal
ix for small babies check
growth scan
Symphysial fundal height - cheap, easy
uterine artery doppler
umbilical artery doppler
MCA doppler
mx for small babies
-frequent scans for fatal growth, DVP and dopplers
-ensure regular BP + urine check
-advice on pre-eclampsia
-advice about increased risk of stillbirth and report reduced movements
-induction of labour
liquor pool
DVP - most accurate
prevention of SGA
HIGH RISK OF FGR
growth scans every 4 wks from 28 weeks
most common reason for measuring large for dates??
obesity
what is large for dates ??
symphyseal fundal height > 2cm for gestational age
fetal macrosomia
“big baby”
risks = labour dystocia, shoulder dystocia
mx of large for dates
conservative - doing nothing
EXLUDE DIABETES
IOL vs c/s delivery
gravidity vs parity
Gravidity is the total number of pregnancies, regardless of outcome.
Parity is the total number of pregnancies carried over the threshold of viability (24+0 in the UK).
eg. Patient is not pregnant, had one previous delivery = G1 P1
Patient is currently pregnant; had two previous deliveries = G3 P2
polyhydramnios and causes
excess amniotic fluid
deepest pool > 8 cm
AFI > 25cm
maternal - diabetes, red cell antibodies
baby getting a lot of sugar, pees more
fetal - viral infection, foetal anomaly eg. GI atresia
hydrops fetalis
clinical features of polyhydramnios
abdo discomfort
pre-labour rupture of membranes
pre-term labour
cord prolapse = EMERGENCY
CAN’T feel fetal parts
IX FOR POLYH
OGTT
Antibody screen
USS
MX FOR POLYH
serial USS
IOL by 40 wks
Labour
high order births - definition
presence of more than 1 fetes - twins, triplets
risks for multiple pregnancy
assisted contraception eg. IVF
Japan and china - rarest, 1in 500
fam history
tall women > short
zygosity and chorionicity
Zygosity: number of eggs fertilised to produce twins
Chorionicity: membrane pattern of the twins
monozygotic - splitting of a single fertilised egg
dizygotic - fertilisation of 2 ova by 2 spermatozoa
chronicity
dizygous - ALWAYS DCDA
monozygous - MCMA, MCDA, DCDA
cleavage - splitting
the later the cleavage happens, what happens??
more risk, higher risk of conjoined twins
morula days 1 -3 = DCDA (Each foetus has its own amniotic sac and its own placenta)
blastocyst 4-8 = MCDA (The twins are in two separate sacs but the placentas are joined)
implanted blastocyst 8-13 = MCMA (sharing 1 sac and placenta)
formed embryonic disc 13-15 = CONJOINED TWINS (sharing organs)
Determining Chorionicity
what sign do you look for in USS
US - shape of membrane and thickness
fetal sex
LAMBDA = DICHORIONIC
T SIGN = MONOCHORIONIC
MP - MULTIPLE PREGNANCY SYMPTOMS
EXAGGERATED PREGNANCY SYMPTOMS - EXCESSIVE SICKNESS
high AFP
TTTS
twin to twin transfusion
- rare pregnancy condition affecting identical twins or other multiples.
- sharing 1 placenta
syndrome w artery-vein anastomoses
before 26 wks = foetscopic laser ablation
after 26 = amnioreduction / septostomy
deliver 34-36 wks
why is pregnant woman sleeping on her back bad??
bc it is compressing on the IVC
should sleep on left side, where aorta is. this can handle.
arteries>veins
