Large for dates Flashcards
What is the definition of large for dates
symphyseal fundal height >2cm for gestational age
list causes for being large for dates
wrong dates foetal macrosomia polyhydramnios diabetes mellitus multiple pregnancy
What might happen if the dates are wrong
Late booker
concealed pregnancy
travelled from abroad
What does foetal macrosomia mean
big baby
How do you diagnose foetal macrosomia
USS scan
estimated foetal weight (EFW) >90th centile
abdominal circumference (AC) >97th centile
what are the risks of having a big baby
anxiety to mother and clinician
labour dystocia
shoulder dystocia
post partum haemorrhage
When is diagnosing foetal macrosomia most accurate
<38 weeks
USS overestimates baby’s size, true or false
TRUE
Management of foetal macrosomia
exclude diabetes
reassure
surveillance
discuss delivery options
if a baby is >4.5kg, what delivery option should be considered
c-section
What is polyhydramnios
excess amniotic fluid
How do you diagnose polyhydramnios
Amniotic Fluid index AFI > 25cm
Deepest Pool DP >8cm
Subjective impression
what are the causes for polyhydramnios
maternal: DM
foetal: anomaly, monochorionic twin pregnancy, hydrops fetalis, viral infection
idiopathic
Symptoms + signs of polyhydramnios in the mother
Abdominal discomfort pre labour rupture of membranes pre term labour cord prolapse = obstetric emergency large for dates malpresentation tense shiny abdomen inability to feel foetal parts
Investigations for polyhydramnios
OGTT to exclude DM
USS - anomalies, multiple pregnancies
serology
Ab screen
Management of polyhydramnios
explain and discuss
surveillance
IOL by 40 weeks
Define multiple pregnancy
presence of more than 1 foetus in the uterus
twins, triplets etc
Risk factors for multiple pregnancy
Assisted conception (less so now) Ethnicity - African FH increased maternal age increased parity tall>short
How do monozygotic twins arise
splitting of single fertilised egg
How do dizygotic twins arise
from fertilisation of 2 separate ova by 2 separate sperm
Describe dichorionic-diamniotic twins
DCDA
2 placentas + 2 amniotic sacs
occurs in days 1-3
can occur in mono + dizygotic twins
Describe monochorionic-diamniotic twins
MCDA
1 placenta + 2 amniotic sacs
occurs in days 4-8
monozygotic twins
Describe monochorionic-monoamniotic twins
MCMA
1 placenta + 1 amniotic sac
occurs in days 8-13
monozygotic twins
at higher risk for complications
Describe conjoined twins
Both babies are joined together
When is USS confirmation done for multiple pregnancy
12 weeks
What does the lambda sign on USS mean
DCDA twins
What does the T sign on USS mean
MCDA twins
What are symptoms and signs of multiple pregnancy in the mother
exaggerated symptoms eg hyperemesis gravidarum
high AFP
large for dates uterus
multiple foetal poles
What are complications of multiple pregnancy
higher mortality congenital anomalies pre term birth growth restriction anaemia HG pre-eclampsia antepartum haemorrhage twin - twin transfusion syndrome TTTS twin anaemia polycythaemia sequence TAPS absent/reversed end diastolic volume
what is TTTS
arteriovenous anastamosis
donor twin perfuses recipient twin
oligohydramnios - polyhydramnios (oly-poly)
Management of TTTS
fetoscopic laser ablation
amnioreduction / septostomy
deliver at 34-36/40
When should DCDA twins be delivered
37-38 weeks
When and how should MCDA twins be delivered
after 36 weeks with steroids
How should MCMA twins be delivered
c-section
Objectives of multiple pregnancy delivery
consultant led epidural analgesia foetal monitoring oxytocin infusion after delivery of 1st baby intertwin time < 30 min be aware of PPH
What are types of diabetes in pregnancy
Pregestational - T1+2DM
Gestational - starts in pregnancy and resolves by delivery
Complications of pregestational DM only in pregnancy
congenital anomalies
miscarriage
intra uterine death
worsening of diabetic complications - retinopathy, nephropathy
complications of both pregestational and gestational DM in pregnancy
pre eclampsia polyhydramnios macrosomia shoulder dystocia neonatal hypoglycaemia
Above what HbA1c level should conception/pregnancy be avoided
HbA1c > 86 mmol/L
What HbA1c level should be aimed for pre conception
48mmol/L
What should be advised in pre pregnancy counselling for diabetics
Control HbA1c
stop teratogenic drugs
Folic acid 5mg
How do you manage T1DM in pregnancy
SC inulin low dose aspirin from 12/40 onwards 5mg folic acid continuous DM checks and screens growth scans every 4 weeks from 28/40 deliver at 38/40
How do you manage T2DM in pregnancy
PO metformin (stop SURs!) low dose aspirin from 12/40 onwards 5mg folic acid continuous DM checks and screens growth scans every 4 weeks from 28/40 deliver at 38/40
What are RF for GDM
previous GDM in previous pregnancy FH of DM BMI>30 ethnicity previous big baby polyhydramnios foetal macrosomia diagnosed glycosuria
How is OGTT carried out
venous fasting blood sugar taken
give 75g glucose solution to drink
minimal activity in 2 hour break
measure 2 hour venous glucose
What are the SIGN guidelines for diagnosing GDM in OGTT
fasting glucose >5.1
2 hour glucose >8.5
How many times a day should blood glucose be checked
x4 /day
What are the glycaemic targets for
fasting glucose
1 hour post meal
fasting glucose: 3.5-5.5
1 hour post meal <7.8
What delivery timings are advised in:
- GDM with insulin
- GDM with metformin
- GDM with diet control
- 38-39 weeks
- 39-40 weeks
- 40-41 weeks
How should GDM be followed up after delivery
fasting blood sugar measures 6-8 weekly
annual FBS and lifestyle changes
