large for gestational dates Flashcards
what is large for dates?
SFH > 2cm for gestational age
reasons for large for dates?
- multiple pregnancy
- wrong dates
- fetal macrosomia
- polyhydramnios
how do you diagnose fetal macrosomia?
- USS EFW (estimated fetal weight)
what is the diagnosis for fetal macrosomia?
USS EFW >90th centile
what are risks of fetal macrosomia?
- clinician and maternal anxiety
- labour dystocia
- shoulder dystocia - more w diabetes
- PPH
how accurate is USS?
- commonly overestimated
- training essential - operator dependent
- BMI of women
- margin of error up to 10%
management for large for dates?
- exclude diabetes
- reassure
- conservative vs IOL vs C/S delivery (based on previous pregnancies, complications etc)
- ‘IOL should not be carried out simply because a baby is large for ges age (macrosomic)’
deepest pool is 9.56cm what does this image show?
- polyhydramnios
what is polyhydramnios
amniotic fluid index AFI >25cm
deepest pool >8cm
= excess amniotic fluid in the amniotic sac
causes of polyhydramnios?
maternal - diabetes, red cell antibodies
fetal - anomaly (GI atresia, cardiac, tumours), monochorionic twin pregnancy, hydrops fetalis (Rh isoimmunisation), viral infection (erythrovirus B19, toxoplasmosis, CMV)
idiopathic
clinical features of polyhdramnnios?
- abdominal discomfort
- pre-labour rupture of membranes
- preterm labour
- cord prolapse
- inability to feel fetal parts
- tense shiny abdomen
- malpresentation
- large for dates
how can you confirm diagnosis of polyhyramnios?
- USS
DVP >8cm
AFI >25
subjective
investigations for polyhydramnios?
- OGTT
- viral serology, toxoplasmosis, CMV, parvovirus
- antibody screen
- USS - fetal survey - lips (ability to swallow), stomach bubble
polyhydramnios management
- patient info - complications inc preterm rupture of membranes
- serial USS - growth, LV, presentation
- IOL by 40 weeks
- labour
i.e. risk malpresentation
risk of cord prolapse -> if happens at home chances of survival are slim
risk of preterm labour
risk of PPH
neonatal examination
what is this position used in the management of?
- cord prolapse
- knee-chest position
what is a cord prolapse?
- umbilical cord prolapse occurs when cord descends through cervix and is alongside or below presentating part of fetus
- obstetric emergency - fetal mortality 91/100
when should you suspect cord prolapse?
- non-reassuring fetal heart trace and absent membranes
multiple pregnancy risks?
- assisted conception - clomid, IVF
- race - african
- geography
- family history
- inc maternal age
- inc parity
- tall women > short women
monozygous twins
splitting of a single fertilised egg (30%)
dizygotic twins?
- fertilisation of 2 ova by 2 spermatozoa (70%)
chorionicity?
- 1 placenta/2 placentas
dizygous is always what?
DCDA
monozygous options?
MCMA
MCDA
DCDA
conjoined
-> depends on time of splitting of fertilised ovum
chorioncity
study
monochorionic twins
Day0-3 after fertilisation: Dichorionic, diamniotic (DCDA)
Day 4-7 after fertilisation: Monochorionic , diamniotic (MCDA)
Day 8-14 after fertilisation: Monochorionic , monoamniotic (MCMA)
Day 15 after fertilisation onwards: Conjoined twins
determining chorionicty?
US
- shape of membrane and thickness of membrane
- twin peak at 11-13+6 weeks (CRL 45-84mm)
- placental masses, appearance of membrane attachment and membrane thickness (Lamda sign)
- FETAL SEX
why is determining chorioncity important?
- monochorionic/monozygous twins at higher risk of px complications
what is lambda sign?
multiple pregnancy symptoms and signs?
symptoms
- exaggerated pregnancy symptoms i.e. excessive sickness -> hyperemesis gravidarum
signs
- high AFP
- large for dates uterus
- multiple fetal poles
how many weeks can you confirm a multiple pregnancy?
- USS confirmation at 12 weeks
complications of multiple pregnancy?
- higher perinatal mortality - 6x higher than singleton
- fetal complications - congenital anomalies e.g. acardiac twin, IUD (single/both), pre term birth, growth restriction (both/discordant), cerebral palsy (twins 8x higher, triplets 47x higher), twin to twin tranfusion - oligohydramnios and polyhydramnios
maternal complications of multiple pregnancy?
- hyperemesis gravidarum
- anaemia
- pre eclampsia
- antepartum haemorrhage - abruption, placenta praevia
- preterm labour
- caesarean section
antenatal mx for multiple pregnancy?
- consultant led care
- twin/multiple pregnancy clinic
- clinic appointments: MC: every 2 weeks, DC: every 4 weeks
- maternal education - preterm labour and risks, support, TAMBA
antenatal mx medications for multiple pregnancy?
- Fe supplementation
- low dose aspirin
- folic acid
antenatal mx for USS of multiple pregnancy?
- MC 2 weekly from 16/40
- anomaly USS 18-20 weeks
- DC 4 weekly
monochorionic twins mx?
- MC 2 weekly from 16/40
- anomaly USS 18-20 weeks
- deep vertical pool, bladder and umbilical artery doppler (UAPI), EFW
monochorionic twins complications?
- single fetal death
- selective growth restriction (sGR)
- twin-to-twin transfusion syndrome (TTTS)
- twin anaemia - polycythaemic sequence (TAPS_
- absent EDV (AEDV) or reversed (REDV)
- twin-to-twin transfusion syndrome (TTTS)
what is twin-to-twin transfusion syndrome?
- syndrome w artery-vein anasotomoses. donor twin perfuses the recipient twin
- rare after 26/40
how do you diagnose TTTS
- oligohydramnios - polyhydramnios (oly-poly)
complications of TTTS
mortality >90% w no treatment
neurological morbidity 37% and high in surviving twin if IUD
tx of TTTS?
- before 26/40 - Rx fetoscopic laser ablation
- > 26/40 - amnioreduction/septostomy
- deliver - 34-36/40
complex multiple birth?
- MCMA - monochorionic monoamniotic twins
-> risk for cord entanglement, higher risk of fetal death, deliver by C section 32-34+0 weeks
-> conjoined twins - MDT, specialised centres
delivery of multiple pregnancies
Timing:
DCDA Twins deliver 37-38 weeks
MCDA Twins deliver after 36+0 weeks with steroids.
Mode of Delivery
Triplets or more – Caesarean section
MCMA- Caesarean section
Twins if twin one cephalic aim for vaginal delivery
Much greater risk of Caesarean section (approx 50%)
labour of multiple pregnancy
- high risk
- consultant led unit
- epidural analgesia
- fetal monitoring: USS and FSE
- syntocinon after twin 1
- USS to confirm presentation
- intertwin delivery time <30 min
- risk of PPH - active 3rd stage
what is syntocinon?
- hormone causes uterus to contract
diabetes important mx
- high dose folic acid 5mg - 3 months before conception to 12 weeks of pregnancy
complications of pre-existing diabetes in pregnancy
all relate to poor control
- congenital anomalies - related to high HBA1C at booking
- miscarriage
- intra uterine death
- worsening diabetic complications e.g. retinopathy, nephropathy
pre-existing and gestational complications of diabetes
- pre-eclampsia
- polyhydramnios
- macrosomia
- shoulder dystocia
- neonatal hypoglycaemia
type 2 DM risk factors?
- rising prevalence
- older
- overweight/obese
- asian, middle eastern, african, afro-carribean, insulin resistance
type 1 DM risk factors?
- 5-10% prevalence
- younger
- slimmer
- white
- insulin deficiency
aim for type 1/type 2 diabetes?
- 48mmol/mol (6.5%)
- avoid pregnancy if HbA1c above 86 (10%)
- stop ACEi, cholesterol lowering agents
- determine macrovasc and microvasc complications
- high dose folic acid 5mg!!! 3 months prior and up to 12 weeks
